Founded in 2020, “Medical Hypothesis, Discovery & Innovation in Optometry” is an international, open-access, double-blinded peer-reviewed, quarterly journal that considers publications related to optometry. The aim is to present a scientific medium of communication for researchers in the field of optometry, fostering collaboration and the exchange of ideas among professionals dedicated to advancing visual science. By providing a platform, the journal promotes the dissemination of knowledge that can contribute to the eye care practices and education. It is of interest to a broad audience of visual scientists, practitioners, and trainees, and publishes original articles, comprehensive reviews, case reports, and insightful commentaries after a rigorous peer-review process to ensure high-quality contributions. Each publication is meticulously selected to reflect the journal’s commitment to excellence and relevance in the field. The journal is affiliated with and published by the “IVORC,” a registered non-profit corporation in Austin, Texas, United States, which ensures that all operations are guided by principles of integrity and scientific rigor. Additionally, we provide English editing for papers as a complimentary free-of-charge service, facilitating authors from diverse academic backgrounds to present their research clearly and professionally, thus enhancing the overall quality of submissions to the journal.
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Spring 2026
Vol. 7 No. 1 (2026)
Visual rehabilitation with scleral lenses after corneal transplantation
Fatemeh Riazi, Mostafa Naderi, Seyed-Hashem Daryabari, Abbas Riazi
Medical hypothesis, discovery & innovation in optometry, Vol. 7 No. 1 (2026), 27 May 2026 , Page 1-7
https://doi.org/10.51329/mehdioptometry239
Background: Patients undergoing corneal transplantation often present with high astigmatism and corneal irregularity, making conventional contact lens fitting difficult and limiting tolerance to standard optical correction. We aimed to evaluate the effect of scleral lens fitting on visual rehabilitation in patients following lamellar or penetrating keratoplasty by assessing visual acuity, contrast sensitivity, and patient satisfaction.
Methods: Patients who had undergone keratoplasty and were considered suitable candidates for scleral lens fitting were enrolled in this prospective interventional study. All participants underwent comprehensive ophthalmic and optometric examinations prior to lens fitting. Visual acuity and contrast sensitivity were measured using a standard Snellen visual acuity chart and the Melbourne Edge Test under standardized back-illuminated conditions, with results recorded in decimal notation and decibels (dB), respectively. Refractive error was assessed by autorefractometry, followed by over-refraction and subjective and objective refinement to determine the final lens power. Diagnostic fitting was performed using trial scleral lenses, and anterior segment optical coherence tomography was utilized to assess lens fit. Visual and refractive parameters were recorded before and after optimal scleral lens fitting. Patient-reported satisfaction was assessed 1–2 weeks after lens dispensing using a 0–10 subjective rating scale, where scores 8–10 indicated complete satisfaction, 5–7 satisfaction, 2–4 dissatisfaction, and 0–1 complete dissatisfaction.
Results: Eighteen eyes of 12 post-keratoplasty patients, 7 (58%) men and 5 (42%) women, were evaluated. Mean (standard deviation [SD], range) age was 45.6 (3.9, 22–67) years. Mean (SD) visual acuity improved significantly from 0.15 (0.12) decimal before lens fitting to 0.77 (0.33) decimal after scleral lens wear (P < 0.001). Mean contrast sensitivity increased significantly from 14.55 (3.82) dB to 20.33 (2.35) dB following scleral lens fitting (P < 0.001). All patients reported satisfaction with scleral lens wear, including complete satisfaction in nine (75%) patients and satisfaction in three (25%) patients.
Conclusions: Post-keratoplasty ametropia and irregular astigmatism frequently limit visual rehabilitation with conventional optical correction methods. Scleral lenses offer an effective approach for correcting postoperative refractive irregularities and significantly enhance visual acuity and contrast sensitivity, while yielding high patient satisfaction at two weeks after lens fitting.
Ocular morbidity among elderly residents of old age homes in East Nepal
Akrima Riyaz, Sanjay Kumar Sah, Pankaj Ray Adhikari, Rajiv Ranjan Karn, Sarafat Ali Musalman
Medical hypothesis, discovery & innovation in optometry, Vol. 7 No. 1 (2026), 27 May 2026 , Page 8-14
https://doi.org/10.51329/mehdioptometry240
Background: With the rapid growth of the aging population in Nepal, the number of older adults residing in old age homes has increased substantially. Elderly individuals living in institutional settings are at higher risk of visual impairment (VI) and blindness compared to their community-dwelling counterparts, largely due to limited access to eye care services and underutilization of available interventions. This study aimed to assess the prevalence of ocular morbidity and to identify the major causes of VI and blindness among elderly residents of old age homes in East Nepal.
Methods: A community-based cross-sectional study was conducted among individuals aged 60 years or older living in six old age homes in Koshi Province, Nepal. Distance visual acuity was assessed using an E-optotype Snellen chart at 6 meters, near visual acuity was evaluated using a reduced Snellen chart at 33 cm under standard illumination. Objective refraction was performed using a streak retinoscope, and both uncorrected and best-corrected distance visual acuity (UCDVA and BCDVA) were recorded for the better-seeing eye. Comprehensive ocular examination, including anterior and posterior segment evaluation, was performed using standard clinical techniques. In cases with multiple ocular conditions, the primary cause of VI was determined based on the condition contributing most to vision loss.
Results: A total of 236 elderly residents were enrolled, with a mean (standard deviation) age of 70.5 (9.5) years (range: 60–02). Nearly half of the participants (n = 116, 49.2%) were aged 60–69 years, the majority female (n = 146, 61.9%). Ocular morbidity was detected in 94.7% (n = 447) of eyes. The prevalence of VI and blindness based on presenting visual acuity was 57.4%; this decreased to 39.4% following refractive correction, indicating an 18% absolute reduction. Cataracts (n = 229 eyes, 48.5%) were the leading cause of VI and blindness, followed by refractive error, corneal opacity, retinopathy, and glaucoma. A statistically significant association was observed between age and VI/blindness (P < 0.05), whereas no significant association was found with sex (P > 0.05).
Conclusions: VI and blindness are highly prevalent among elderly residents in old age homes, with a substantial proportion attributable to avoidable causes. Timely refractive correction, regular comprehensive eye examinations, and increased uptake of cataract surgery could significantly reduce the burden of VI and improve quality of life in this vulnerable population. Strengthening outreach eye care services and integrating routine vision screening into residential care systems are essential to address this largely preventable public health challenge.
Binocular vision dysfunction after polytrauma
Seyed Meysam Yekesadat, Aziz Rasooli, Mohammad Sedaghat, Mahdi Ebrahimi, Nima Rastegar Rad, Meisam Sharifi, Mohammad Vaseie
Medical hypothesis, discovery & innovation in optometry, Vol. 7 No. 1 (2026), 27 May 2026 , Page 15-22
https://doi.org/10.51329/mehdioptometry241
Background: Binocular vision dysfunction is frequently overlooked in polytrauma care despite its established impact on reading, driving, and return to work. We aimed to determine the prevalence and patterns of binocular vision dysfunction in polytrauma patients with ocular involvement and to identify independent clinical predictors.
Methods: We conducted a retrospective cohort study of adults (aged 18 years or older) admitted to Sina Hospital Trauma Center, Tehran between January 2021 and December 2023 with an Injury Severity Score (ISS) 16 or more and ophthalmology-confirmed ocular involvement. Four binocular parameters; near point of convergence, stereoacuity, fusional vergence amplitudes, and accommodative facility, were extracted from consultation records when available. Prevalence estimates were calculated using the Wilson score method, and multivariable logistic regression identified independent predictors.
Results: Among 2923 polytrauma admissions, 438 patients (15.0%) had ocular involvement; 312 (71.2%) had complete binocular data (mean [standard deviation] age 37.8 [14.2] years; 84.6% [n = 264] male). At least one binocular dysfunction was identified in 134 patients (42.9%; 95% confidence interval [CI], 37.4-48.6). Convergence insufficiency was most common (n = 119, 38.1%; 95% CI, 32.8–43.7), followed by reduced stereopsis (n = 87, 27.9%; 95% CI, 23.1–33.2), accommodative dysfunction (n = 67, 21.5%; 95% CI, 17.2–26.4), and reduced fusional vergence amplitude (n = 54, 17.3%; 95% CI, 13.4–22.0). Only 24.7% (n = 77) of patients received formal optometric referral during acute admission. Independent predictors were blunt orbital trauma (adjusted odds ratio [aOR] 2.81, 95% CI, 1.67–4.73), concomitant traumatic brain injury (aOR 2.14, 95% CI, 1.29–3.55), and age 18-35 years (aOR 1.92, 95% CI, 1.12–3.28) (all P < 0.05).
Conclusions: Binocular vision dysfunction affects nearly half of polytrauma patients with ocular involvement yet is substantially under-recognized and under-referred. Incorporating a brief binocular screening into routine post-trauma ophthalmologic assessment may represent a low-cost strategy to mitigate long-term visual and functional disability. Future prospective, multicenter studies employing standardized optometric assessment protocols and longitudinal follow-up are warranted to better define the natural history of these observed binocular dysfunctions and to evaluate the impact of early detection and targeted intervention on functional outcomes.
Digital eye strain among the Omani university population: prevalence, contributing factors, and preventive practices
Amna Almur, Wejda Mohammed, Al Hanoof Khalifa, Shahd Mohammed, Yahya Said, Thilagavathi Krishnasamy
Medical hypothesis, discovery & innovation in optometry, Vol. 7 No. 1 (2026), 27 May 2026 , Page 23-30
https://doi.org/10.51329/mehdioptometry242
Background: University students are increasingly exposed to prolonged digital device use for academic activities, which places them at risk of digital eye strain (DES). While prevalence is widely reported, limited attention has been given to awareness and preventive practices of students. This study aimed to determine the prevalence of DES, associated behavioral patterns, and preventive practices among university students.
Methods: A descriptive cross-sectional study was conducted during the Spring semester of the 2025–2026 academic year at the University of Buraimi, Oman. Using stratified random sampling, 240 undergraduate students were recruited from all four colleges. Data were collected through an online survey comprising demographic characteristics, digital device usage habits, the validated Computer Vision Syndrome Questionnaire (CVS-Q), and items assessing awareness and preventive practices.
Results: Overall, 58.8% (n = 141) of participants were classified as having DES, with the majority experiencing mild symptoms (n = 89, 37.1%), followed by moderate (n = 40, 16.7%) and severe (n = 12, 5.0%) symptoms. The most commonly reported symptoms were tearing (n = 137, 57.1%), ocular dryness (n = 125, 52.1%), eye redness (n = 115, 47.9%), burning sensation (n = 104, 43.3%), and itching (n = 104, 43.3%). Prolonged screen exposure was common, with 72.5% (n = 174) reporting 5 hours or more of daily use, alongside frequent use of multiple devices and suboptimal ergonomic practices, including close viewing distances and poor posture. Awareness of DES was reported by 37% (n = 87) of participants, yet adoption of preventive practices was inconsistent. A statistically significant association was observed between engagement in preventive practices and lower DES severity (P < 0.05), whereas awareness alone was not significantly associated with symptom severity (P > 0.05).
Conclusions: The findings of this study indicate a 58.8% prevalence of DES among Omani university students. Prolonged screen time emerged as a key predictive factor. Awareness of DES was limited, and adherence to preventive practices remained low. These results underscore the need for targeted educational interventions on eye health, emphasizing simple and effective strategies such as the 20-20-20 rule to reduce the burden of DES among university students.
Impact of artificial tear viscosity and timing on keratometric measurements in cataract patients with and without dry eye disease: a randomized cross-over study
Eman Mohamed Yousef Elsadek, Younis Saeed Abdel Hafez, Ehab Mahmoud Ghoneim
Medical hypothesis, discovery & innovation in optometry, Vol. 7 No. 1 (2026), 27 May 2026 , Page 31-40
https://doi.org/10.51329/mehdioptometry243
Background: Accurate keratometric assessment is essential for precise intraocular lens (IOL) power calculation in cataract surgery. Artificial tears are commonly used to optimize the ocular surface, yet their short-term effects on keratometric and biometric measurements remain uncertain. This study evaluated the impact of artificial tears with different viscosities on keratometry and optical biometry parameters in cataract patients with and without dry eye disease (DED).
Methods: This prospective, randomized cross-over study included 40 cataract patients (20 with DED and 20 with normal ocular surfaces). Each participant received high- and low-viscosity artificial tears on separate visits. Keratometric parameters (K1, K2), axial length (AL), anterior chamber depth (ACD), and calculated IOL power were measured using optical biometry at baseline and at 30 s, 2 min, and 5 min after drop instillation.
Results: Participants with DED were significantly older than those with normal ocular surfaces (P < 0.05), while sex distribution and intraocular pressure were comparable between groups (both P > 0.05). Both formulations induced significant transient changes in keratometric measurements, most evident at 30 s and 2 min post-instillation, with stabilization by 5 min (within-group P < 0.05). These fluctuations were more pronounced in eyes with DED, particularly with high-viscosity drops, which showed large within-subject effect sizes. No significant differences in K1 or K2 were observed between groups at post-instillation timepoints (all P > 0.05). AL and ACD remained stable across all groups and timepoints (all P > 0.05). A modest but statistically significant reduction in calculated IOL power was observed only in DED eyes receiving high-viscosity artificial tears (P < 0.05).
Conclusions: Artificial tears induce transient alterations in keratometric measurements, particularly within the first 2 min after instillation and in eyes with tear film instability. High-viscosity formulations exert more pronounced effects and may influence IOL power calculations. To ensure accurate optical biometry, keratometry should be deferred for at least 5 min following artificial tear instillation, especially in patients with DED.
Developing a compact machine learning-based predictor for detecting above-mild ocular surface disease index scores
Nur Shazwani Mohd Gharib, Mohd Zulfaezal Bin Che Azemin, Noor Ezailina Badarudin, Muhammad Afzam Shah Abdul Rahim, Sharon Viola Shanthini, Mohammed Aljarousha
Medical hypothesis, discovery & innovation in optometry, Vol. 7 No. 1 (2026), 27 May 2026 , Page 41-49
https://doi.org/10.51329/mehdioptometry244
Background: The 12-item Ocular Surface Disease Index (OSDI) is widely used to assess dry eye disease (DED) severity; however, its length may reduce patient compliance and clinical efficiency. Given the expanding role of machine learning in ophthalmology, we aimed to develop and validate a compact OSDI predictor using supervised machine learning techniques to improve the efficiency and accuracy of DED assessment.
Methods: This retrospective study analyzed a dataset of complete 12-item OSDI questionnaires obtained from adult residents of the Gaza Strip. OSDI scores were recalculated using the standard scoring formula, with not applicable responses treated as missing and excluded from the denominator. Participants were categorized as having moderate-to-severe dry eye (OSDI > 22) or not. Three supervised machine learning models; decision tree, support vector machine, and logistic regression, were developed using Python. Binary feature-importance analysis was initially performed using the full 12-item OSDI, after which each model was retrained using only questionnaire items with a binary feature-importance value of 1. Model performance was evaluated using accuracy, sensitivity, specificity, and precision.
Results: Among 452 participants (mean [standard deviation] age, 32.0 [11.8] years; 52.9% male), 252 (55.8%) were classified as having moderate-to-severe dry eye, 200 (44.2%) were not. In the reduced-feature testing models, support vector machine model demonstrated the best overall performance, achieving 94.5% accuracy, 98.0% sensitivity, 90.0% specificity, and 92.6% precision. Logistic regression also showed strong performance, with 93.4% accuracy, 98.0% sensitivity, 87.5% specificity, and 90.9% precision. The decision tree model yielded lower testing accuracy (78.0%) and sensitivity (70.6%) but maintained relatively high specificity (87.5%) and precision (87.8%). Feature-importance analysis identified sensitivity to light, gritty sensation, computer or bank machine use, windy conditions, low-humidity environments, and air-conditioned places as informative predictors in the decision tree model. Both support vector machine and logistic regression models identified gritty sensation, painful or sore eyes, blurred vision, reading, watching television, and air-conditioned places as key predictors.
Conclusions: Supervised machine learning models, particularly support vector machine and logistic regression models, effectively classified moderate-to-severe dry eye using recalculated standard OSDI scores and reduced feature sets. The identified predictors underscore the importance of ocular discomfort, visual disturbance, sustained visual activities, and environmental triggers in DED symptom severity. These findings support the potential utility of machine learning-assisted tools for symptom-based DED screening and severity assessment. Further validation in independent clinical populations and integration with objective diagnostic measures are warranted.
Winter 2025
Vol. 6 No. 4 (2025)
Peripapillary retinal nerve fiber layer thickness and central macular thickness in children with anisometropia
Sara El Zeiny , Ehab M Ghoneim , Mohamed M Karrar
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 4 (2025), 30 January 2026 , Page 144-149
https://doi.org/10.51329/mehdioptometry233
Background: Anisometropia is associated with asymmetric ocular growth and may influence retinal structure, yet its impact on retinal nerve fiber layer thickness (RNFLT) remains incompletely understood. This study aimed to evaluate RNFLT and central macular thickness (CMT) in children with anisometropia and to examine their relationships with refractive error and ocular biometric parameters.
Methods: This cross-sectional study included children aged 5–16 years with anisometropia. Comprehensive ophthalmic evaluation included cycloplegic refraction, ocular biometry, and spectral-domain optical coherence tomography. Peripapillary RNFLT and CMT were measured and compared between worse and fellow eyes, as well as between amblyopic and non-amblyopic eyes. Correlations between spherical equivalent refraction (SER) and ocular parameters, including axial length, intraocular pressure, CMT, and RNFLT, were assessed.
Results: Among 46 children (median age 14 years), 45.7% (n = 21) had anisometropic amblyopia. Nasal RNFLT was significantly greater in worse eyes compared with fellow eyes (P < 0.05), while other quadrants and CMT showed no significant interocular differences. Amblyopic eyes showed higher RNFLT values than non-amblyopic eyes, reaching significance only in the nasal quadrant. SER showed a strong negative correlation with axial length (r = -0.91, P < 0.001) and moderate or weak positive correlations with quadrant-specific RNFLT, including inferior (r = +0.56, P = 0.001), superior (r = +0.67, P < 0.001), temporal (r = +0.59, P < 0.001), and nasal (r = +0.37, P = 0.012) quadrants, but not with CMT (r = -0.22, P > 0.05) or IOP (r = +0.19, P > 0.05).
Conclusions: Children with anisometropia exhibit selective regional RNFLT alterations, particularly involving the nasal quadrant, while macular thickness remains largely preserved. The observed associations between refractive error, AL, and RNFLT suggest that anisometropia may influence retinal structural development in a region-specific manner. Longitudinal studies are warranted to clarify the temporal relationship between refractive asymmetry and retinal structural remodeling.
Chi-square test applications
Parisa Ataee Dizaji , Fatemeh Heidary, Reza Gharebaghi
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 4 (2025), 30 January 2026 , Page 150-159
https://doi.org/10.51329/mehdioptometry234
Background: The chi-squared (x²) test is a fundamental non-parametric statistical method. It is widely employed in clinical, epidemiological, and biomedical research, including ophthalmology and optometry. It is useful for testing hypotheses regarding the independence of categorical data or the goodness-of-fit of the observed data to the expected distributions within contingency tables. In this review, we present a thorough examination of the statistical principles and clinical relevance of the x² test, focusing on its application in vision science and related research domains.
Methods: We outline the conceptual framework and methodological steps for conducting the x² test, emphasizing its two primary forms: the goodness-of-fit test and the test of independence. We discuss key assumptions, such as the independence of observations, use of frequency data, and minimum expected cell counts in detail. Moreover, we explain the process of calculating degrees of freedom (df) and interpreting results based on critical values from the x² distribution. Additionally, appropriate measures of effect size, i.e., Phi for 2 × 2 tables and Cramer’s V for larger tables, for assessing association strength, are introduced. To contextualize its clinical relevance, we present four examples from ophthalmology.
Results: In the first example, the association between vision impairment (VI) and sex was examined using a 2 × 6 contingency table. The x² statistic was 4.37 with 5 df (P > 0.05), indicating no statistically significant association. Cramer’s V was 0.04, suggesting a very weak effect. The second example tested the association between age category and first-year persistence with antiglaucoma therapy. Here, x² = 5.93 (df = 2, P > 0.05), also showing no significant association, Cramer’s V was weak (0.04). In the third example, a 2 × 2 table was used to analyze the association between sex and the type of anti-vascular endothelial growth factor injection (aflibercept or ranibizumab) used. This yielded a x² = 0.214 (df = 1, P > 0.05) and phi = 0.05, again indicating no statistically significant association and a weak effect. In a goodness-of-fit test assessing the pattern of contact lens usage, the x² exceeded the critical threshold, indicating a significant deviation between the observed and expected frequencies, leading to rejection of the null hypothesis.
Conclusions: The x² test is a robust tool for analyzing categorical data, enabling clinicians and researchers to identify potential relationships between variables. However, its reliability depends on its proper application, including verification of assumptions and appropriate interpretation of effect sizes, along with consideration of statistical significance. In clinical disciplines, such as ophthalmology or optometry, understanding and utilizing the x² test enhances research rigor and the validity of research findings, facilitating better-informed decisions in patient care and in program development.
Contact lens procurement practices and wear habits among users in Oman
Maryam Darwish Al-Ghaithi , Mithaa Mohammed Al-Esaei , Maroa Khamis Al-Qasmi , Kawthar Salim Al-Buraiki , Babu Noushad
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 4 (2025), 30 January 2026 , Page 160-165
https://doi.org/10.51329/mehdioptometry235
Background: Contact lens wear is widely preferred for refractive error correction because of its cosmetic appeal and visual benefits. However, safe use requires adherence to proper prescription, wear, and maintenance practices. Non-compliance increases the risk of complications, particularly when contact lenses are procured from non-conventional sources. Despite contact lens wear being a major risk factor for microbial keratitis, data on contact lens procurement and wear habits in Oman remain limited.
Methods: This descriptive cross-sectional study employed non-probability sampling using a self-administered questionnaire conducted between January and April 2024. Participants were 18 years or older, resided in Oman, and reported contact lens use. The survey assessed contact lens procurement, wear patterns, care practices, and compliance with recommended lens care behaviors.
Results: A total of 526 individuals participated, with a mean (standard deviation) age of 23.7 (6.1) years (range: 18–53), representing all governorates of Oman. The majority were female (n = 484, 92.0%) and students (n = 336, 64.0%). Nearly half of participants (n = 259, 49.2%) used contact lenses for cosmetic purposes. While 68.4% (n = 360) wore soft contact lenses, 24.9% (n = 131) were unaware of the type of lenses they used. Approximately 60% (n = 316) of participants did not undergo an eye examination prior to obtaining their first pair of contact lenses; 22.2% (n = 117) purchased lenses online, and 16.2% (n = 85) from pharmacies or beauty salons without specialist consultation. Furthermore, 68.1% (n = 358) did not have regular eye examinations and 18.4% (n = 97) reported sharing contact lenses with friends.
Conclusions: Contact lens use is common among young people in Oman, predominantly for cosmetic purposes, and unsafe practices are widespread. Non-conventional procurement, lack of eye examinations, missed follow-up visits, and contact lens sharing were frequently reported. These findings underscore the need for stricter regulation of contact lens distribution and targeted public health education to promote safe contact lens wear. Future research should use nationally representative samples to further evaluate contact lens safety practices in Oman.
Pattern of ocular injury in pediatric patients visiting a tertiary eye hospital in Eastern Nepal
Rajendra Mehta , Sanjay Kumar Sah , Pankaj Ray Adhikari , Pradeep Kumar Patel , Rajiv Ranjan Karn
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 4 (2025), 30 January 2026 , Page 166-173
https://doi.org/10.51329/mehdioptometry236
Background: Pediatric ocular trauma is a leading cause of preventable visual morbidity and monocular blindness worldwide. The epidemiology and clinical patterns of ocular injuries vary across regions due to differences in environmental exposure, socioeconomic factors, and supervision practices. Understanding local injury patterns is essential to informing targeted prevention strategies and optimizing clinical management.
Methods: A hospital-based cross-sectional observational study was conducted at Biratnagar Eye Hospital, a tertiary eye care center in Eastern Nepal, between April and September 2023. Pediatric patients younger than 16 years presenting for the first time with ocular trauma were consecutively enrolled. Data on demographic characteristics, educational status, causative agents, place and anatomical zone of injury, clinical diagnosis, and management approach were collected using a structured proforma. Injuries were categorized based on anatomical zones, and management was classified as medical, surgical, or observational. Results were summarized using descriptive statistics.
Results: A total of 260 children were included, 184 (70.8%) of whom were male. The highest incidence of ocular trauma was observed in children aged 6–10 years (n = 115, 44.2%). Stick- or wood-related injuries were the most common cause (n = 85, 32.7%), followed by injuries from iron or other sharp objects (n = 45, 17.3%). The majority of injuries occurred at home (n = 170, 65.4%). Open globe injuries constituted the most frequent diagnosis (n = 101, 38.8%), while Zone I injuries accounted for 96.9% (n = 252) of cases, indicating predominant anterior segment involvement. Medical management alone was sufficient in 58.0% (n = 150) of patients, whereas 40.0% (n = 104) required surgical intervention.
Conclusions: Pediatric ocular trauma in Eastern Nepal predominantly affects school-aged boys and frequently occurs in the home environment due to largely preventable causes. The substantial burden of open globe and anterior segment injuries highlights the need for strengthened injury prevention strategies, enhanced parental supervision, and timely access to specialized ophthalmic care. Targeted community education and coordinated trauma management approaches may help reduce the incidence and visual consequences of pediatric ocular injuries.
Normative values for near point of convergence among university students in Oman
Mitha Abdul Hamid Al Shehhi , Thara Salim Bait Kura, Zoelfigar Dafalla Mohamed
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 4 (2025), 30 January 2026 , Page 174-180
https://doi.org/10.51329/mehdioptometry237
Background: Near point of convergence (NPC) is a key clinical measure used in the assessment of binocular vision function and the diagnosis of convergence insufficiency. Normative NPC values vary across populations and are influenced by demographic and methodological factors. However, population-specific normative data for NPC are lacking in Oman. This study aimed to establish normative NPC break and recovery values among emmetropic university students in Oman and to examine variations by sex and age.
Methods: This prospective cross-sectional study was conducted among students at the University of Buraimi, Oman. Emmetropic participants aged 17–25 with best-corrected distance visual acuity 20/20 or better, near visual acuity N6, normal binocular vision, and a Convergence Insufficiency Symptom Survey (CISS) score less than or equal to 21 were included. NPC break and recovery points were measured subjectively using a standardized Royal Air Force (RAF) ruler with an accommodative target. Three consecutive measurements were obtained for each parameter, and mean values were recorded. Descriptive statistics were calculated, and comparisons by sex and age group were performed using independent-samples t-tests and one-way analysis of variance, respectively.
Results: A total of 350 participants (74.9% female) met the inclusion criteria, with a mean (standard deviation [SD]) age of 20.16 (1.78) years. The overall mean (SD) NPC break point was 10.0 (2.6) cm (95% confidence interval [CI]: 9.7–10.3 cm) and the mean (SD) recovery point was 12.0 (2.0) cm (95% CI: 11.8–12.2 cm). Mean (SD) CISS score was 11.3 (6.3) (95% CI: 10.6–11.9), indicating a largely asymptomatic cohort. Females showed significantly more remote NPC break and recovery points than males (break: 10.2 vs 9.4 cm, P < 0.05; recovery: 12.2 vs 11.5 cm, P < 0.05). No statistically significant differences in NPC break or recovery values were observed across age groups (17–19, 20–22, and 23–25 years; P > 0.05).
Conclusions: This study provides the first population-specific normative NPC break and recovery values for young adults in Oman using a standardized RAF ruler method. NPC measurements were influenced by sex but not by age within the examined range, reflecting the relative stability of convergence function in young adulthood. These findings offer clinically relevant reference values for optometric practice in Oman, underscoring the importance of establishing population- and context-specific normative data to enhance the assessment and management of binocular vision disorders.
Sight-threatening ocular manifestations in the post-coronavirus pandemic era
Srinivasan Sanjay , Deepashri Mutalik, Balughatta Poornachandra, Vijay KR Rao , Balu Ramgopal, Ankush Kawali, Padmamalini Mahendradas
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 4 (2025), 30 January 2026 , Page 181-195
https://doi.org/10.51329/mehdioptometry238
Background: Coronavirus disease (COVID-19) infection can be associated with post-recovery sight-threatening complications like optic neuritis, retinal vascular occlusions, endophthalmitis, and panophthalmitis. This study was conducted to explore the various sight-threatening post-COVID-19 ophthalmic manifestations.
Methods: This retrospective observational case series included seven patients who were diagnosed with sight-threatening manifestations post-COVID-19. They underwent detailed ophthalmic and systemic evaluation, including laboratory investigations for systemic hypercoagulable and inflammatory markers.
Results: Seven Indian patients (6 males:1 female, age range 37–66 years) presented to us with severe eye pain, acute loss of vision, redness, and watering after being diagnosed and treated for COVID-19 infection. The time from COVID-19 diagnosis to ocular sampling was 14–60 days (median 27), that of ocular symptoms to ocular sampling 1–50 days (median 4). Visual acuity ranged from no perception of light to 20/36. Three patients were pre-existing diabetics, two developed diabetes during their COVID-19 treatment. Diagnosis included one case of central retinal artery occlusion, one case of vitreous hemorrhage with retinal vasculitis, two cases of presumed bacterial endogenous endophthalmitis, one case of presumed fungal endophthalmitis, and two cases of panophthalmitis, one of them bilateral. Patients with infective intraocular inflammation were subjected to blood, ocular specimens, and urine cultures, which yielded growth in some patients. PCR of ocular specimens were positive for panfungal and/or eubacterial genome. Treatment included oral and systemic antimicrobial therapy with or without systemic steroids, with intravitreal antibiotics and/or steroids in selected cases. Final visual outcome ranged from no perception of light to 20/20.
Conclusions: Patients in this group had both vascular occlusions and infection as a cause of sight-threatening visual loss. Functional visual outcome may not be achieved in this diverse group of patients. Multi-specialty management was required in most of the cases. Larger prospective studies with controls are required to clarify pathogenesis, optimal screening, and management strategies for post-COVID-19 ocular complications.
Fall 2025
Vol. 6 No. 3 (2025)
Blunt facial trauma as a predictor of ocular injury in polytrauma patients: a cross-sectional study
Aziz Rasooli , Mohammad Sedaghat , Meisam Sharifi, Mahdi Ebrahimi, Mohammad Vaseie
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 3 (2025), 21 November 2025 , Page 86-91
https://doi.org/10.51329/mehdioptometry227
Background: Ocular injury is a clinically significant complication of facial trauma, yet its burden and predictors in polytrauma remain undercharacterized. Understanding these associations is essential for optimizing early ophthalmic assessment, particularly in settings with high rates of road traffic injuries.
Methods: This retrospective cross-sectional study included polytrauma patients (injury severity score [ISS] >15) admitted to a tertiary trauma center over a five-year period. Eligible patients sustained blunt injuries and underwent standardized craniofacial CT and ophthalmic assessment. Facial trauma was identified using International Classification of Diseases, Tenth Revision (ICD-10) codes and radiologic confirmation. Ocular injuries were classified according to Birmingham Eye Trauma Terminology System criteria. Data on demographics, injury mechanisms, and clinical findings were extracted for analysis.
Results: Among 7456 polytrauma patients (mean age 38.7 years), 68.2% (5085) were male and 1491 (20.0%) had blunt facial trauma. Ocular injury occurred in 20.9% (n = 312) of patients with facial trauma versus 4.2% (n = 251) without. Midface fractures were strongly associated with orbital injury, whereas mandibular fractures were associated with ocular adnexal trauma (both P < 0.001). The most frequent ocular findings were orbital fracture (n = 312/142, 45.5%), subconjunctival hemorrhage (n = 312/88, 28.2%), hyphema (n = 312/46, 14.7%), and globe rupture (n = 312/12, 3.8%). Subgroup analyses further demonstrated that road traffic accidents (RTAs) mechanism conferred more than twice the risk of ocular injury compared with other mechanisms. Multivariate logistic regression analysis identified blunt facial trauma (adjusted odds ratio [OR], 3.82; 95% confidence interval [CI], 2.91–5.02; P < 0.001), RTAs (adjusted OR, 2.14; 95% CI, 1.67–2.75; P < 0.001), male sex (adjusted OR, 1.45; 95% CI, 1.12–1.88; P = 0.005), higher ISS (adjusted OR, 1.06 per point; CI, 95%, 1.03–1.09; P < 0.001), and increasing age (adjusted OR, 1.02 per year; 95% CI, 1.00–1.04; P < 0.005) as independent predictors of ocular injury. Baseline visual impairment (VA < 20/40) was present in 38.2% of affected patients. The incidence of facial trauma showed a slight upward trend from 2021 to 2025, albeit not statistically significant (P > 0.05).
Conclusions: Ocular injury represents a substantial and clinically important component of polytrauma involving the face. Patients with blunt facial trauma, particularly those with RTAs mechanisms, are at markedly elevated risk of ocular injury. Age, sex, fracture pattern, injury mechanism, and overall trauma severity are key determinants of ocular morbidity, underscoring the need for integrated maxillofacial-ophthalmic management strategies within trauma care systems.
Six-month longitudinal analysis of visual, tomographic, and densitometric changes after corneal collagen cross-linking in keratoconus
Ezgi Karatas, Seher Koksaldi , Canan Asli Utine
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 3 (2025), 21 November 2025 , Page 92-103
https://doi.org/10.51329/mehdioptometry228
Background: Keratoconus is a progressive corneal ectasia commonly treated with corneal collagen cross-linking (CXL) to halt further progression. Although transient anterior stromal haze frequently develops after CXL, its impact on visual recovery remains unclear. This study aimed to examine the correlation between postoperative changes in corneal densitometry, visual acuity, topography, and pachymetry in eyes with keratoconus undergoing CXL.
Methods: This retrospective study included eyes with progressive keratoconus undergoing epithelium-off accelerated CXL. Pre- and postoperative assessments included measuring corrected distance visual acuity (CDVA), manifest refraction, and slit-lamp biomicroscopy examination, along with Pentacam HR imaging. Densitometry was quantified across three stromal depths and four annular zones. Follow-up evaluations were performed at day 1, week 1, and months 1, 3, and 6 post-CXL.
Results: Twenty-four eyes from 24 patients with progressive keratoconus (median age, 21.9 years; 79.2% male) were evaluated over a six-month period following CXL. At six months significant improvements were observed in CDVA, accompanied by reductions in flat keratometry, central corneal thickness, and thinnest pachymetry (all P < 0.05). Corneal densitometry increased significantly at one month and partially regressed by six months across all stromal depths and within all concentric annular zones from 0.0–2.0 mm to 6.0–10.0 mm and their corresponding total values (all P < 0.05). Baseline anterior 0.0–2.0 mm densitometry demonstrated a significant inverse correlation with CDVA (r = –0.50, P < 0.05). At one month, CDVA correlated inversely with anterior (r = –0.47, P = 0.003) and mid-stromal (r = –0.58, P = 0.006) 0.0–2.0 mm densitometry, and with anterior 2.0–6.0 mm densitometry (r = –0.45, P = 0.045). By six months, no significant correlations were found between CDVA or absolute keratometric parameters and densitometry at any depth, zone, or total value (all P > 0.05), indicating stabilization of both visual and structural recovery.
Conclusions: Accelerated epithelium-off CXL yielded significant visual and structural improvements in progressive keratoconus over six months. Corneal densitometry followed a characteristic postoperative pattern, with an early peak at one month followed by partial regression. Early stromal backscatter increases were significantly correlated with visual acuity, but these relationships diminished by six months, consistent with recovery of corneal clarity and vision. Longer-term studies are warranted to clarify the prognostic utility of densitometry for visual and tomographic outcomes after CXL.
Structural and microvascular retinal changes in keratoconus: an OCT and OCT angiography study
Ozlem Ozkan , Canan Asli Utine , Raffaele Piscopo, Luca D Andrea
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 3 (2025), 21 November 2025 , Page 104-111
https://doi.org/10.51329/mehdioptometry229
Background: Keratoconus is increasingly recognized as a condition that may affect not only corneal structure but also posterior segment parameters. This study aimed to evaluate alterations in central macular, choroidal, and peripapillary retinal nerve fiber layer thicknesses, as well as peripapillary vessel densities (VDs), in eyes with keratoconus using optical coherence tomography (OCT) and OCT angiography (OCTA).
Methods: This cross-sectional study included eyes with keratoconus and healthy control eyes. Participants underwent Scheimpflug corneal tomography (Pentacam HR) to assess central corneal thickness (CCT) and keratometry; spectral-domain OCT (SD-OCT) for central macular thickness (CMT), choroidal thickness, and peripapillary retinal nerve fiber layer thickness (RNFLT) measurements; and swept-source OCT angiography (SS-OCTA) to quantify peripapillary VD centrally and across four quadrants at the superficial and deep capillary plexuses (pSCP, pDCP), the peripapillary choriocapillaris (pCC), and the global radial peripapillary capillary plexus (nRPCP).
Results: Eighty-six eyes with keratoconus and 86 age-, sex-, axial-length-, and laterality-matched healthy controls (all P > 0.05) were analyzed. The keratoconus group showed significantly higher spherical equivalent, higher keratometry parameters, higher astigmatism, and lower CCT, along with worse best-corrected distance visual acuity (all P < 0.001). Mean choroidal thickness was significantly greater in eyes with keratoconus (P < 0.001), whereas CMT, global RNFLT, and most quadrant RNFLT measures were comparable (all P > 0.05), except for a thinner inferonasal RNFLT (P < 0.05). Central VD in the pSCP, pDCP, pCC, and global nRPCP were significantly reduced (all P < 0.05). Eyes with keratoconus additionally demonstrated a non-significant (all P > 0.05) but characteristic pattern of regional VD alterations across peripapillary sectors.
Conclusions: Keratoconus was associated with significant microvascular and structural alterations extending beyond the cornea, including reduced VDs in central peripapillary plexuses, localized thinning of inferonasal RNFL, and increased choroidal thickness. These findings support a broader pathophysiologic framework in which keratoconus involves not only anterior corneal remodeling but also measurable changes in blood supply within the macular and lamina cribrosa regions. The characteristic, though nonsignificant, regional VD patterns further underscore potential sectoral vulnerability. Future longitudinal and multimodal imaging studies are warranted to clarify the temporal evolution, clinical relevance, and prognostic utility of these microvascular changes in keratoconus.
Prevalence and demographic characteristics of strabismus in adults
Kourosh Shahraki , Abolfazl Tahkor , Fariba Shahraki-Sanavi , Kianoush Shahraki, Hasan Okati-Aliabad, Mahdi Mohammadi , Alireza Ansari-Moghaddam
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 3 (2025), 21 November 2025 , Page 112-120
https://doi.org/10.51329/mehdioptometry230
Background: Strabismus is a common ocular disorder and a major cause of visual impairment and amblyopia. Its prevalence varies widely across populations and may differ by age, ethnicity, and underlying risk factors. Despite its clinical and psychosocial impact, data on strabismus in Iranian adults remain limited. This study aimed to determine the prevalence of strabismus and its associated demographic factors in southeastern Iran.
Methods: This cross-sectional analysis used baseline data from an adult eye cohort in Zahedan, southeastern Iran. A stratified cluster sampling design, based on socioeconomic status, was used to recruit residents aged 35–70 years between 2015 and 2019. Of 10 016 screened individuals, 9296 met inclusion criteria of Iranian nationality, greater than or equal 9 months of local residency, and completion of baseline assessments; participants with prior ocular surgery or active ocular disease were excluded. All participants completed a standardized ocular history questionnaire and underwent comprehensive visual assessment, including Snellen visual acuity testing, objective and subjective non-cycloplegic refraction, automated lensometry for habitual correction, external examination, slit-lamp biomicroscopy, and Goldmann applanation tonometry. Ocular alignment was evaluated using cover-uncover and alternate cover tests at distance and near vision. Strabismus was classified based on manifest deviations detected under best correction.
Results: Among 9296 adults, the overall prevalence of strabismus was 2.8% (262 cases; 95% CI: 2.5–3.2). The prevalences of exotropia, esotropia, hypertropia, intermittent exotropia, and intermittent esotropia were 1.3% (129 cases, 95% CI: 0.00–3.20), 0.2% (18 cases, 95% CI: 0.00–2.20), 0.3% (26 cases, 95% CI: 0.00–2.40), 0.8% (77 cases, 95% CI: 0.00–2.70), and 0.1% (12 cases, 95% CI: 0.00–1.80), respectively. Strabismus occurred most frequently in the 45–54-years age group (n = 92, 35.1%) and least often in those aged 65–75 years (n = 14, 8.3%). Women accounted for 61.8% (n = 162) of all cases, with all subtypes more common in women except for esotropia, which was equally distributed. Strabismus was most frequent among individuals with high school education (n = 89, 34.0%) and least common in those with university degrees (n = 46, 17.6%). The Sistani ethnic group showed the highest prevalence (n = 141, 53.8%) across all subtypes.
Conclusions: Strabismus affected 2.8% of adults, with exotropia the most common subtype. Prevalence varied by age, sex, educational level, and ethnicity, with the highest burden in adults aged 45–54 years and among the Sistani group. Most cases were previously undiagnosed, underscoring the need for targeted screening and early detection. Ongoing longitudinal follow-up will clarify incidence, progression, and treatment outcomes, supporting improved clinical decision-making, resource allocation, and long-term visual outcomes.
Persistent corneal epithelial defects: an updated review of literature
Kimia Kazemzadeh
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 3 (2025), 21 November 2025 , Page 121-128
https://doi.org/10.51329/mehdioptometry231
Background: Persistent corneal epithelial defects (PCEDs) represent a significant clinical challenge characterized by the failure of the corneal epithelium to heal within the normal period, leading to potential sight-threatening complications. These defects arise from a variety of underlying etiologies, including limbal stem cell deficiency, neurotrophic keratopathy, dry eye syndrome, and systemic diseases such as diabetes mellitus. Despite advances in ophthalmic care, PCEDs remain difficult to treat due to diverse pathophysiological mechanisms and variable response to conventional therapies. Recent developments in growth factor therapies, biological treatments, surgical techniques, and regenerative medicine have expanded therapeutic options but necessitate comprehensive review to guide clinical practice.
Methods: A comprehensive narrative review was conducted through a systematic search of major electronic databases including PubMed/MEDLINE, Embase, Scopus, and Google Scholar. The search incorporated keywords and Medical Subject Headings related to “persistent corneal epithelial defects”, “corneal epithelial healing”, “limbal stem cell deficiency”, “neurotrophic keratopathy”, “amniotic membrane transplantation”, and “emerging treatments”. Peer-reviewed original studies, clinical trials, reviews, and meta-analyses published between 1 January 2000 and 31 March 2025 were included. Articles were critically appraised and selected according to their relevance, methodological quality, and contribution to understanding PCED pathophysiology, diagnosis, and treatment advancements.
Results: The review delineates the anatomy and physiological roles of the corneal epithelium, highlighting mechanisms that lead to epithelial defect persistence, including impaired basement membrane integrity, stem cell deficiency, inflammation, and neurotrophic factors. Clinical presentation and diagnostic modalities such as fluorescein staining and advanced imaging techniques are discussed. Standard management with lubricants, therapeutic contact lenses, infection control, and autologous serum eye drops is described, alongside medical therapies targeting epithelial regeneration, including recombinant human nerve growth factor and platelet-rich plasma. Surgical interventions like amniotic membrane transplantation and novel regenerative approaches involving stem cell therapy and corneal neurotization show promising results in refractory cases. Emerging molecular therapies and bioengineered drug delivery systems represent the forefront of innovation in PCED treatment.
Conclusion: PCEDs pose complex therapeutic challenges necessitating a multifaceted treatment approach. Advances in molecular, cellular, and surgical therapies have substantially expanded management options and improved healing outcomes. However, continued research into personalized therapies, optimization of delivery methods, and long-term safety is essential. This review provides a comprehensive synthesis of current knowledge and emerging trends to inform clinicians and researchers in the effective management of PCEDs, ultimately aiming to preserve vision and enhance quality of life. Future research should focus on minimally invasive sustained-release therapies, biomarker-guided personalized interventions, and combination approaches targeting epithelium, inflammation, and nerves.
Pregnancy-related retinal disorders: clinical features, systemic associations, and management insights
Pegah Rashidian, Sepide Ahmadi , Kyana Jafarabady, Arman Shafiee, Mohammadamin Noorafrooz, Ehsan Amini-Salehi , Sedigheh Hantoushzadeh
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 3 (2025), 21 November 2025 , Page 129-143
https://doi.org/10.51329/mehdioptometry232
Background: Pregnancy induces profound hormonal, hemodynamic, and metabolic changes that can trigger or exacerbate retinal disorders, some of which may signal systemic complications. This narrative review summarizes current knowledge on retinal diseases specifically induced or worsened during pregnancy.
Methods: A comprehensive literature search was conducted in PubMed/MEDLINE, Embase, Web of Science, and Google Scholar up to 31 September 2025, supplemented by manual screening of reference lists of included records. Search terms included “pregnancy”, “preeclampsia”, “eclampsia”, “HELLP syndrome”, “hemolysis, elevated liver enzyme levels, and low platelets syndrome”, “retinal disease”, “retinopathy”, “hypertensive retinopathy”, “serous retinal detachment”, “central serous chorioretinopathy”, “diabetic retinopathy”, “Valsalva retinopathy”, “retinal vein occlusion”, “retinal artery occlusion”, “idiopathic intracranial hypertension”, and “artificial intelligence”. Eligible articles included case reports, case series, observational studies, reviews, and meta-analyses describing retinal conditions specifically induced or worsened during pregnancy. Data were synthesized narratively.
Results: Pregnancy can precipitate sight-threatening retinal pathology or accelerate pre-existing disease. Hypertensive retinopathy associated with preeclampsia and eclampsia is among the most clinically significant conditions, presenting with arteriolar narrowing, retinal hemorrhages, cotton-wool spots, and, in severe cases, serous retinal detachment. Metabolic adaptations, particularly in women with pregestational diabetes, may accelerate the progression of diabetic retinopathy, with some patients advancing from nonproliferative to proliferative stages over short intervals. Pregnancy has also been implicated in serous retinal detachment, central serous chorioretinopathy, Valsalva retinopathy, retinal vascular occlusions, and, less commonly, papilledema secondary to idiopathic intracranial hypertension. These disorders range from transient, self-limited entities to sight-threatening events and often reflect systemic pathology, including preeclampsia, eclampsia, or hypercoagulable states. Optical coherence tomography, optical coherence tomography angiography, and fundus photography provide safe, noninvasive diagnostic and monitoring modalities. Artificial intelligence (AI)-based retinal imaging offers accurate, noninvasive assessment of diabetic and hypertensive retinopathy and demonstrates expert-level performance across clinical settings. Management emphasizes stabilization of maternal systemic disease, optimization of glycemic and blood pressure control, and multidisciplinary care. Most conditions improve postpartum, but prompt recognition is essential to prevent permanent visual loss.
Conclusions: Pregnancy can precipitate or exacerbate a range of retinal disorders, reflecting the complex vascular, hormonal, and metabolic changes of gestation. Noninvasive imaging, interdisciplinary collaboration, and vigilant monitoring are essential to optimizing maternal and fetal outcomes. Awareness and early detection of pregnancy-associated retinal disorders, together with emerging AI-based tools, may further improve outcomes. Longitudinal studies are needed to establish evidence-based screening and management protocols.
Summer 2025
Vol. 6 No. 2 (2025)
Ocular dominance and refractive error: a cross-sectional study of 400 individuals at a tertiary eye hospital in eastern Nepal
Sanjay Kumar Sah, Sandip Das Sanyam, Pankaj Ray Adhikari, Rajiv Ranjan Karn
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 2 (2025), 31 July 2025 , Page 43-49
https://doi.org/10.51329/mehdioptometry221
Background: Ocular dominance is the consistent preference of using one eye over the other during visual processing, a phenomenon analogous to hand dominance. Ocular dominance often aligns with the eye delivering clearer vision, but does not always correspond to superior visual acuity or refractive status. Mechanisms underlying ocular dominance remain unclear, particularly in individuals whose refractive errors have remained uncorrected since childhood. In this study, we investigated ocular dominance patterns and their association with refractive error and handedness in individuals without early optical correction.
Methods: In this cross-sectional study, we recruited individuals aged 16–40 years with refractive errors, who had no history of spectacle use since childhood, from Biratnagar Eye Hospital, Nepal. Participants underwent anterior and posterior segment examinations using slit-lamp, followed by non-cycloplegic retinoscopy and subjective refraction. Ocular dominance was assessed using the Hole-in-the-Card (Dolman’s) and Miles tests. Hand dominance was determined through standardized questioning and observation during tasks. Spherical equivalents (SEQ) were calculated, and anisometropia was defined as an interocular refractive difference equal or greater than 1.00 D.
Results: Four hundred participants (mean [standard deviation, SD] age 26.1 [6.0] years; 61.3% males) were assessed for ocular and hand dominance. Refractive error SEQ ranged from +9.25 D to –13.50 D (mean [SD] –1.75 [2.46] D). Myopia was most common among students (n = 93, 23.3%) and least common among tailors (n = 14, 3.5%). The most frequent dominance pattern was right-hand combined with right-eye dominance (n = 328, 82%). A strong, statistically significant association was found between ocular and hand dominance (P < 0.01; Cramer’s V= 0.73). Moderate but statistically significant associations were observed between refractive error type and both ocular (P < 0.01; V = 0.25) and hand dominance (P < 0.01; V = 0.21). The dominant eye was not always the eye with better visual acuity. Among the 103 individuals with anisometropia (25.8%), ocular dominance was not consistently accompanied by either the higher refractive error or better visual acuity.
Conclusions: In this study, we demonstrated a strong and statistically significant association between ocular and hand dominance, suggesting existence of a significant lateralization pattern among individuals with refractive error who had no history of spectacle use since childhood. While a right-hand/right-eye dominance pattern was predominant, variations such as cross-dominance and absence of ocular dominance were also observed. A moderate but significant association was found between the type of refractive error and both ocular and hand dominance, indicating that visual and motor lateralization may influence refractive development. The dominant eye did not consistently accompany by better visual acuity or greater refractive error in individuals with anisometropia, underscoring the complexity of ocular dominance and its clinical implications. These findings may aid in understanding visual behavior and inform clinical decisions related to refractive surgeries, amblyopia management, and binocular vision assessments. Further research is needed to explore the underlying neurophysiological mechanisms.
Efficacy of Rose-K lens in enhancing visual acuity and contrast sensitivity in keratoconus
Hussain ALkhalasi , Zoelfigar Dafalla Mohamed
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 2 (2025), 31 July 2025 , Page 50-56
https://doi.org/10.51329/mehdioptometry222
Background: Keratoconus is a progressive, noninflammatory corneal ectasia that is characterized by corneal thinning and conical deformation, which leads to irregular astigmatism, myopia, and reduced visual quality. As the disease progresses, spectacles often become inadequate, necessitating the use of rigid gas-permeable or specialty contact lenses to restore vision. Traditional evaluations rely on high-contrast visual acuity tests, which alone do not capture functional vision impairments. A more comprehensive assessment includes contrast sensitivity (CS), a key predictor of real-world visual performance. The ROSE K2 XL semi-scleral lens offers tailored optical correction for irregular corneas. We investigated its efficacy in enhancing best-corrected distance visual acuity (BCDVA) and CS in patients with keratoconus.
Methods: In this prospective study, we recruited adults with varying keratoconus severities from the Armed Forces Hospital in Oman, between February and December 2024. The patients were fitted with ROSE K2 XL semi-scleral lenses to assess changes in BCDVA and CS. Participants who had undergone prior ocular surgery (except for corneal crosslinking) or who had other corneal pathologies were excluded. Baseline and post-fitting BCDVA were measured using a crowded Keeler logarithm of the minimum angle of resolution (logMAR) chart. CS was assessed using the Pelli–Robson chart under standardized photopic conditions. Keratoconus severity was graded using the Amsler–Krumeich classification system. All examinations were performed by the same experienced optometrist to ensure consistency and to reduce measurement variability.
Results: We enrolled 180 eyes from 90 participants with keratoconus (mean [standard deviation, SD] age: 29.2 [5.4] years; 65.6% [n = 59] female). Disease severity was classified as follows: stage I (n = 16, 8.9%), stage II (n = 52, 28.9%), stage III (n = 70, 38.9%), and stage IV (n = 42, 23.3%). After ROSE K2 XL lens fitting, the mean (SD) BCDVA improved significantly, from 0.90 (0.48) logMAR to 0.10 (0.11) logMAR (P < 0.001). The mean (SD) CS also increased significantly, from 0.96 (0.47) log CS to 1.90 (0.16) log CS (P < 0.001). Significant improvements in BCDVA and CS were observed across all disease stages (all P < 0.001), with the most pronounced gains found in cases of advanced keratoconus (stage IV).
Conclusions: Fitting ROSE K2 XL semi-scleral contact lenses in patients with keratoconus resulted in significant improvements in both BCDVA and CS across all disease severity levels. These findings show the clinical value of semi-scleral lenses for visual rehabilitation of keratoconus, particularly in the advanced stages, where conventional spectacles or lenses may offer limited benefits. Incorporating CS assessment with visual acuity evaluations provides a more comprehensive investigation of real-world visual function, supporting evidence-based lens selection to optimize patient outcomes. Future studies should explore the long-term effects of these lenses on corneal physiology and patient-reported quality of life.
Effect of adjunctive scleral buckling on the outcomes of pars plana vitrectomy in retinal detachment repair
Maryam Fatima, Amara Nasir, Zulkarnain Abbas, Syeda Seerat Zahra, Zunaira Nasir, Mehreen Muhammad Javed, Khushbakht Nasir
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 2 (2025), 31 July 2025 , Page 57-64
https://doi.org/10.51329/mehdioptometry223
Background: Rhegmatogenous retinal detachment (RRD) is a sight-threatening condition requiring prompt surgical repair. Pars plana vitrectomy (PPV) and scleral buckling (SB) are standard surgical interventions for RRD, but the added value of combining these treatments is debated. While PPV offers enhanced visualization and safety in complex RRD cases, SB may provide additional support in selected scenarios. However, the impact on functional outcomes, particularly contrast sensitivity (CS), remains unclear. In this study, we compared the anatomical success and visual function, including best-corrected distance visual acuity (BCDVA) and CS, between patients with primary RRD who were treated with PPV alone and those who were treated with combined PPV+SB.
Methods: This comparative cross-sectional study included consecutive patients with primary RRD who were treated at Madinah Teaching Hospital, Faisalabad, Pakistan, from October 2020 to July 2021. Participants underwent either 25-gauge PPV or 25-gauge PPV combined with SB, based on their clinical indications. BCDVA and CS were measured monocularly under standardized photopic conditions using the logarithm of the minimum angle of resolution (logMAR) visual acuity chart and the Pelli–Robson chart, respectively. Anatomical reattachment status was assessed by dilated fundus examination. Postoperative evaluations of BCDVA, CS, and anatomical reattachment rate were conducted at 1 day, 1 month, and 3 months after treatment.
Results: Ninety eyes of 90 patients with primary RRD were included (PPV: n = 45 eyes; PPV+SB: n = 45 eyes). The PPV group was approximately a decade younger (45.2 vs. 55.4 years, P < 0.05), while sex distribution was similar in both groups (P > 0.05). Anatomical success rates improved over 3 months, reaching 74.0% (n = 33) for PPV versus 62.2% (n = 28) for PPV+SB. PPV achieved significantly better final BCDVA (2.71 vs. 2.84 logMAR, P < 0.05). CS increased significantly over time in the PPV group (P < 0.05) but remained stable in the PPV+SB group (P > 0.05). Although the final CS was significantly higher in the PPV+SB group compared to the PPV group (P < 0.05), this difference reflected the higher baseline values in the former group. Overall, PPV alone provided greater anatomical and functional improvement over 3 months than did the combined surgery.
Conclusions: Standalone PPV achieved higher anatomical success rates and greater visual acuity improvement over 3 months than did combined PPV+SB, while CS gains favored PPV+SB, but largely reflected higher baseline values. Despite mixed evidence in the literature, our findings suggested that PPV alone may suffice for treating selected uncomplicated RRD cases. Further large, randomized studies are needed to clarify the optimal surgical approach across different patient and RRD profiles.
Outcomes of orthokeratology: a nine-year retrospective review from a university-based optometry clinic in Malaysia
Dawn Le Xuan Lah, Fakhruddin S. Barodawala
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 2 (2025), 31 July 2025 , Page 65-73
https://doi.org/10.51329/mehdioptometry224
Background: Orthokeratology (Ortho-K) is a non-surgical approach to myopia management that uses specially designed gas-permeable lenses to reshape the cornea temporarily and improve vision. While its efficacy is established, real-world data from diverse clinical settings remain limited. In this study we aimed to support evidence-based, individualized Ortho-K practice in routine optometric care by evaluating corneal and visual outcomes, lens designs, and treatment costs at a university-based optometry clinic in Malaysia.
Methods: In this retrospective study, we analyzed clinical records of individuals fitted with Ortho-K lenses at SEGi EyeCare, SEGi University, between January 2015 and October 2024. Eligible individuals were identified via electronic health records and included if they completed key follow-up visits at 1-night, 1–2-weeks, and 1–3-months post-dispensing. Exclusion criteria included incomplete records or missed follow-up visits. Data extracted included unaided distance visual acuity (UADVA) in logarithm of the minimum angle of resolution (logMAR), corneal topography (flat and steep keratometry, eccentricity), pupil size, treatment-zone diameter, age, lens design, and total treatment cost. Measurements were obtained using the Tomey TMS-5 topographer. For each patient, both eyes were analyzed independently.
Results: Data from 30 eyes of 15 patients (mean age and standard deviation [SD]: 23.3 [9.1] years) were analyzed. Significant improvements in corneal curvature and UADVA were observed across follow-up visits (all P < 0.05). Mean (SD) steep keratometry decreased from 43.79 (1.87) D to 42.08 (2.17) D, and flat keratometry from 42.40 (1.61) D to 40.59 (2.31) D at the final visit (both P < 0.05). UADVA improved from 0.93 (0.36) logMAR to 0.23 (0.24) logMAR (P < 0.05) at the final visit. Pupil size and treatment-zone diameter remained stable (both P > 0.05), indicating consistent lens centration. The mean (SD) Ortho-K cost per patient was RM 3736.67 (514.25), equal to USD 846.20.
Conclusions: Ortho-K treatment at this university-based optometry clinic significantly improved corneal curvature, refractive error, and UADVA, with most clinical changes stabilizing within the first month of lens wear. The stability of pupil size and treatment-zone diameter suggests consistent lens performance. These findings affirm the effectiveness of Ortho-K as a non-surgical option for myopia management in real-world practice. Future studies should incorporate axial length measurements and extended follow-up to validate treatment efficacy in slowing myopia progression.
Melatonin as a potential biomarker in diabetic retinopathy
Mahdi Abounoori, SeyedParsa Sajjadifar, Kimia Daneshvar, Mohsen Pourazizi
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 2 (2025), 31 July 2025 , Page 74-82
https://doi.org/10.51329/mehdioptometry225
Background: Diabetic retinopathy (DR) is a major complication of diabetes mellitus (DM). Melatonin protects against inflammation and oxidative stress. This review focuses on the literature comparing melatonin levels in patients with and without DR.
Methods: A thorough search of the PubMed/MEDLINE, Web of Science, and Embase databases was performed for articles published until April 2025. The inclusion criteria were studies reporting melatonin levels in patients with DR and control groups; studies involving human participants of any age, gender, or ethnicity; and investigations documented in scholarly publications. The exclusion criteria were as follows: animal studies; review articles; case reports; editorials; and conference abstracts; studies not available in English or lacking an English translation; and studies focusing on interventions altering melatonin levels rather than comparing levels between patients with DR and controls. Furthermore, we manually checked the reference lists of the included papers to identify any earlier series that were not initially found in our core search. The Newcastle-Ottawa Scale was used to evaluate study quality.
Results: Eight studies with 1004 participants published from 2011 to 2022 were included. The mean age of participants ranged from 39.9 to 72 years. Three studies assessed urinary melatonin excretion, three examined blood melatonin concentrations, one evaluated melatonin concentration in the aqueous humor, and one measured salivary melatonin levels. All samples were collected at night, except for three studies. All studies utilized enzyme-linked immunosorbent assay to measure melatonin concentration, except for the one study, which employed high-performance liquid chromatography. Numerous studies have indicated that patients with DM exhibit reduced melatonin levels relative to healthy controls, and that individuals with DR show lower levels than those without DR. Patients with proliferative DR exhibit reduced nocturnal urinary excretion of 6-sulfatoxymelatonin. Melatonin levels in the aqueous humor were elevated in patients with proliferative DR. Melatonin levels were negatively correlated with both the duration of DM and glycated hemoglobin levels.
Conclusions: The findings of this review suggest that patients with DM, particularly those with DR, exhibit altered melatonin production. Reduced systemic melatonin levels may correlate with increased risk and severity of DR. However, the majority of included studies had a case-control design, which hinders the ability to draw causal conclusions regarding the association between melatonin levels and DR. Moreover, confounding factors, including age, duration of DM, medication use, and lifestyle characteristics of participants, were not uniformly considered, and the limited sample sizes restrict the applicability of the results. Future investigations should emphasize longitudinal studies to clarify the temporal dynamics between melatonin levels and DR progression Additional investigations are required to clarify the function of melatonin in the pathogenesis of DR and its viability as a therapeutic target.
Treatment options for diabetic retinopathy in pregnancy
Mustafa Kayabasi, Omer Karti, Ali Osman Saatci
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 2 (2025), 31 July 2025 , Page 83-85
https://doi.org/10.51329/mehdioptometry226
Letter to the Editor
Spring 2025
Vol. 6 No. 1 (2025)
Myopia severity and corneal endothelium: morphological variations across low, moderate, and high myopia
Mohd Radzi Bin Hilmi, Nur Atikah Binti Yusof, James Stuart Wolffsohn
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 1 (2025), 1 May 2025 , Page 1-7
https://doi.org/10.51329/mehdioptometry215
Background: Myopia, a condition of growing concern in Asian populations, has been linked to ocular structural changes that may affect corneal endothelial morphology. Endothelial cell density (ECD), shape, and size changes have been observed in cases of high myopia. However, population-specific data, particularly in Malaysia, remain limited. In this study, we evaluated corneal endothelial morphology across different severities of myopia in young Malaysian adults.
Methods: For this cross-sectional study, we categorized individuals with myopia, aged 19–24 years, attending the International Islamic University Malaysia Optometry Clinic, into low, moderate, and high myopia groups, based on spherical equivalent. They underwent non-cycloplegic refraction, axial length, intraocular pressure, and slit-lamp assessments. Using a non-contact specular microscope, we measured corneal endothelial parameters, ECD (cells/mm²), coefficient of variation (CV) of the cell area, percentage of hexagonal cells (HEX, %), and central corneal thickness (CCT, micrometer) centrally, in triplicate, and averaged the values. All assessments were conducted by an experienced optometrist under controlled environmental conditions.
Results: We analyzed data from 374 eyes of 187 young adults (mean [standard deviation] age: 20.16 [0.75] years) across varying degrees of myopia. Axial length increased with myopia severity, while best-corrected visual acuity remained comparable among groups. Statistically significant differences in mean ECD, CCT, and HEX (all P < 0.05), but not in CV, were observed across the three myopia groups. Post-hoc analysis revealed that, compared to low myopia, the high myopia group had significantly lower ECD, HEX, and CCT (all P < 0.05), while the moderate myopia group showed significantly reduced ECD and HEX (both P < 0.05). ECD, CCT, and HEX did not differ significantly between the moderate and high myopia groups (all P > 0.05).
Conclusions: We demonstrated that higher myopia severity in young Malaysian adults was significantly associated with lower ECD, reduced HEX, and thinner CCT, whereas CV did not differ across myopia levels. These findings indicated that increasing myopia severity is associated with notable morphological changes in the corneal endothelium. Thus, progressive axial elongation in myopia may adversely impact corneal endothelial morphology and biomechanical stability. Given the cross-sectional nature and limited demographic scope of the study, further longitudinal and multi-ethnic studies are warranted to clarify the causal pathways and long-term implications of myopia-related endothelial changes.
Strip meniscometry in dry eye disease: correlations with standard diagnostic tests
Seyed-Hashem Daryabari , Mohammad Majid Ali-Akbari , Seyyed Morteza Hosseini Imeni
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 1 (2025), 1 May 2025 , Page 8-14
https://doi.org/10.51329/mehdioptometry216
Background: Dry eye disease (DED) is a multifactorial condition with a globally rising prevalence. Diagnosis relies on both symptoms and clinical tests, but these methods demonstrate variability. Strip meniscometry (SMTube) represents a rapid, non-invasive alternative method, but its diagnostic value remains uncertain. We evaluated the correlation of its findings with those of established DED evaluations.
Methods: In this cross-sectional study, we recruited 100 individuals with and without DED (n = 50 each) who visited a tertiary ophthalmology clinic. Diagnosis of DED was based on symptomatology and standard criteria, including a tear break-up time (TBUT) < 5 s or Schirmer test I result < 5 mm, along with an Ocular Surface Disease Index (OSDI) score > 12 and corneal fluorescein staining grade > 1. The exclusion criteria included ocular surgery, allergy, or contact lens use. All participants underwent comprehensive ophthalmic examination and standardized DED assessments (OSDI, tear meniscus height [TMH], SMTube, TBUT, corneal fluorescein staining, and Schirmer test I), conducted in a controlled setting by a single examiner during 9–11 AM to ensure consistency.
Results: The DED group was significantly older (P < 0.05). No significant sex difference was observed between groups (P > 0.05). The OSDI, TMH, SMTube, TBUT, corneal fluorescein staining, and Schirmer test I findings differed significantly (all P < 0.001), while SMTube application discomfort rates were similar between groups (P > 0.05). In the DED group, SMTube correlated moderately with TBUT (r = + 0.41, P < 0.05) and OSDI (r = + 0.43, P < 0.05), while the Schirmer test I correlated weakly with TBUT (r = + 0.34, P < 0.05) and moderately with TMH (r = + 0.52, P < 0.05). In the controls, no significant correlations were observed between tear metrics and SMTube or Schirmer test I findings (all P > 0.05), except for corneal fluorescein staining, which showed a weak negative correlation with SMTube (r = – 0.28, P < 0.05) and a moderate positive correlation with Schirmer test I findings (r = + 0.51, P < 0.05).
Conclusions: SMTube findings differed significantly between the DED and control groups and correlated moderately with those of established diagnostic assessments, particularly the TBUT and OSDI. Unlike Schirmer testing, SMTube results are closely associated with symptom severity, suggesting its utility in reflecting patient-reported discomfort. Given its simplicity, non-invasiveness, and correlation with key clinical indicators, SMTube may serve as a valuable adjunct in the multimodal assessment of DED. However, further studies are needed to establish its diagnostic accuracy and to confirm its clinical utility.
Visual and keratometric outcomes following corneal collagen cross-linking in keratoconus: an experience from Nepal
Nisha Kumari Barnwal , Sanjay Kumar Sah , Bibek Chaudhary , Pankaj Ray Adhikari , Rajiv Ranjan Karn
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 1 (2025), 1 May 2025 , Page 15-21
https://doi.org/10.51329/mehdioptometry217
Background: Keratoconus is a progressive corneal ectasia causing visual impairment, often initially managed using spectacles or rigid gas permeable contact lenses, which do not halt disease progression. Corneal collagen cross-linking (CXL) is the only treatment proven to stabilize the condition. Although its efficacy is well documented globally, data from Nepal are limited. This study evaluated visual and keratometric parameters before and after CXL in Nepali patients with varying severities of keratoconus.
Methods: This retrospective, hospital-based study analyzed visual acuity and keratometric outcomes in patients with keratoconus who underwent epithelium-off CXL at Biratnagar Eye Hospital, Biratnagar, Nepal, between January 2019 and March 2023. Secondary data were extracted from medical records. Only eyes with minimum corneal thickness greater than or equal to 400 µm were included. Patients were classified into Amsler–Krumeich stages I–IV. Pre- and 1-month post-CXL assessments included uncorrected and best-corrected distance visual acuity (UCDVA and BCDVA, respectively) both recorded in logarithm of the minimum angle of resolution, keratometry, slit-lamp biomicroscopy, corneal topography, and fundus evaluation.
Results: A total of 195 eyes from 106 patients with keratoconus were analyzed; 84.0% (n = 89) underwent bilateral CXL. The mean (standard deviation [SD]) age was 19.4 (4.9) years, with most (n = 43, 40.6%) aged 16–20 years. Male patients comprised 71.7% (n = 76) of the cohort. The mean (SD) follow-up duration after CXL was 7.5 (2.6) months. Following CXL, overall BCDVA improved, with statistically significant gains in stages I and IV (both P < 0.05). UCDVA significantly improved in stage II (P < 0.05). In stage I and II eyes, the average keratometry became flatter by –0.4 D and –0.2 D, respectively (both P < 0.05). The mean average keratometry remained comparable to baseline in stage III and IV eyes (both P > 0.05).
Conclusions: CXL is effective in stabilizing keratoconus in Nepali patients, particularly in early stages. Significant improvements in BCDVA, as well as keratometric flattening, were observed in stage I and IV and in stage I and II eyes, respectively. Although advanced-stage eyes (III and IV) showed keratometric stability without significant flattening, the results suggest that CXL can slow or halt disease progression even in later stages. These findings highlight the importance of early diagnosis and timely intervention. Further prospective, multicenter studies are warranted to optimize treatment protocols and expand the understanding of CXL outcomes in this patient population.
Impact of phacoemulsification with posterior chamber intraocular lens implantation on intraocular pressure and retinal structural parameters in pseudoexfoliation glaucoma and primary open-angle glaucoma
Ahmed A. Abdelghany, Moataz A. Sallam
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 1 (2025), 1 May 2025 , Page 22-28
https://doi.org/10.51329/mehdioptometry218
Background: Glaucoma, a leading cause of irreversible blindness, is increasingly prevalent, with pseudoexfoliation glaucoma (PEXG) presenting more severe optic nerve damage than primary open-angle glaucoma (POAG). Phacoemulsification reduces intraocular pressure (IOP), especially in PEXG; however, its effects on retinal structure remain unclear. This study compared the effects of IOP reduction post-phacoemulsification on the ganglion cell complex (GCC) in eyes with PEXG and cataract, POAG and cataract, and cataract alone over 12 months.
Methods: This prospective, quasi-experimental study included age- and axial length-matched patients with PEXG, POAG, or cataract alone undergoing standardized phacoemulsification with posterior chamber intraocular lens (PCIOL) implantation by a single surgeon using consistent techniques. Comprehensive ophthalmic assessments and spectral-domain optical coherence tomography imaging were performed preoperatively and at 3, 6, and 12 months postoperatively. Outcome measures included IOP, GCC thickness, retinal nerve fiber layer (RNFL) thickness, and vertical cup-to-disc ratio (CDR).
Results: Ninety eyes (30 per group) were analyzed. The mean (standard deviation [SD]) ages were 57.8 (5.8) years in the PEXG group, 58.0 (6.3) years in the POAG group, and 56.2 (4.6) years in the control group. There were 14 men (46.7%) and 16 women (53.3%) in both the PEXG and POAG groups, and 12 men (40.0%) and 18 women (60.0%) in the control group. The mean (SD) axial lengths were statistically similar at 23.9 (1.2) mm in the PEXG group, 23.9 (1.8) mm in the POAG group, and 23.8 (1.2) mm in the control group. Preoperatively, the PEXG group displayed higher IOP and thinner RNFL, whereas the POAG group featured thinner GCC and greater vertical CDR. Phacoemulsification significantly reduced IOP in both glaucoma groups (both P < 0.05), with a greater reduction in PEXG. However, no significant postoperative changes were observed in GCC thickness, RNFL thickness, or vertical CDR within any group (all P > 0.05). Despite this, intergroup differences in GCC, RNFL, and vertical CDR persisted at all follow-up points (all P < 0.05), although the PEXG and POAG groups did not significantly differ from each other (P > 0.05).
Conclusions: Phacoemulsification with PCIOL implantation significantly reduced IOP in eyes with PEXG and POAG, with a greater reduction observed in PEXG. However, this IOP reduction did not translate into significant changes in GCC thickness, RNFL thickness, or vertical CDR over 12 months. These findings suggest that although cataract surgery offers IOP-lowering benefits in early-stage glaucoma, it may not influence short-term structural progression, highlighting the need for ongoing postoperative monitoring and adjunctive management in glaucomatous eyes.
Optic nerve sheath diameter as a surrogate for intracranial pressure: a noninvasive follow-up strategy using ocular ultrasonography
Raghda Shawky El-Gendy , Ahmad Shehata Abd ElHamid , Ayman Ali El-Sayed Ali Galhom , Nihal Adel Hassan , Ehab Mahmoud Ghoneim
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 1 (2025), 1 May 2025 , Page 29-35
https://doi.org/10.51329/mehdioptometry219
Background: Idiopathic intracranial hypertension (IIH), characterized by increased intracranial pressure (ICP) without a clear cause, typically affects obese women of reproductive age. Although lumbar puncture (LP) is diagnostic, its invasiveness limits its repeated use. Consequently, a non-invasive alternative is essential. Therefore, we assessed whether optic nerve sheath diameter (ONSD) measurement via orbital ultrasonography could serve as an alternative method for monitoring changes in ICP in patients with IIH.
Methods: In this prospective observational study, patients with IIH, diagnosed using the modified Dandy criteria, underwent ONSD assessment using B-scan ultrasonography. Bilateral measurements were performed 3 mm posterior to the optic disc with the probe and sterile gel placed on the closed upper eyelid. ONSD was recorded before LP and one month after initiation of medical treatment. Comprehensive ophthalmologic examinations were also conducted. Patients with ocular pathology, neuroimaging abnormalities, or contraindications to LP were excluded.
Results: Twenty-four eyes from 12 female patients with IIH were evaluated. The mean (standard deviation [SD]) age was 27.3 (6.9) years, and the mean ICP was 34.8 (10.3) cm H2O. Although the ONSD decreased one month after LP, changes in mean ONSD of the right eye, left eye, and their average were not statistically significant (all P > 0.05). No significant correlations were observed between baseline ICP and ONSD values (all P > 0.05).
Conclusion: Although ONSD measurement via ultrasonography provides a noninvasive method for assessing ICP in IIH, our findings revealed no significant change one month after treatment initiation. ONSD may gradually decrease following LP; however, a return to baseline values appears to require a prolonged period, even after ICP normalization. This should be considered during patient follow-up. Our findings underscore the limitations of using ONSD as a standalone marker for monitoring therapeutic response. Further research is warranted to explore the factors influencing ONSD dynamics and to establish standardized, patient-centered measurement protocols.
Curcumin in ocular diseases: therapeutic potential, mechanisms of action, and innovative delivery systems
Pegah Rashidian
Medical hypothesis, discovery & innovation in optometry, Vol. 6 No. 1 (2025), 1 May 2025 , Page 36-42
https://doi.org/10.51329/mehdioptometry220
Background: Curcumin, a natural polyphenol derived from Curcuma longa L., has gained considerable attention in ophthalmology because of its potent anti-inflammatory, antioxidant, and immunomodulatory properties. This review evaluates the therapeutic potential of curcumin in ocular diseases and explores innovative strategies to enhance its bioavailability.
Methods: A comprehensive search was conducted in four major electronic databases—PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar—using keywords related to curcumin, ophthalmology, and drug delivery systems. Studies published in English up to March 10, 2025, were included. Relevant articles were selected based on their focus on the therapeutic effects of curcumin and the application of advanced delivery methods.
Results: Curcumin shows promising therapeutic potential in various ocular conditions due to its anti-inflammatory, antioxidant, and anti-angiogenic properties. Studies highlight its beneficial effects in corneal neovascularization, promoting corneal wound healing, and dry eye disease. It also demonstrates efficacy against allergic and bacterial conjunctivitis, pterygium recurrence, anterior uveitis, and cataracts. Moreover, curcumin may be beneficial in glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy, offering a multi-targeted approach to preserving vision and ocular health. However, its poor bioavailability remains a major limitation. Strategies to overcome this challenge include the development of structural analogs, bioavailability enhancers, and advanced drug delivery systems such as nanoparticles, liposomal systems, micelles, hydrogel-based systems, and nanoemulsions, all of which may enhance the stability, bioavailability, and controlled release of curcumin.
Conclusions: Curcumin has garnered attention in ophthalmology because of its multifaceted therapeutic properties, including anti-inflammatory, antioxidant, apoptosis regulating, antibacterial, and immunomodulatory actions. These properties have demonstrated promising results, highlighting the potential of curcumin in treating various ophthalmic conditions. Despite the promising potential of curcumin in ophthalmic therapies, addressing its poor bioavailability by using innovative drug delivery systems is crucial for maximizing its clinical efficacy. To address these challenges, substantial research has focused on enhancing the bioavailability of curcumin through the development of structural analogs, bioavailability enhancers, and advanced drug delivery systems. Innovative formulations, including nanoparticles, liposomal systems, micellar solutions, hydrogel-based systems, nanoemulsions, microspheres, and transferosomes, are promising approaches to improve the stability, bioavailability, and controlled release of curcumin, offering a hopeful avenue for its future application in ocular therapies.
Winter 2024
Vol. 5 No. 4 (2024)
The impact of coronavirus disease on ocular trauma: a review of 5065 cases from Kuwait
Ebrahem Alansari, Nora Aldhefeery, Sherein Hagras, Nancy M Lotfy
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 4 (2024), 2 March 2025 , Page 145-151
https://doi.org/10.51329/mehdioptometry209
Background: Early reports during the lockdown associated with the coronavirus disease 2019 (COVID-19) pandemic indicated a shift in the trends of ocular injuries. This study examined the demographics and clinical characteristics of patients who presented with ocular trauma during the lockdown period in 2020, and compared them to those seen during the same months in the next year, after the lockdown had been lifted, at Farwaniya Hospital in Kuwait.
Methods: This retrospective hospital-based chart review was a comparative observational study that examined individuals who presented to the Ophthalmology Department’s emergency room during two distinct periods: from March 22, 2020, the day quarantine measures were announced, until August 30, 2020, when the quarantine ended, and the same time frame in the following year. Demographic characteristics, diagnoses, mechanisms of ocular trauma, and the locations where the eye injuries had occurred were recorded. Local injuries were classified as either mechanical or non-mechanical. Mechanical injuries were further subdivided by their cause. Non-mechanical injuries encompassed those caused by burns or corrosive substances.
Results: The incidence of ocular trauma increased from 18.9% (1470 out of 7763 cases) during the lockdown to 21.5% (3595 out of 16 748 cases) in the post-lockdown period. The mean age of the study population was slightly lower during the lockdown compared to the post-lockdown period, although this difference did not reach statistical significance (P > 0.05). Ocular trauma among children < 18 years was significantly higher during the lockdown period, accounting for 39.1% (575 of 1470 cases), compared to 36.0% (1293 of 3595 cases) in the post-lockdown period (P < 0.05). During both periods, injuries predominantly occurred at home, but the percentage of injuries decreased significantly during the post-lockdown period (P < 0.05). Workers were the most affected group, representing nearly 50% of cases during both periods. During the lockdown, 29.9% (439 cases) of ocular trauma cases involved work-related injuries, but this percentage increased significantly to 33.7% (1213 cases) post-lockdown (P < 0.05). Mechanical injuries constituted the majority of cases in both periods, accounting for almost 95% of the incidents, with a significant difference between the two periods (P < 0.05). Non-mechanical eye injuries did not differ between the two periods (P > 0.05). Most ocular trauma cases involved the anterior segment of the eye, with superficial corneal and conjunctival injuries being predominant, accounting for > 50% of cases during both periods.
Conclusions: The COVID-19 pandemic significantly impacted the trends in cases visiting ophthalmic emergency departments. After the lockdown, the incidence of ocular trauma increased. Ocular trauma among children was significantly higher during the lockdown period. The frequency of home-related ocular injuries was greater during the lockdown than in the post-lockdown phase. Work-related injuries showed a marked increase after the lockdown. Long-term, retrospective multicenter epidemiological studies in Kuwait could shed light on changes in the use of eye emergency department services during pre- and post-pandemic periods.
Depression, anxiety, and stress indicators for patients who are blind or visually impaired
Rokiah Omar, Putera Mohd Farhan Najwan Mohd Rizal, Mahadir Ahmad, Chiranjib Majumder, Victor Feizal Knight
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 4 (2024), 2 March 2025 , Page 152-159
https://doi.org/10.51329/mehdioptometry210
Background: Severe visual impairment is reportedly detrimental to mental health. Blind individuals are expected to have poorer mental health status compared to those with low vision. However, most mental health studies have focused on people with low vision, leaving a substantial gap in our understanding of the mental health status of the blind. Therefore, this study compared the mental health status of individuals with low vision to that of blind individuals.
Methods: This cross-sectional, questionnaire-based investigation involved individuals with low vision or blindness who were registered with the Social Welfare Department, Federal Territory of Kuala Lumpur, Malaysia. Participants were recruited using a simple random sampling method. The medical records of each participant were screened. Participants were individually interviewed, and their socio-demographic details, education level, working status, marital status, type and duration of impairment, and rehabilitation status were collected. Additionally, the Depression, Anxiety, and Stress Scale (DASS-21) was administered to each individual.
Results: Of the 30 participants, 20 (66.7%) had low vision and 10 (33.3%) had blindness, 16 (53.3%) were men, and most participants were single (n = 20, 66.7%). Congenital and acquired causes of visual impairment each accounted for 50% of cases. Most participants (n = 26, 86.7%) had not received psychosocial rehabilitation. The mean DASS-21 scores for the depression, anxiety, and stress subscales were significantly higher in patients with low vision than in those with blindness (all P < 0.05). Considering the clinical cut-off increments to determine emotional states for the DASS-21 subscales, individuals with low vision were in the mild, moderate, and mild categories for the depression, anxiety, and stress subscales, respectively. Individuals with blindness were categorized as normal in all subscales. The mean DASS-21 scores for the depression, anxiety, and stress subscales among individuals with congenital and acquired causes of visual impairment were comparable (all P > 0.05). Individuals with congenital visual impairment were in the normal, moderate, and normal categories for the depression, anxiety, and stress subscales, respectively. Those with acquired visual impairment were categorized as mild, moderate, and normal for the depression, anxiety, and stress subscales, respectively.
Conclusions: Individuals with low vision experienced mild to moderate levels of mental health issues, which may consist of depression, anxiety, stress, or a combination of these. The blind individuals in this study demonstrated no similar mental health issues. The small number of participants in certain racial and age groups prevents us from concluding how these factors might influence mental health. Further research with a larger sample size should consider the severity of visual impairment, age groups, and ethnicity, as these factors may impact the outcomes.
Visual outcomes of monocular idiopathic epiretinal membrane removal: a prospective follow-up study
Masood Bagheri, Fatemeh Hoseini, Armin Asiaei
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 4 (2024), 2 March 2025 , Page 160-168
https://doi.org/10.51329/mehdioptometry211
Background: Surgical intervention for an idiopathic epiretinal membrane (iERM) could alleviate metamorphopsia or improve vision. We evaluated changes in vision in patients undergoing treatment for monocular iERMs during a 6-month period. We investigated the rate of posterior vitreous detachment (PVD) using optical coherence tomography (OCT) imaging in eyes with iERM and in normal fellow eyes. We also examined the intraoperative rate of PVD in iERM eyes following the administration of triamcinolone acetonide (TA).
Methods: This prospective interventional case series recruited all eligible individuals with treatment-naive monocular iERM who were scheduled for pars plana vitrectomy (PPV) due to reduced best-corrected distance visual acuity (BCDVA) or metamorphopsia. OCT at baseline was used to determine the presence and stage of PVD in the eyes with iERM and the normal fellow eyes. Intraoperative TA-based PVD staging was performed for affected eyes.
Results: Participants comprised 32 cases, with 32 eyes with iERM and 32 normal fellow eyes. The mean (standard deviation [SD]) age was 60.9 (9.7) years, and the majority were men (n = 18, 56.2%). The baseline mean (SD) of BCDVA in affected eyes was 0.50 (0.21) logarithm of the minimum angle of resolution (logMAR), which improved to 0.34 (0.20) logMAR at the 1-month visit, representing a significant mean difference of 0.15 (0.20) logMAR (P < 0.001). At the 6-months visit, the mean (SD) BCDVA had further improved to 0.26 (0.19) logMAR, representing a significant mean difference of 0.23 (0.26) logMAR (P < 0.001) from the baseline value. The mean (SD) visual improvement between the 1- and 6-months follow-ups was 0.07 (0.14) logMAR, which was statistically significantly (P < 0.05). The mean changes in BCDVA were more pronounced in patients aged < 60 years than in those aged 60 years or older. The proportion of eyes at each stage of PVD detected by preoperative OCT in eyes with iERM differed from that detected by intraoperative TA staining. By both methods, the stages advanced significantly with increasing age (both P < 0.001). Similarly, the proportion of eyes at each stage of PVD detected by preoperative OCT in the normal fellow eyes was also higher and advanced significantly with increasing age (P < 0.001).
Conclusions: Continuous visual improvement is anticipated up to 6 months after surgery in eyes with iERM, and this improvement is likely to be more significant in younger individuals. The incidences of each PVD stage varies depending on the use of preoperative OCT or intraoperative TA in these cases. A higher rate of PVD observed in fellow eyes may suggest that PVD progresses through its stages simultaneously and without complications in normal eyes. Further studies are needed to validate our preliminary results and confirm these conclusions.
Update on coronavirus disease and retinal artery occlusion
Marianne L Shahsuvaryan
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 4 (2024), 2 March 2025 , Page 169-177
https://doi.org/10.51329/mehdioptometry212
Background: The novel coronavirus disease 2019 (COVID-19) is significant not only for its life-threatening impact, but also for its association with serious eye disorders, including retinal artery occlusion. This language-inclusive narrative review analyzed the available clinical literature on retinal artery occlusion linked to COVID-19, highlighting it as a serious vision-threatening complication of this disease during the recent pandemic.
Methods: A targeted literature search was conducted in the PubMed / MEDLINE and Google Scholar databases from January 1, 2020, to January 1, 2025, to gather the most recent evidence. Studies were identified through various combinations of the following search terms: “eye diseases in COVID-19,” “ocular findings,” “ocular manifestations in COVID-19,” “posterior segment alterations in COVID-19,” and “retinal artery occlusion in COVID-19.” Articles with relevant clinical significance were selected for review. The reference lists of these papers also manually checked for other relevant papers. We included case reports, case series, and both prospective and retrospective studies that reported cases of central retinal artery occlusion (CRAO) or branch retinal artery occlusion (BRAO) in patients of any age, sex, and race with confirmed COVID-19.
Results: We found 27 records, of which 21 reported cases of CRAO in patients with COVID-19. The mean (standard deviation) age of these patients was 54.1 (13.4) years (range: 30–77 years). Off the 21 patients, 18 (86%) were men and three (14%) were women. In three cases, bilateral involvement was noted; in one such instance, CRAO was diagnosed sequentially: in the left eye while the patient had COVID-19, and in the right eye 1.5 months later. Among the cases of unilateral CRAO, the left eye was the most frequently affected. Additionally, four cases of BRAO were reported in patients with COVID-19, with most of these patients being women. Most of these cases were diagnosed in the left eye within 1 month of a COVID-19 diagnosis. Notably, in the majority of cases involving CRAO or BRAO, vascular thromboembolic events were not reported. Additionally, two case series reported a total of 17 patients with COVID-19 who were diagnosed with CRAO.
Conclusions: Although strong evidence of a causal relationship is lacking, healthcare specialists should be aware that CRAO or BRAO may be ocular complications of COVID-19. This is particularly important with the emergence of new subvariants of SARS-CoV-2 and in asymptomatic patients, and considering the availability of rapid viral antigen tests will make it easier to check if the patient with CRAO or BRAO actually have asymptomatic COVID-19.
Ocular side effects of systemic medications
Kimia Kazemzadeh
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 4 (2024), 2 March 2025 , Page 178-186
https://doi.org/10.51329/mehdioptometry213
Background: Systemic medications, which are crucial for managing a wide range of diseases from hypertension and diabetes to infections and cancers, can induce substantial ocular side effects. These effects impact visual function and quality of life, necessitating awareness and monitoring by healthcare professionals. The current review summarizes the range and mechanisms of these ocular toxicities.
Methods: This narrative review was derived from a targeted literature search using major electronic databases including PubMed/MEDLINE, Embase, Scopus, and Google Scholar. Keywords related to ocular side effects of systemic medications were utilized to identify relevant studies published from January 1, 2000, to December 30, 2024. The included articles pertained to ocular manifestations of systemic drug use, their mechanisms of toxicity, and associated management strategies.
Results: This study identified notable ocular side effects related to various systemic medications. Amiodarone was consistently linked to corneal deposits and colored halos, prompting recommendations for regular eye examinations. Isotretinoin was frequently associated with dry mucous membranes and blepharoconjunctivitis. Chloroquine and hydroxychloroquine were found to cause corneal changes and irreversible retinal damage with prolonged use. Studies of allopurinol presented conflicting evidence regarding its relationship with cataract risk. Corticosteroid use was associated with cataract formation and potential elevation of intraocular pressure. Ethambutol has been identified as a potential cause of optic neuritis. Topiramate was linked to acute angle-closure glaucoma, particularly early in treatment. Anticholinergic drugs can impact various parts of the eye. They cause ciliary muscle relaxation, leading to temporary blurred vision. This loss of accommodation, also known as “iatrogenic presbyopia,” results from paralysis of the ciliary muscle. Phosphodiesterase type 5 inhibitors, such as sildenafil, may cause pupil dilation, redness, dryness, blurred vision, and temporary cyanopsia. Additionally, patients taking vigabatrin may experience progressive constriction of the visual fields, necessitating regular visual field assessments. Epidemiological studies indicate that approximately 15% of patients taking systemic medications experience dry eye syndrome. These findings underscore the diverse range and impact of drug-induced ocular toxicities. However, vigilant monitoring and prompt management can help mitigate vision-threatening complications and preserve patients’ visual health. Addressing these ocular side effects requires strong interdisciplinary communication among ophthalmologists, optometrists, primary care physicians, and other specialists.
Conclusions: The wide range of ocular manifestations of systemic medication use emphasizes the importance of monitoring patients for these side effects. Collaborative management by eye care professionals and prescribing physicians is vital to mitigate risks. Further research must focus on the mechanisms of drug-induced ocular toxicity and developing effective preventive measures.
Ocular manifestations of opiate and alcohol
Nima Rastegar Rad
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 4 (2024), 2 March 2025 , Page 187-189
https://doi.org/10.51329/mehdioptometry214
Letter to the Editor
Fall 2024
Vol. 5 No. 3 (2024)
Validation of the Arabic version of the Contact Lens Dry-Eye Questionnaire-8 in Palestine
Mohammed Aljarousha, Waleed M Alghamdi, Mohd Zaki Awg Isa , Noor Ezailina Badarudin, Fairuz Mohd Nordin, Mohd Ferdaus Bin Sari, Ebrahim Nangarath Kottakal Cheriya, Sara Attaallah, Mohammed Abdelfatah Alhoot
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 3 (2024), 25 January 2025 , Page 93-102
https://doi.org/10.51329/mehdioptometry203
Background: The Tear Film and Ocular Surface Society International Workshop on Contact Lens Discomfort has stated that the Contact Lens Dry Eyes Questionnaire (CLDEQ-8) is the only validated clinical tool for assessing dry eye related to the use of soft contact lenses. Although translations of this questionnaire into various languages have been validated, the translation into Arabic has not been validated. We aimed to translate and validate the Arabic version of the CLDEQ-8 questionnaire in a clinical context among a sample of Arabic-speaking soft contact lens wearers residing in Palestine.
Methods: The CLDEQ-8 was translated into Arabic via a five-stage process: forward translation, translation revision, backward translation, refinement, and prefinal testing. The content validity of the questionnaire was assessed by a panel of 19 experts by using the Content Validity Ratio (CVR) and the Content Validity Index (CVI). After reviewing the pre-test results, the Arabic-CLDEQ-8 was finalized. For clinical validation, a web-based version of the Arabic-CLDEQ-8 was distributed to eligible soft contact lens wearers in Gaza, Palestine. Internal consistency was evaluated using Cronbach’s alpha and the Corrected Homogeneity Index.
Results: Thirty-four soft contact lens wearers, with a mean (standard deviation [SD]) age of 23.9 (5.7) years and with a mean (SD) contact lens-wear time was 10.5 (7.5) hours, including 30 (88.2%) women, completed the questionnaires. The mean (SD) score on the Arabic-CLDEQ-8 was 17.00 (6.69) (range: 2–30). Cronbach’s alpha, indicating internal consistency, was 0.900, and the corrected homogeneity index exceeded 0.50 for all assessed domains, except for domain 4 (D4). The CVI and CVR were 0.73 and 0.87, respectively. Domains D1a, D1b, D2a, D3a, D3b, and D4 were found to be clear and simple, while domain D2b demonstrated an average level of content validity.
Conclusions: The trans-cultural adaptation of the CLDEQ-8 questionnaire led to the development of a reliable and valid tool for assessing the contact lens comfort among Arabic-speaking soft contact lens wearers. This Arabic-CLDEQ-8 was culturally adapted for Arabic-speaking contact lens wearers living in Palestine; thus, future studies should aim to confirm its validity in other Arabic-speaking regions.
Accommodative functions in opium users and non-users
Tahereh Sadat Khoshnazar, Mehdi Sharifzadeh Kermani, Monireh Mahjoob, Masoud Sadeghi
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 3 (2024), 25 January 2025 , Page 103-111
https://doi.org/10.51329/mehdioptometry204
Background: Emerging evidence highlights a concerning prevalence of accommodative and convergence anomalies in individuals with opioid use disorder. However, there remains a significant scarcity of data comparing accommodative functions of opium users and non-users. Hence, we investigated potential changes in accommodative functions of opium users compared to that of non-users. Furthermore, we evaluated changes in these parameters after administering 5% phenylephrine eye drops, both within and between the two groups.
Methods: This cross-sectional case-control study recruited opium users and non-users. The binocular amplitude of accommodation (AA), monocular estimate method (MEM), negative and positive relative accommodation (NRA and PRA, respectively), and monocular and binocular accommodative facility (AF) were assessed and documented. All measurements were repeated 30 min after instillation of one drop of 5% phenylephrine hydrochloride eye drops.
Results: We recruited 103 opium users and 107 non-users, with comparable mean ages (P > 0.05) but significantly different sex ratios (P < 0.05), with men outnumbering women among the opium users. All accommodative functions measured before and after the instillation of 5% phenylephrine, along with the differences in their values between the two time points, were comparable between the two groups (all P > 0.05), with the exception of the right-eye AF, which was significantly higher in non-users than in opium users after instillation (P < 0.05). Within the opium user group, all accommodative functions exhibited significant differences between pre- and post-instillation measurements (all P < 0.05), except for NRA, which did not change (P > 0.05). In contrast, the non-user group showed no significant differences between pre- and post-instillation measurements for all accommodative functions (all P > 0.05), except in the AA and the right-eye MEM (both P < 0.05).
Conclusions: We observed small but significant changes in most baseline accommodative functions after the application of 5% phenylephrine eye drops in opium users. In contrast, most parameters remained unchanged in healthy non-users. When comparing the results between the two groups pre- and post-application of phenylephrine, we found similar accommodative functions overall. However, non-users had a significantly higher value for the right-eye AF following the instillation. To better understand potential binocular anomalies in opium users, further longitudinal studies that are matched for age and sex should be conducted, focusing on additional aspects of binocular vision and ocular motility.
Refractive and visual outcomes of traumatic cataract surgery: a ten-year perspective
Seyed Hashem Daryabari, Khosrow Jadidi, Hamidreza Torabi, Mahmood Hassani, Mohammad Yaser Kiarudi, Mohammadreza Saeedifar
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 3 (2024), 25 January 2025 , Page 112-118
https://doi.org/10.51329/mehdioptometry205
Background: Traumatic cataract is a major consequence of penetrating and blunt ocular injuries, often requiring surgical intervention. We evaluated the visual and refractive outcomes of traumatic cataract surgery and intraocular lens (IOL) implantation in adults who sustained open- or closed-globe injuries.
Methods: Patients who underwent cataract surgery and IOL implantation due to closed or open eye injuries were included in this descriptive-analytical, retrospective, case-series study. Eligible patients were scheduled for re-evaluation and a complete ocular re-examination, and individuals who returned and had a follow-up of at least 6 months were ultimately recruited. Because the accuracy of IOL power calculation was a primary outcome, patients who were left aphakic were excluded. Medical records were also reviewed to document baseline data, surgical details, and complications.
Results: We included 72 eyes of 72 patients with a mean (standard deviation [SD]) age of 39.5 (13.6) years and a male-to-female ratio of approximately 6:1. Forty-one (56.9%) eyes sustained open-globe injuries and 31 (43.1%) closed-globe injuries. The mean (SD) initial best-corrected distance visual acuity (BCDVA) was 1.1 (0.6) logarithm of the minimum angle of resolution (logMAR) and improved significantly to 0.3 (0.3) logMAR at the final visit (P < 0.001). A final BCDVA better than 20/40 was detected in 43 (59.7%), 23 (74.2%), and 20 (48.8%) eyes in the entire series, eyes sustaining closed-globe injuries, and those with open-globe injuries, respectively. The absolute prediction error was 1.0 diopter or less in 42 (58.3%) eyes in the entire series. A mean absolute prediction error of 1.0 D or less was more frequent in closed-globe than in open-globe injuries (n = 22 [71.0%] vs. n = 20 [48.8%], respectively). The mean absolute prediction error differed significantly between groups (P < 0.05). Eyes that sustained open-globe injury were less likely to obtain a BCDVA better than 20/40 (odds ratio, 0.33; 95% confidence interval, 0.12 – 0.91; P < 0.05).
Conclusions: Visual acuity significantly improved after traumatic cataract extraction with IOL implantation. Most cases achieved satisfactory visual and refractive outcomes. Eyes with open-globe injuries might have less favorable visual prognosis. These initial findings must be confirmed through large-scale, multi-center longitudinal studies.
Relationship between central corneal thickness and optic nerve head parameters in primary open-angle glaucoma
Naseh Hakimzadeh, Sakineh Kadivar, Mohammad Reza Panjtan Panah
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 3 (2024), 25 January 2025 , Page 119-126
https://doi.org/10.51329/mehdioptometry206
Background: Primary open-angle glaucoma (POAG) is an ocular entity that causes optic neuropathy. Thin central corneal thickness (CCT) in patients with POAG correlates with changes in various optic nerve head structural parameters. Additionally, racial differences exist in CCT and optic disc parameters. Herein, we assessed the potential relationship between CCT and optic nerve head parameters in treatment-naive patients of Persian ethnicity who were diagnosed with POAG of varying severity levels.
Methods: This hospital-based analytical cross-sectional study recruited patients of Persian ethnicity diagnosed with treatment-naive POAG. Participants underwent detailed optometric and ophthalmic examinations. Visual field testing was performed using a Humphrey perimeter. Spectral-domain optical coherence tomography (OCT) was performed using a Cirrus OCT device to record optic nerve head parameters: disc area, rim area, vertical cup-to-disc ratio, average cup-to-disc ratio, cup volume, and average retinal nerve fiber layer thickness (RNFLT). The CCT was measured using an ultrasonic pachymeter.
Results: We recruited 168 eyes of 84 patients with POAG with a mean (standard deviation) age of 60.30 (12.50) years, comprising 33 (39.29%) men and 51 (60.71%) women. While weak but statistically significant inverse correlations of CCT with the vertical cup-to-disc ratio (r = – 0.19; P < 0.05), average cup-to-disc ratio (r = – 0.17; P < 0.05), and cup volume (r = – 0.17; P < 0.05) were found, other optic nerve parameters showed no significant correlations with CCT (all P > 0.05). Stepwise multiple linear regression analysis indicated that, for each unit increase in the vertical cup-to-disc ratio, the CCT decreased by 54.98 µm (P < 0.05).
Conclusions: The CCT in eyes with treatment-naive POAG of varying severity levels in a Persian ethnic group was weakly but statistically significantly inversely correlated with the vertical cup-to-disc ratio, average cup-to-disc ratio, and cup volume. For every unit increase in the vertical cup-to-disc ratio, the CCT decreased by 54.98 µm. Our findings indicate that in patients with POAG, CCT correlates with some changes in structural optic nerve head parameters, including the cup volume and vertical/average cup-to-disc ratios. Further longitudinal studies including individuals from various racial backgrounds and POAG severity levels are needed to verify the relationship between CCT and optic nerve parameters at different time points of disease progression.
Grading scales for vitreous haze
Omer Karti, Ali Osman Saatci
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 3 (2024), 25 January 2025 , Page 127-135
https://doi.org/10.51329/mehdioptometry207
Background: Grading scales for vitreous haze are crucial for the diagnosis, monitoring, and management of uveitis. The presence of inflammatory cells within the vitreous cavity is widely recognized as a key indicator of disease activity and severity, offering valuable insights into the underlying inflammatory processes. This mini-review aims to explore the evolution of vitreous haze grading scales systematically, emphasizing conventional grading methods, advances in imaging technologies, and the integration of artificial intelligence (AI) into the grading process.
Methods: The PubMed/MEDLINE database was comprehensively searched for studies published between 1959 and 2024, using keywords such as “AI-based grading systems,” “artificial intelligence,” “automated grading,” “grading scales for vitreous cells,” “inflammation,” “uveitis,” and “vitreous haze.” Relevant studies were identified, and additional articles were selected by reviewing the reference lists of the included publications. The selection of articles for inclusion in the mini-review was limited to those written in English.
Results: In the current literature, two grading methods are used: the National Institutes of Health (NIH) scale and the Miami scale. Despite their widespread utilization, both scales entail subjective assessments of vitreous haze, which renders them susceptible to observer bias and interobserver variability. The NIH scale uses six levels, while the Miami scale employs nine levels, both of which require subjective assessments of vitreous haze. Recent advances in objective imaging technologies, namely ultrawide-field fundus photography and advanced optical coherence tomography-based analysis, have given rise to increasingly consistent and standardized grading systems, which may enhance the reliability of these assessments. Innovative techniques have been developed to enhance accuracy and sensitivity, thereby facilitating the early detection and precise monitoring of vitreous inflammation. Despite these advances, challenges remain, including the difficulty of distinguishing subtle variations in vitreous haze and the variability of inflammatory presentations. The incorporation of AI-driven tools and state-of-the-art imaging technologies into the vitreous cell grading signifies a substantial advance in the evaluation and management of uveitis.
Conclusions: The development of more objective, reproducible, and quantitative grading scales is imperative for optimizing uveitis evaluation and grading vitreous haze in clinical settings and clinical trials. These innovations will also provide robust endpoints for clinical studies, ultimately improving patient care. Moreover, objective grading criteria will enhance diagnostic precision, facilitate better management of ocular inflammatory diseases, and promote further advances in uveitis research and treatment.
Choroidal melanoma treatment: a shift towards vision preservation
Kimia Kazemzadeh
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 3 (2024), 25 January 2025 , Page 136-144
https://doi.org/10.51329/mehdioptometry208
Background: Choroidal melanoma is the most common primary intraocular malignancy in adults, and is known for its aggressive nature and potential for metastasis. Historically, enucleation was the primary treatment, which resulted in significant morbidity and psychological distress. Recent advances have led to a paradigm shift towards vision-preserving therapies. This review aimed to explore advances in choroidal melanoma treatment and their impact on patient care and quality of life.
Methods: For this narrative review, we conducted a literature search of major databases, including PubMed/MEDLINE, Embase, and Scopus, from January 1, 1998, to December 30, 2024. The search strategy employed the following keywords: “choroidal melanoma,” “vision preservation,” “plaque brachytherapy,” “proton beam therapy,” “stereotactic radiosurgery,” “enucleation,” “ocular oncology,” “retinal health,” “visual acuity,” “quality of life,” “computational intelligence,” and “AI (artificial intelligence).” We included English-language studies of any design focusing on choroidal melanoma treatment, particularly treatment involving vision-preserving strategies.
Results: Advances in vision-preserving therapies, such as plaque brachytherapy, proton-beam irradiation, and stereotactic radiosurgery, have revolutionized the management of choroidal melanoma. These modalities offer improved patient outcomes by reducing the need for enucleation and preserving visual acuity. Plaque brachytherapy achieves high tumor-control rates with minimal side effects, while proton-beam irradiation provides precise tumor targeting, which is particularly beneficial for large tumors. Stereotactic radiosurgery is effective for smaller tumors, but may result in decreased visual acuity over time. Emerging therapies, such as Bel-Sar (AU-011), show promise in controlling tumor growth while preserving vision. The ability of Bel-Sar to control tumors while preserving vision could provide patients with a more favorable prognosis and improved quality of life. Immunotherapy holds significant promise, particularly with the potential for use of immune checkpoint inhibitors and vaccine therapies. Additionally, artificial intelligence (AI) is becoming increasingly important in the management of choroidal melanoma.
Conclusions: The shift from enucleation to vision-preserving therapies has significantly improved outcomes and quality of life for patients with choroidal melanoma. Future research should focus on optimizing current therapies for better visual acuity preservation and on exploring new targeted therapies to enhance tumor control while minimizing side effects. Moreover, studies on AI applications for managing this sight- and life-threatening eye condition could significantly transform treatment outcomes.
Summer 2024
Vol. 5 No. 2 (2024)
Ocular biometry parameters in mobile cataract surgery camp: a large-scale report from Nigeria
Ernest N Ogbedo, Ugochukwu A Eze, Helen A Alen, Adedeji O Akinyemi, Abiola A Salimonu
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 2 (2024), 1 September 2024 , Page 51-56
https://doi.org/10.51329/mehdioptometry197
Background: Humanitarian missions and mobile camp surgeries have pivotal roles in the uptake of cataract surgery in areas with limited resources. Ocular biometry is an important preoperative evaluation tool for cataract surgery candidates. Herein, we report the distributions of ocular biometric values among cataract surgery candidates in camp settings in southern Nigeria.
Methods: In this cross-sectional study, we retrieved data from consecutive patients scheduled for cataract surgery. All patients underwent a full ophthalmic examination using a slit-lamp biomicroscope. Age, sex, and preoperative biometric values, including anterior chamber depth (ACD), lens thickness (LT), vitreous chamber depth (VCD), and axial length (AL), together with intraocular lens (IOL) power, were documented. Biometric values were obtained using A-mode ultrasonography.
Results: Records of 567 patients with a mean (standard deviation) age of 66.0 (13.4) years revealed a male-to-female sex ratio of 1:1.24. Most participants were in the 66–70-year age group. Mean IOL power was significantly different between males and females (P < 0.001). However, the biometric values were comparable between sexes (all P > 0.05). There were significant differences in the mean IOL power (P < 0.001) and ACD (P < 0.05) between the age groups, indicating a decrease in ACD with age. However, the other biometric parameters were comparable between the age groups (all P > 0.05). ACD had a significant weak negative correlation with LT (r = – 0.16; P < 0.001) and IOL power (r = – 0.22; P < 0.001) and a positive correlation with AL (r = + 0.24; P < 0.001). LT had a significant weak negative correlation with VCD (r = – 0.16; P < 0.001) and a positive correlation with AL (r = + 0.09; P < 0.05). VCD had significant moderate positive and negative correlations with AL (r = + 0.39; P < 0.001) and IOL power (r = – 0.34; P < 0.001), respectively. AL had a significant strong negative correlation with IOL power (r = – 0.78; P < 0.001).
Conclusions: This study presents the mean distributions of ocular biometric parameters among cataract surgery candidates in camp settings in southern Nigeria. Age and sex were important determinants of IOL power and should be considered when planning eye camp supplies. AL had a strong inverse correlation with IOL power. Further multicenter national studies are required to verify these preliminary findings.
Astigmatism among schoolchildren in Mumbai, India: a large, population-based study
Mumtaz Qazi, Priyanka Singh
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 2 (2024), 1 September 2024 , Page 57-62
https://doi.org/10.51329/mehdioptometry198
Background: Astigmatism is a common refractive error. If left untreated, it may result in blurred or distorted vision. We determined the prevalence of astigmatism in schoolchildren aged 6–16 years in Mumbai, India.
Methods: A cross-sectional study was conducted using a stratified cluster random sampling method. We included primary and secondary schoolchildren aged 6–16 years. All children underwent a comprehensive eye examination. Astigmatism was characterized as having a diopter cylinder (DC) power of 0.50 or more in at least one eye, and for prevalence estimation, we reported the number of children with astigmatism. Astigmatism severity was defined as mild (less than or equal to – 1.50 DC), moderate (- 1.50 DC to – 2.50 DC), and severe (> – 2.50 DC). Based on the axis orientation, astigmatism was categorized as with-the-rule, against-the-rule, and oblique.
Results: A total of 3151 schoolchildren with a mean (standard deviation) age of 12.1 (2.9) years were screened; boys and girls accounted for 49.22% and 50.78%, respectively. Age groups of 6–9, 10–13, and 14–16 years accounted for 51.35%, 28.53%, and 20.12%, respectively. The overall prevalence of astigmatism was 11.46%, with no significant difference between sexes (P > 0.05). The prevalences of astigmatism in the groups aged 6–9-, 10–13-, and 14–16 years were 5.24%, 3.49%, and 2.73%, respectively. Prevalence differed significantly among age groups (P < 0.05), with a trend of decreasing prevalence with increasing age. No significant association was found between age and severity of astigmatism (P > 0.05). The prevalences of mild, moderate, and severe astigmatism were 6.51%, 3.11%, and 1.84%, respectively. Mild astigmatism was significantly more prevalent than moderate (P < 0.05) or severe astigmatism (P < 0.05). The prevalence of astigmatism differed significantly among the three orientations of axis (P < 0.001). The prevalences were 9.20%, 1.68%, and 0.57% for with-the-rule, against-the-rule, and oblique astigmatism, respectively. We found a statistically significant difference in the prevalences of astigmatism based on the axis orientation between boys and girls (P < 0.05) and between age groups (P < 0.001), with a decreasing trend observed with increasing age.
Conclusions: We found a prevalence of 11.46% for astigmatism among schoolchildren aged 6–16 years in Mumbai, India. There was a decreasing trend in prevalence with increasing age, with no difference between sexes. The prevalence was the highest for mild astigmatism, followed by moderate and severe astigmatism. Prevalence differed significantly based on the axis orientation among the three subtypes, age groups, and between the two sexes, with a decreasing trend with increasing age. With-the-rule astigmatism was the most common, followed by against-the-rule astigmatism; oblique astigmatism was the least common.
Intrapapillary vessel density using optical coherence tomography angiography in primary open-angle glaucoma and normal eyes
Amira M. Elgendy, Mohamed E. Shahin, Ahmed I Aboelenein, Moataz A. Sallam
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 2 (2024), 1 September 2024 , Page 63-69
https://doi.org/10.51329/mehdioptometry199
Background: Optical coherence tomography angiography (OCTA) is used to quantify optic nerve blood flow in patients with primary open-angle glaucoma (POAG). Intrapapillary vessel density (iVD) has a high diagnostic accuracy for differentiating healthy from glaucomatous eyes. We compared the iVD of patients with POAG with that of healthy controls in an Egyptian tertiary referral center.
Methods: This cross-sectional study consecutively recruited patients with medically controlled POAG and age- and sex-matched healthy individuals. All study participants underwent a detailed medical history evaluation and comprehensive ophthalmic examination, with recording of the cup-to-disc ratio (C/D ratio) and intraocular pressure (IOP). Humphrey visual field evaluation using the standard 24-2 program was performed and global indices, including mean deviation (MD) and pattern standard deviation (PSD), were extracted. OCTA and spectral-domain (SD) OCT images were obtained. Average thickness of the retinal nerve fiber layer (RNFL) and thicknesses in the superior, inferior, nasal, and temporal quadrants were recorded. OCTA imaging was used to measure vessel density, and the automatically processed data for iVD were extracted.
Results: We included 86 eyes, 43 in the POAG and 43 in the healthy control group, with male predominance in both groups and mean (standard deviation [SD]) ages of 42.1 (9.4) and 39.3 (9.6) years, respectively. The two groups were comparable in terms of mean age, sex ratio, laterality of the included eyes, and mean IOP (all P > 0.05). The mean (SD) C/D ratio, MD, and PSD were significantly higher in the POAG group than in the control group (all P < 0.01). The mean (SD) average RNFL thickness and RNFL thicknesses in the four quadrants were significantly less in glaucomatous eyes than in healthy control eyes (all P < 0.05). Eyes with POAG had a significantly lower mean (SD) iVD than healthy control eyes (P < 0.01). Linear regression analysis revealed a significant positive correlation between iVD and average RNFL thickness (r = + 0.52; P < 0.001) and a significant negative correlation between iVD and PSD (r = – 0.31; P = 0.042) in eyes with POAG.
Conclusions: The structural, vascular, and functional parameters measured in this study deteriorated in eyes with POAG compared to controls. Significant circumpapillary RNFL thinning correlated well with reduced iVD in eyes with POAG. Similarly, a lower iVD detected using OCTA had a significant inverse correlation with PSD in the perimetry of eyes with POAG. Further studies with additional parameters and longer follow-up periods are required to verify our preliminary findings.
Clinical characteristics and outcomes of band keratopathy: a 10-year retrospective analysis
Zeynep Akgun, Anil Kaplan, Melis Palamar, Sait Egrilmez, Ayse Yagci, Ozlem Barut Selver
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 2 (2024), 1 September 2024 , Page 70-75
https://doi.org/10.51329/mehdioptometry200
Background: Band keratopathy is a chronic, degenerative corneal disease resulting from gradual calcium deposition in the superficial cornea. Herein, we report the spectrum of causes, treatment outcomes, and recurrence rates of band keratopathy at a tertiary referral center throughout one decade.
Methods: This retrospective study included patients with clinical diagnoses of band keratopathy who were treated with combined ethylenediaminetetraacetic acid (EDTA) and superficial keratectomy with or without amniotic membrane transplantation (AMT). Patient medical records were reviewed, and detailed demographic and ophthalmological data, such as baseline and last follow-up best-corrected distance visual acuity (BCDVA), ocular or medical comorbidities, type of intervention, postoperative follow-up duration, relevant complications, and recurrence were recorded.
Results: A total of 32 eyes of 29 patients with 3 (10.3%) bilateral and 26 (89.7%) unilateral cases of treatment-requiring bank keratopathy were included. The mean (standard deviation [SD]) (range) age was 39.4 (22.4) (2–74) years, and most patients were female. The most common secondary cause was previous vitreoretinal surgery with silicone oil tamponade (15.6%); however, idiopathic cases were the most common (18.8%). Systemic comorbidities were present in 27.6% of patients, consisting of hypertension, diabetes mellitus, epilepsy, coronary artery disease, Behcet’s disease, and juvenile idiopathic arthritis; however, none of the patients had systemic diseases associated with hypercalcemia. Two of the 3 patients with bilateral involvement had chronic uveitis secondary to systemic rheumatological disease. The mean (SD) follow-up duration was 5.6 (4.0) years, and no serious postoperative complications occurred. The mean (SD) baseline and final BCDVA in logarithm of the minimum angle of resolution (logMAR) were 1.98 (1.0) and 1.7 (1.0), respectively (P > 0.05). Combined EDTA chelation and superficial keratectomy with and without AMT were performed in 12.5% and 87.5% of eyes, respectively. Recurrence was observed in 37.5% of eyes within the mean (SD) (range) follow-up of 9.4 (9.1) (1–32) months. Seven of the 12 eyes with recurrence underwent re-EDTA chelation combined with superficial keratectomy and AMT; however, 5 patients managed conservatively.
Conclusions: In this study, band keratopathy requiring intervention more commonly affected female individuals and was unilateral. Most cases were idiopathic. Systemic comorbidities were present in approximately one-third of cases. Managing band keratopathy using a combination of EDTA chelation and superficial keratectomy with or without AMT could be a potential treatment modality. Further large-scale studies are required to provide robust conclusions regarding the efficacy and safety of this management approach.
Retinal changes in preeclampsia
Pegah Rashidian, Roxana Safari, Seyyed Amirhossein Salehi, Shaghayegh Karami
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 2 (2024), 1 September 2024 , Page 76-84
https://doi.org/10.51329/mehdioptometry201
Background: The eye undergoes a series of physiological changes during pregnancy in response to metabolic and hormonal adaptation. Preeclampsia (PE) is the main cause of maternal morbidity and is associated with serious pregnancy-related complications. Characterized by hypertension and proteinuria, PE affects 2–8% of pregnancies globally. Previous studies have indicated that PE compromises retinal health. We examined the effects of PE on retinal structure and vasculature.
Methods: We conducted a literature review by searching PubMed/MEDLINE, Embase, and Scopus using terms pertaining to PE and the retina. The review included articles published between January 1, 1990, and May 30, 2024. The articles were selected based on their relevance to the topic. The key findings are summarized to offer a comprehensive overview of current knowledge, highlight the pathophysiology and manifestations of PE-related retinal changes, and propose clinical implications, diagnostic clues, and management strategies.
Results: PE is associated with visual disturbances caused by various retinal changes, including arteriolar narrowing, vasospasm, hemorrhages, exudates, serous retinal detachment, macular edema, retinal vein occlusion, and choroidal ischemia. These are mostly evident on fundus examination and frequently resolve postpartum. The underlying pathophysiology involves endothelial dysfunction, hypertension, inflammation, and coagulopathy. These retinal changes have immediate clinical implications and long-term risks, necessitating early detection, prompt multidisciplinary management, and close follow-up. Although most PE-associated retinal disturbances spontaneously resolve after the termination of pregnancy, one-third of patients are likely to experience long-lasting consequences
Conclusions: Visual disturbances may precede and portend the onset of PE. Early detection and prompt management will mitigate fetal and maternal morbidity and mortality. Understanding the underlying pathophysiology of PE-related retinal manifestations is crucial for optimal management, because the majority of manifestations are reversible. Although retinal changes secondary to PE typically resolves postpartum, some studies demonstrated that women with PE may have a higher long-standing risk of ocular disorders. A multidisciplinary team approach involving obstetricians, ophthalmologists, and healthcare providers is essential for the immediate and long-term management of ocular consequences in pregnancy. Consequently, additional studies associated with robust methodologies are required to develop clinical guidelines.
Ocular toxocariasis masquerading as toxoplasmosis: a case report and literature review
Jinghua Chen, Sarah Madison Duff, Frances Saccoccio, Nausheen Khuddus, Nazanin Ebrahimiadib, Gibran Syed Khurshid
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 2 (2024), 1 September 2024 , Page 85-92
https://doi.org/10.51329/mehdioptometry202
Background: False-negative and false-positive results in Toxoplasma serology are possible, and this could be misleading. Here, we report the case of a boy with Toxocara-associated panuveitis who was initially treated for toxoplasmosis owing to false-positive Toxoplasma immunoglobulin M (IgM) serology.
Case Presentation: A nine-year-old boy presented with intermittent headaches and blurred vision in the left eye. Close contact with domesticated animals was remarkable in the patient’s history. Upon examination, vision was 20/400 in the left eye. Slit-lamp examination revealed anterior chamber cells and flare without keratic precipitates, with vitreous cells and veils, optic disc edema, and a blurred fundus appearance. A systemic investigation revealed the presence of anti-Toxoplasma IgM antibodies. Treatment was initiated using topical cycloplegic and corticosteroid eye drops, in addition to oral trimethoprim/sulfamethoxazole. Oral corticosteroids were also administered. As the inflammation resolved, an inferior tractional detachment was detected on fundus examination, leading to the ultimate diagnosis of ocular toxocariasis. An enzyme-linked immunosorbent assay was positive for serum Toxocara antibodies. A fourteen-day course of oral albendazole was ordered by the pediatric infectious disease service because of the concern for visceral larva migrans, while topical eye drops were continued and oral prednisone was tapered. One month later, visual acuity in the left eye had improved to 20/70. The anterior chamber inflammation resolved; however, some vitreous cells and optic disc edema persisted. The inferior tractional detachment was much better visualized, and a peripheral granuloma was observed. Four months later, without any oral or topical medications, the patient’s visual acuity had improved to 20/30 and his eye had no active inflammation. The patient has been followed up for two years and has never developed any other lesions.
Conclusions: False-positive results on Toxoplasma serology and diffuse vitritis from toxocariasis that limited retinal visualization complicated the initial diagnosis in this case. In diagnosing the etiology of uveitis, ocular examination and detailed history taking should be emphasized, as laboratory results may be misleading.
Spring 2024
Vol. 5 No. 1 (2024)
Impact of patching treatment on quality of life among children with amblyopia in Gaza Strip, Palestine
Asmaa H. Eslayeh, Norliza Md Fadzil, Rokiah Omar
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 1 (2024), 30 April 2024 , Page 1-9
https://doi.org/10.51329/mehdioptometry191
Background: Eye patching treatment affects the health-related quality of life of children with amblyopia. However, the extent of this effect in Gazan children with amblyopia remains unknown. This study evaluated the effect of patching on the health-related quality of life in Gazan children with unilateral or bilateral refractive amblyopia.
Methods: This cross-sectional study was conducted at Gaza Ophthalmic Hospital, Gaza Strip, Palestine, from September 2019 to October 2020 with adherence to the standard operating procedures of the coronavirus pandemic. Children with refractive amblyopia who completed patching therapy with a successful outcome were recruited. After patching therapy was completed, the parents completed an 18-item parental Amblyopia Treatment Index (ATI) questionnaire via telephone.
Results: Twenty-four children having 36 eyes with refractive amblyopia and a mean (standard deviation) age of 7.6 (1.8) years were included. Children underwent 2 h or 2–6 h of daily patching for 12 or 17 weeks. The mean values for total ATI score, adverse effects subscale, difficulty with compliance subscale, and social stigma subscale were 2.6, 2.6, 2.7, and 2.9, respectively, indicating that part-time patching was mostly accepted and had less impact on health-related quality of life. Treatment compliance was high; children complained at the time of patch application but did not pay attention to the patch once it was in place. In most children, the patch caused no adverse effects related to physical activities such as fun activities, learning, writing or drawing, visualizing, or playing with toys. Social stigma due to patch complications or different perceptions was not a concern. However, the perceptions of others were a major concern (n = 19, 79.2%). No significant association was found between the overall ATI score or the score of any of the subscales (adverse effects, difficulty with compliance subscale, or social stigma) and the child’s age, sex, number of lines improved in visual acuity of the amblyopic eye, severity of amblyopia, laterality, or treatment period (all P > 0.05).
Conclusions: The ATI questionnaire score and its three subscales revealed that the quality of life among Gazan children with refractive amblyopia was less affected by the part-time patching treatment. In the future, the ATI questionnaire could be used with various treatment modalities and types of amblyopia in the same setting to provide more practical guidelines on the management of amblyopia.
Contrast sensitivity assessment using the Mars letter contrast sensitivity test
Onoja Peter Okwori, Kato Chaha, Abdu Lawan, Ugochukwu Anthony Eze
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 1 (2024), 30 April 2024 , Page 10-17
https://doi.org/10.51329/mehdioptometry192
Background: Contrast sensitivity (CS) represents an individual’s ability to detect differences in luminance between two areas and is an essential component of vision. Various studies have evaluated the relevance of different charts to assess CS in ophthalmology practice. We evaluated the CS of healthy individuals using the Mars letter CS chart.
Methods: In this hospital-based cross-sectional study, we consecutively recruited healthy individuals older than 18 years with unremarkable ocular examinations who attended the general outpatient clinic at Benue State University Teaching Hospital, Makurdi, Nigeria, between March 2021 and July 2021. Each participant was allocated to one of five groups with 10-year age intervals and 1:1 male-to-female ratios. All participants underwent a detailed ophthalmic examination. We tested visual fields using the 24-2 program on a Humphrey visual field analyzer with appropriate refractive correction. Monocular testing of CS with appropriate spectacle correction was performed using a Mars letter CS chart. The tribe, age, and sex of each individual, along with the best-corrected visual acuity (BCVA), intraocular pressure, mesopic pupil size, cup-to-disc ratio (C/D ratio), and mean deviation (MD) of the visual field for each eye were recorded.
Results: A total of 100 eyes of 50 patients with a mean (standard deviation [SD]) age of 44.6 (12.8) years and a 1:1 male-to-female ratio were enrolled. The mean (SD) CS score for the 100 included eyes was 1.67 (0.09) log units. The mean (SD) CS score was comparable between sex groups and tribes (both P > 0.05) yet differed significantly between age groups (P < 0.001). We found a significant good inverse correlation between CS score and age (r = – 0.60; P = 0.001), a low inverse correlation with BCVA (r = – 0.29; P < 0.003), and a low direct correlation with C/D ratio (r = + 0.23; P = 0.023); however, we observed no significant correlation with tribe (r = + 0.07; P = 0.053), sex (r = + 0.16; P = 0.123), IOP (r = + 0.07; P = 0.481), mesopic pupil size (r = – 0.02; P = 0.861), and mean deviation of visual field (r = + 0.02; P = 0.873).
Conclusions: We observed a progressive decline in the mean CS score in healthy eyes with each decade of increase in age. Our findings are similar to those of previous studies and could be used as reference values for the healthy population among various age groups. However, further studies with larger sample sizes are necessary to encourage clinicians to incorporate CS into routine examinations. Further studies must compare these normative values with those of disease conditions to further understand the clinical application of the CS test.
Clinical characteristics, etiologies, co-injuries, and visual outcomes of eyelid lacerations
Emin Serbulent Guclu, Omer Ozer, Pinar Eroz
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 1 (2024), 30 April 2024 , Page 18-24
https://doi.org/10.51329/mehdioptometry193
Background: Eyelid trauma may be accompanied by open globe injury, canalicular injury, hyphema, angle recession, or retinal detachment. Therefore, a detailed assessment should be performed during the associated ophthalmological examinations. We assessed the demographic and clinical characteristics, etiologies, co-injuries, and visual outcomes in patients with eyelid lacerations.
Methods: This retrospective, cross-sectional study included individuals 18 years of age and older who underwent repair of an eyelid injury at our tertiary referral center between January 2021 and March 2023. Patients with known structural eyelid disorders or previous ocular surgery were excluded. Demographic and clinical data, including injury site and type, mechanism of injury, and presence of additional ocular injuries, were noted. Best-corrected visual acuity (BCVA) was recorded as the logarithm of the minimum angle of resolution (logMAR) notation at the initial and final follow-up visits.
Results: Of 195 included patients with a mean (standard deviation [SD]) age of 42.5 (5.6) years, 164 (84.1%) were men. The most common etiology was accidental (n = 70, 35.9%) and almost half of these injuries occurred at the workplace (n = 32 out of 70, 45.8%). Nine patients (4.6%) had no co-injury, 47 (24.1%) had imaging evidence of orbital bone fractures, 25 (12.8%) had nasolacrimal system involvement, and 11 (5.6%) had an open globe injury. The right upper eyelid (n = 62, 31.8%) was the most commonly affected site. Tissue loss was observed in 77 (39.5%) patients; however, no grafting was required. Five patients (2.6%) underwent lateral canthotomy to improve tissue apposition. On initial examination, 24 patients (12.3%) had traumatic myogenic ptosis, 13 (6.7%) had traumatic aponeurotic ptosis, and ptosis persisted in 7 of these 37 patients (18.9%) 6 months after laceration repair. We observed significant improvement in BCVA at the final follow-up visit (P < 0.001); at the preoperative and final visits, mean (SD) BCVA measurements were 0.21 (0.15) and 0.12 (0.07) logMAR, respectively.
Conclusions: Eyelid injuries are more common in men, and the most common etiology is accidental. These injuries occur most commonly in the workplace. Isolated eyelid lacerations are rare. Early ocular assessment and prompt management ensure better visual outcomes. We recommend preventive safety precautions for workplaces to reduce the incidence of avoidable injuries. Identifying risk factors in further population-based studies could prevent loss of labor in a productive population. Further multicenter, nationwide, longitudinal studies could estimate the actual burden and prognosis of ocular trauma, particularly that of eyelid lacerations.
Sustaining private eye care practices during initial days of the coronavirus pandemic
Srinivasan Sanjay, Arushi Garg, Naren Shetty, Rohit Shetty
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 1 (2024), 30 April 2024 , Page 25-34
https://doi.org/10.51329/mehdioptometry194
Background: The coronavirus disease 2019 (COVID-19) pandemic created new challenges for private eye care practices. Safety issues were encountered by both the healthcare workers and patients. This short communication addresses the changes made in our private eye care practice during the pandemic and the valuable lessons learned for the future.
Methods: We describe the challenges faced at our tertiary private eye care practice in India with respect to treating patients and preventing the transmission of COVID-19, considering the economic hardship within this area. We discuss the emerging economic, medical, legal, educational, and psychological issues and their solutions, which eye care hospitals could follow in the future to ensure safety without compromising quality of care.
Results: Eye hospitals required efficient operation with reduced fixed expenses. Clinical practices were followed in the hospital as per the recommendations of the country’s apex ophthalmic body. Proper triage and prescreening of patients at the entrance, digitalization, teleophthalmology, staggered appointments, and role-appropriate personal protective equipment were important preventive measures. The operating room protocols were modified to ensure the safety of the operating staff. Special consent was obtained from patients to safeguard against legal repercussions arising from the pandemic. The training of residents and fellows led to new avenues, including the use of digital tools. Hospitals attempted to provide counseling and psychological support to their doctors and staff during these trying times.
Conclusions: The COVID-19 pandemic will not be the last pandemic to occur in an ever-changing world. This event provided us with many new insights into the economic, clinical, legal, and psychological challenges of the COVID-19 pandemic and with ways to overcome these challenges and emerge intact. Clinical and surgical training suffered during the pandemic; however, the impact was only temporary. Clinical research gained respect because of the efforts undertaken during the pandemic. The pandemic was exceptionally harsh on many private eye care practices, and we hope to provide useful and comprehensive solutions on how to successfully navigate a similar situation if encountered in the future.
Pregnancy and diabetic retinopathy
Pegah Rashidian
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 1 (2024), 30 April 2024 , Page 35-42
https://doi.org/10.51329/mehdioptometry195
Background: An increase in the worldwide prevalence of diabetes, especially among younger populations, has led to a higher prevalence of pre-existing diabetes among pregnant women. The precise mechanisms underlying the development or progression of diabetic retinopathy (DR) during pregnancy are not entirely understood. This narrative review incorporates all available data to offer fresh insights into the pathogenesis and mechanisms of the pregnancy-induced development and/or progression of DR. Moreover, the author aims to offer clinical recommendations for DR both before conception and during pregnancy to appropriately counsel these susceptible patients.
Methods: A literature search was performed using various combinations of the following keywords: diabetes, pregnancy, diabetic retinopathy, ocular, eye, retina, microangiopathy, mechanism, pathophysiology, hyperglycemia, hypoxia, neovascularization, growth factors, immune system, blood flow, and recommendations. The search was conducted using PubMed/MEDLINE, ISI Web of Science, Scopus, and Google Scholar, and only English articles published from January 1, 2020, to December 31, 2023, involving human participants, were considered. The International Diabetes Federation Diabetes Atlas website was searched for clinical recommendations.
Results: Pregnancy-induced hyperglycemia, blood flow changes, growth factors, and the immune system play important roles in the development and progression of DR. Hyperglycemia leads to significant stress on the capillary endothelium through increased glucose flux via the polyol and hexosamine pathways, activation of protein kinase C, and increased formation of advanced glycation end-products. These pathways act in several ways that may lead to increased oxidative stress, inflammation, and vascular blockage. Thus, eye examinations are crucial before, during, and up to 12 months after pregnancy. Individuals with severe non-proliferative and proliferative DR should gradually decrease their blood glucose levels to near-normal levels over a period of 6 months before conception. Statins and medications inhibiting the renin–angiotensin system should be discontinued before pregnancy or at the initial antenatal visit if they are still being used. Retinal examinations should be performed shortly after conception and during the first trimester using tropicamide eye drops and digital imaging. Subsequent examinations should be scheduled based on DR severity at the initial examination.
Conclusions: While the precise mechanism underlying the progression of DR during pregnancy remains uncertain, the available literature suggests that pregnancy-induced hyperglycemia, blood flow changes, growth factors, and the immune system play important roles in its development and progression. Pregnant women with diabetic eye manifestations benefit from the expertise of multidisciplinary teams comprising ophthalmologists, diabetologists, and gynecologists to improve both maternal and perinatal outcomes. Moreover, postpartum follow-up requires special attention.
Slowing myopia progression in children
Ehab Ghoneim, Gehad El Deeb, Ahmed A Hassaan
Medical hypothesis, discovery & innovation in optometry, Vol. 5 No. 1 (2024), 30 April 2024 , Page 43-50
https://doi.org/10.51329/mehdioptometry196
Background: A large proportion of individuals develop myopia, which is recognized as a global health concern and is predicted to increase in prevalence. Long-term eye problems are associated with myopia, particularly in young individuals. Retinal detachment and choroidal degeneration are among the causes of visual impairments associated with myopia. In this narrative review, we summarized the current measures for slowing myopia progression in children, including their safety profiles and potential drawbacks.
Methods: We conducted an English literature search for articles published between January 1, 2000, and October 31, 2023, using various combinations of keywords related to myopia, myopia progression, childhood myopia, myopia control, atropine, orthokeratology, and contact lenses. We included original or review articles pertaining to lifestyle changes and pharmacological, optical, or laser interventions for managing myopia progression in children. Our search was conducted using PubMed/MEDLINE, Google Scholar, and the Wiley Online Library. We reviewed the full text of included articles and qualitatively summarized the results of relevant studies using a narrative synthesis approach.
Results: Multiple meta-analyses indicated that increased outdoor time is associated with a lower myopia prevalence, with each extra hour spent outside each week reducing the risk of myopia by 2%. Candidate drugs, such as atropine, pirenzepine, and 7-methylxanthine, and certain intraocular pressure-lowering medications, such as timolol, have been studied in human trials for their ability to manage myopia. The nonselective antimuscarinic drug atropine, followed by the M1-selective antimuscarinic drug pirenzepine, displayed positive results in slowing myopia. Oral 7-methylxanthine, a nonselective adenosine receptor antagonist, reduces axial myopia caused by hyperopic defocus in a primate model. Low-intensity laser therapy using low doses of red and near-infrared light, visual biofeedback training, bifocal or multifocal spectacles, orthokeratology using a rigid gas-permeable contact lens, combined orthokeratology and atropine, soft contact lenses with a central distance zone and higher positive power in the periphery, and peripheral defocus contact lenses are among the interventional therapies with promising results in managing myopia progression in children.
Conclusions: The current literature supports the efficacy of increased outdoor time, administration of pharmacological agents, and special contact lenses as treatment modalities for slowing myopia progression in children. The effectiveness of orthokeratology alone and in combination with topical atropine therapy has also been assessed. Further research is needed to pinpoint the precise mechanisms of action of these therapies and to determine the best course of treatment. The increasing global prevalence of childhood myopia necessitates robust interventional studies into slowing myopia progression and preventing high myopia and related sight-threatening conditions in adulthood.
Winter 2023
Vol. 4 No. 4 (2023)
Rhegmatogenous retinal detachment: an analysis of 2315 eyes over a six-year period
Farzan Kianersi, Yousef Barati, Hamidreza Kianersi, Heshmatollah Ghanbari, Hasan Razmjoo, Farhad Fazel, Alireza Dehghani, Mohammadreza Akhlaghi, Ali Salehi, Hanieh Kianersi, Mohsen Pourazizi
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 4 (2023), 25 December 2023 , Page 148-156
https://doi.org/10.51329/mehdioptometry185
Background: Rhegmatogenous retinal detachment (RRD) is a form of retinal detachment caused by passage of fluid from the vitreous cavity into the space between the neurosensory retina and the retinal pigment epithelium via a retinal break or full-thickness defect. At our tertiary referral center, we evaluated the clinical and epidemiological features of RRD, and we herein report the frequency of related risk factors.
Methods: In this retrospective study, we reviewed the records of patients with a final diagnosis of RRD at an academic ophthalmological referral center in Isfahan, Iran, over a six-year period. We retrieved and reviewed data from the medical records of all eligible participants, including sex, age, laterality, lens status, macular status, type of RRD, location and number of breaks, type of surgery, rate of re-operation during the first year after initial surgery, and documented clinical risk factors for RRD. Clinical risk factors were categorized as the presence of myopic refractive error, ocular trauma, history of cataract surgery, history of other ocular surgeries, history of uveitis, or undetermined.
Results: We included 2315 eyes of 2229 patients with a mean (standard deviation [SD]) age of 51.1 (16.9) years and a male-to-female ratio of 1.8:1. The most common quadrants containing retinal breaks were the superotemporal quadrant (34.1%), inferotemporal quadrant (23.4%), and superonasal quadrant (10.7%). Macula-involved RRD was seen in 90% of eyes (n=2083 eyes). The most frequently identified risk factors were cataract surgery (32.9%) and myopia (22.3%) in adults, and myopia (35.0%) and ocular trauma (27.4%) in the pediatric group. Most eyes underwent pars plana vitrectomy (51.3%), whereas pneumatic retinopexy (0.7%) was the least commonly selected.
Conclusions: Our results indicate that cataract surgery and myopia are the most common risk factors for RRD in adults. Myopia and ocular trauma are the most common risk factors in pediatric patients. As observed in many studies, the characteristics of the study population, including middle age, male sex, myopia, and ocular trauma, may be associated with RRD at different rates. Further population-based longitudinal studies with larger sample sizes are required to verify these preliminary observations.
Contralateral eye comparison of the efficacy and safety of two artificial tear formulations for corneal subbasal nerve fiber regeneration after photorefractive keratectomy
Noor Shazana Md Rejab, Mohd Radzi Hilmi, Khairidzan Mohd Kamal, James S Wolffsohn
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 4 (2023), 25 December 2023 , Page 157-165
https://doi.org/10.51329/mehdioptometry186
Background: Currently, artificial tears (ATs) are the first-line agents for managing dry eye disease (DED). This study compared the efficacy and safety of two different AT formulations, Systane® Hydration (SH) and Systane® Ultra (SU), on symptoms of DED and regeneration of the subbasal corneal nerve fiber length (CNFL) in photorefractive keratectomy (PRK)-treated eyes.
Methods: This prospective contralateral comparative study recruited myopic eyes scheduled for PRK, and either SH or SU were administered for up to 3 months postoperatively. All participants underwent a standard comprehensive preoperative ophthalmological examination, in vivo confocal microscopy to evaluate the subbasal CNFL, and completed Ocular Surface Disease Index (OSDI) questionnaire for assessing dry eye symptoms. Image analysis software was used to calculate the subbasal CNFL (micrometer/mm2). Assessments were repeated at the 1- and 3-month follow-up visits. Pre- and postoperative subbasal CNFL and OSDI scores were compared to determine inter- and intra-group differences.
Results: Fifty eyes of 25 participants were included in this study. The mean (standard deviation) age of the participants was 22.7 (3.8) years. The OSDI scores for both groups increased significantly at 1 month (both P<0.05), followed by a decrease at 3 months to values comparable to the preoperative scores (both P>0.05). Although OSDI scores were comparable at baseline and at the 1-month postoperative visit (both P>0.05), the SU-treated eyes had a significantly better OSDI score at the 3-month visit (P<0.05), despite being clinically insignificant. Preoperative subbasal CNFL differed significantly between the groups (P=0.001), yet the mean values at both postoperative visits were comparable (both P>0.05). In both groups, subbasal CNFL was significantly reduced at 1 month, followed by a significant increase at the 3-month postoperative visit compared to baseline (all P<0.05). No treatment-related complications were observed at the end of the study period.
Conclusions: No significant difference was found between the preoperative and 3-month postoperative OSDI scores in the SH- or SU-treated eyes. Subbasal CNFL regeneration indicated a positive effect of both ATs, with a longer mean CNFL noted in the SH-treated eyes at the final visit. This suggests that SH may be a better option for improving corneal reinnervation after PRK. These observations must be verified in further trials with longer follow-up periods and larger sample sizes.
Effects of repeated intravitreal bevacizumab administration on anterior segment parameters and limbal stem cells
Mojtaba Eidizadeh, Mohsen Felegary, Seyed Hamid Madani, Fatemeh Hosseini, Masood Bagheri
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 4 (2023), 25 December 2023 , Page 166-173
https://doi.org/10.51329/mehdioptometry187
Background: Macular edema (ME) is fluid accumulation in the macula caused by vascular leakage. Repeated intravitreal bevacizumab (IVB) injections are extensively used to treat ME of different origins, are well tolerated, and have few side effects. This study evaluated the effects of repeated IVB injections on the anterior segment parameters and limbal stem cells (LSCs) in eyes with ME.
Methods: This before–after study involved patients with ME of different causes who underwent repeated IVB injections at the Imam Khomeini Ophthalmology Center in Kermanshah, Iran. Before and after repeated IVB injections, anterior segment parameters were measured using anterior segment optical coherence tomography, and the LSCs were assessed using impression cytology.
Results: We enrolled 42 eyes of 42 patients with a mean (standard deviation [SD]) age of 59.6 (7.6) years, of whom 25 (59.5%) were men and 17 (40.5%) were women. The underlying diseases included diabetic ME in 30 eyes (71.4%), central (5 [11.9%]) or branch (3 [7.1%]) retinal vein occlusion, and choroidal neovascularization in 4 eyes (9.5%). The right eye was affected in 22 (52.4%) participants. The mean (SD) number of IVB injections was 4.3 (1.3). After repeated injections, the mean central corneal thickness (CCT) increased, whereas the mean anterior chamber angle (ACA) and anterior chamber depth (ACD) decreased (all P<0.001). Three patients developed LSC deficiency after repeated IVB injections for diabetic ME.
Conclusions: We observed a significant increase in the mean CCT and a decrease in the mean ACA and ACD after repeated IVB injections in our series. Three patients developed LSC deficiency after repeated IVB injections for diabetic ME management. The observed effect on LSC may cast doubt on the safety of repeated IVB injections; however, this finding must be verified in multicenter clinical trials with longer follow-up periods and larger study samples.
Association of WDR36 polymorphisms with primary open-angle glaucoma
Pragati Garg, Mehvish Malik, Tasleem Raza
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 4 (2023), 25 December 2023 , Page 174-180
https://doi.org/10.51329/mehdioptometry188
Background: Various genes contribute to the pathophysiology of primary open-angle glaucoma (POAG). The WD repeat domain 36 (WDR36) gene may participate in T cell activation and, hence, in the pathogenesis of POAG. We investigated the association of two WDR36 gene single nucleotide polymorphisms (SNPs) with POAG.
Methods: This cross-sectional study recruited patients aged >40 years with POAG and investigated the rs10038177 and rs1971050 SNPs of WDR36 using polymerase chain reaction and direct DNA sequencing. All participants underwent comprehensive ocular examination, visual field assessment using the Swedish Interactive Threshold Algorithm standard 24-2 threshold test, and measurement of peripapillary retinal nerve fiber layer thickness (RNFLT) using spectral domain optical coherence tomography.
Results: We enrolled 105 patients with a mean (standard deviation) age of 55.41 (8.56) years and a male-to-female ratio of 56 (53.3%) to 49 (46.7%), most of whom had a diagnosis of POAG for 2 to 5 years (60.0%). Most participants had diabetes (90.5%) but not hypertension (88.6%). There was a significant association of rs10038177 (P<0.05), but not rs1971050 (P>0.05), with family history of glaucoma. The association between rs10038177 and intraocular pressure was significant (P<0.05), but that between rs1971050 and intraocular pressure was not (P>0.05). No significant association was observed between mean cup-to-disc ratio and either SNP (both P>0.05). For rs10038177, a significant association was found only with the RNFLT of the superior quadrant (P<0.05), whereas for rs1971050, a significant association was found with the RNFLT of all four quadrants and average RNFLT (all P<0.05). However, pairwise comparisons revealed no significant differences between genotypes (P>0.05 for all pairwise comparisons). The association of rs10038177 with glaucoma severity was insignificant (P>0.05), and most patients with the TC genotype (71.7%) had moderate severity. There was no significant association between rs1971050 and glaucoma severity (P>0.05).
Conclusions: We observed genetic links between some, but not all, characteristics of POAG and the rs10038177 and rs1971050 SNPs of WDR36. Follow-up studies on these and other WDR36 SNPs in populations with different genetic backgrounds are necessary to confirm this genetic association.
Photophysical and photodynamic analysis of different formulations of riboflavin
Matias Osaba, Tomas Cristian Tempesti, Victor Eduardo Reviglio
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 4 (2023), 25 December 2023 , Page 181-187
https://doi.org/10.51329/mehdioptometry189
Background: Riboflavin (Rb) has been used in the ophthalmological procedure known as corneal cross-linking (CXL). Pathologies requiring this treatment include keratoconus, corneal ectasia, and infectious keratitis. Rb is instilled via different molecules that are transported into the tissues. However, each vehicle imparts different properties that alter the photodynamic behavior of Rb, leading to variable concentrations of free radicals within the medium. The objective of this study was to measure the concentrations of free radicals produced by commonly used Rb formulations. To determine the free radical production level of each formulation, L-tryptophan (L-Tryp) was used as a model substrate because it can be efficiently photo-oxidized.
Methods: We investigated the photodegradation of L-Tryp and its kinetics upon light exposure. The spectra were recorded using a Shimadzu UV-1800 PC spectrophotometer and a Cary Eclipse fluorescence spectrophotometer. A high-power solid-state LED light source was used for irradiation. L-Tryp degradation was performed using a 9-W LED lamp, and steady-state photolysis was conducted in quartz cells. The observed rate constants for L-Tryp degradation were determined by analyzing the changes in absorbance and fluorescence intensity. Data analysis was performed using Origin software.
Results: We examined the characteristics of the photophysical and photodynamic action of the carriers in different commercially available Rb formulations. These included a) Rb with dextran, b) Rb without dextran, c) VibeX Rapid® (hydroxypropylmethylcellulose as a vehicle), d) Trans-Epithelial Kit (I) (sodium chloride as a vehicle), and e) Trans-Epithelial Kit (II) (benzalkonium chloride as a vehicle), using L-Tryp as a model substrate, and focusing on absorption and emission spectra. VibeX Rapid® exhibited the highest photo-degradation constant. The study affirmed the stability of Rb formulations for CXL and highlighted the efficacy of VibeX Rapid® in L-Tryp photo-oxidation and this rationalizes its current use as a CXL agent.
Conclusions: We demonstrated that formulations for transport of Rb are of crucial importance in CXL applications. Rb in the VibeX Rapid® formulation is more effective in generating photo-degradation, and this reflects its superior performance in CXL. Future experiments should be designed and conducted to quantitatively differentiate the production of free radicals. Studies involving human participants could shed light on the clinical efficacy and safety of the available Rb formulations.
Hypothetical proposal for the course of retinal blood vessels in the posterior pole—description and its clinical implications
Pradeep Venkatesh
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 4 (2023), 25 December 2023 , Page 188-194
https://doi.org/10.51329/mehdioptometry190
Background: Branch retinal vein occlusion (BRVO) is the second-most common retinal vascular disorder. Arteriosclerotic changes at the site of obstruction and hemodynamic turbulence within the vessels are considered risk factors. Overcrossing of the vein by an artery has traditionally been considered to increase the risk of BRVO. Recent studies using optical coherence tomography and optical coherence tomography angiography have suggested a higher prevalence of vein-over-artery crossings in this disease. Nevertheless, uncertainty persists as to why some patients, even those with the same disease duration, have varying degrees of venous dilation and develop sufficient collaterals, while others develop substantial ischemia and its sequelae.
Hypothesis: Herein, it is hypothesized that because retinal blood vessels are transparent, tubular, and collapsible conduits coursing over a hollow spherical surface, the changes related to AV crossings over the entire course of a vessel, rather than at any single isolated crossing, could contribute to the risk, natural progression, and outcomes of BRVO. The study analyzed color fundus photographs from two image datasets. The first dataset comprised 100 randomly selected images from the author’s own collection at the Rajendra Prasad Center for Ophthalmic Sciences. The second dataset comprised 100 images from the MESSIDOR database; three images were excluded owing to poor focus. Using 394 observations from 197 retinal photographs, four distinct patterns of AV crossing along the course of blood vessels were recognized: (A and B) wicker basket, (C) straight, (D) widely spaced, and (E) indeterminate. The percentages of tight wicker, loose wicker, straight, widely spaced, and indeterminate patterns in the two image sets were 19% (38/200) and 16.5% (32/194), 22.5% (45/200) and 27.8% (54/194), 16.5% (33/200) and 15.5% (30/194), 22.5% (45/200) and 28.4% (55/194), and 19.5% (39/200) and 11.9% (23/194), respectively. Hence, the wicker basket pattern was the most common AV crossing pattern in both image sets.
Conclusions: The wicker basket pattern may provide structural stability and aid in maintaining pressure gradients within the retinal vascular bed. This observation of variable AV relationships at consecutive crossings may improve our understanding of the pathogenesis, natural history, and outcomes of BRVO. Future longitudinal studies including patients at risk of BRVO, or retrospective analyses of patients with BRVO who had ophthalmic examinations and archived fundus images before the vascular event, should verify the relevance of these observed vascular patterns.
Fall 2023
Vol. 4 No. 3 (2023)
Immediate effects of artificial tears with and without preservatives containing hyaluronic acid and carboxymethyl cellulose
Fatin Amalina Che Arif, Mohd Radzi Hilmi, Noor Shazana Md Rejab, James S Wolffsohn
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 3 (2023), 3 October 2023 , Page 102-111
https://doi.org/10.51329/mehdioptometry179
Background: Currently, hyaluronic acid (HA) and carboxymethyl cellulose sodium (CMC) are common polymers incorporated in artificial tears (ATs). The aim of the present study was to evaluate the immediate effect of preservative- and preservative-free HA- and CMC-containing ATs on tear-film parameters and determine patient preference after AT instillation.
Methods: In this prospective, double-blind, randomized, comparative study, we assessed fluorescein tear break-up time (TBUT), bulbar redness, and tear ferning pattern (TFP) up to 60 min after the instillation of ATs with and without preservatives containing HA and CMC in the recruited participants. To test patient preference, each patient was administered with the Ora Calibra™ Ocular Discomfort and 4-Symptom Questionnaire (OOD4SQ; scale of 0–5) before and 60 min after the instillation of ATs. The selection of 14 descriptive words based the 11-point Ora Calibra™ Drop Comfort Scale (ODCS; scale of 0–10) was administered immediately after instillation of each AT to test the drop comfort score.
Results: We enrolled 200 eyes of 200 patients, including 163 (81.5%) women and 37 (18.5%) men, with a mean (standard deviation) age of 28.38 (5.42) years. Immediately or 5, 15, or 60 min after the instillation, the mean TBUT did not differ by presence of preservatives, HA, or CMC (all P > 0.05). However, it was significantly higher 5-min post-instillation compared to baseline and significantly lower 15- and 60-min post-instillation (all P < 0.05). The mean grade of bulbar redness immediately or 3, 5, 15, or 60 min after instillation did not differ by presence of preservatives for HA or CMC containing ATs (all P < 0.05). It did not differ significantly 3-, 5-, 15-, or 60-min post-instillation compared to baseline (all P > 0.05). The mean drop comfort scale after the instillation of ATs did not differ significantly by presence of preservatives, HA, or CMC (all P < 0.05). Positive descriptive words were selected by a higher proportion of participants in both groups. According to OOD4SQ, the overall discomfort and mean dryness scores improved significantly after instillation of HA-containing ATs (both P < 0.05), while the mean burning sensation, grittiness, and stinging scores remained unchanged (all P > 0.05). The overall discomfort and mean scores for each ocular symptom (P < 0.05), except for stinting (P > 0.05), improved significantly after instillation of CMC-containing ATs. The TFP did not change significantly from baseline to 60 min after the instillation of any AT (P > 0.05).
Conclusions: Both ATs with and without preservatives containing HA and CMC produced positive short-term objective and subjective effects. However, TBUT, TFP, bulbar redness, and patient feedback were comparable for both HA- and CMC-containing ATs. Further trials with longer observation periods or the recruitment of patients with different severities of dry eye could provide more robust and clinically applicable conclusions.
Refractive errors in infants with retinopathy of prematurity treated using laser or anti-vascular endothelial growth factor monotherapy
Tayyebeh Davabi, Afsar Farahani, Mohamad Ghasemi Broumand, Elham Ashrafi, Mehdi Yaseri
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 3 (2023), 3 October 2023 , Page 112-120
https://doi.org/10.51329/mehdioptometry180
Background: Infants treated for retinopathy of prematurity (ROP) could develop visually significant refractive errors. In this study, we report pre-treatment refractive errors in premature infants with treatment-requiring ROP treated using laser or anti-VEGF monotherapy and compare the components of post-treatment refractive error values between the two treatment groups at different follow-up timepoints.
Methods: In this retrospective cohort study, we analyzed 360 eyes of 181 premature infants with treatment-requiring ROP who were referred to Farabi Eye Hospital, Tehran, Iran between March 2020 and April 2021. Of the 360 eyes, 195 received laser monotherapy (laser treatment group) and 165 received an intravitreal anti-VEGF injection (anti-VEGF therapy group). All included eyes underwent pre- and post-treatment cycloplegic refraction. Cycloplegia was induced for each infant by instilling a mixed eye drop containing 1% tropicamide, 2.5% phenylephrine, and 0.5% tetracaine (in equal volumes) in each eye three times at five-minute intervals. Cycloplegic refraction was performed 30 minutes after the third instillation.
Results: The mean (standard deviation [SD]) gestational age (GA) and birth weight (BW) of the infants were 29.0 (2.0) weeks and 1241.0 (403.0) g, respectively. The male-to-female ratio in the entire study cohort was 107 (59.1%) / 74 (40.9%), whereas the ratios in the anti-VEGF therapy group and laser treatment group were 47 (56.6%) / 36 (43.4%) and 60 (61.2%) / 38 (38.8%), respectively. The pre-treatment assessment revealed that 218 (60.6%) eyes were hyperopic, 112 (31.1%) were myopic, and 30 (8.3%) were emmetropic. In the anti-VEGF therapy group, 87 (52.7%) eyes were hyperopic, 63 (38.2%) were myopic, and 15 (9.1%) were emmetropic. In the laser treatment group, 131 (67.2%) eyes were hyperopic, 49 (25.1%) were myopic, and 15 (7.7%) were emmetropic. The mean (SD) spherical refractive error and spherical equivalent of refractive error (SEQ) at the 1-week, 1-month, and > 6-month post-treatment follow-up timepoints; the mean cylindrical refractive error at the 3-month post-treatment timepoint; and the mean SEQ at the time of ROP regression were significantly different between the treatment groups (all P < 0.05). The rate of anisometropia increased significantly from 3.4% at baseline to 9.2% at the 6-month post-treatment follow-up timepoint (P < 0.05).
Conclusions: In this study, the most common pre-treatment refractive status of all included eyes with treatment-requiring ROP and eyes in each treatment group was hyperopia, followed by myopia and emmetropia. At the more than 6-month post-treatment follow-up, cycloplegic refraction revealed that the laser-treated eyes were significantly more hyperopic than the anti-VEGF-treated eyes, a finding similar to the pre-treatment refraction results. Further studies of same cohort with a longer follow-up period and a control group are needed to determine the real-world effect of each treatment modality on the refractive statuses of children treated for ROP.
Outcomes of orbital decompression for thyroid eye disease over a 10-year period at a tertiary eye care referral center
Kourosh Shahraki, Mehdi Tavakoli, Keivan Khosravifard, Maryam Aletaha, Hossein Salour
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 3 (2023), 3 October 2023 , Page 121-128
https://doi.org/10.51329/mehdioptometry181
Background: Orbital decompression is frequently indicated to treat exophthalmos and compressive optic neuropathy, among other indications for thyroid eye disease (TED). This study aimed to evaluate the outcomes of orbital decompression and compare the results by urgency and type of surgery in patients with TED.
Methods: In this cross-sectional study, we recruited patients with TED who had undergone emergency or elective orbital decompression surgery at a tertiary eye care referral center in Tehran, Iran, between 2010 and 2020. Ophthalmic examination findings, demographic and clinical profiles, and types and outcomes of surgical interventions were reviewed and analyzed.
Results: Fifty-one orbits of 35 patients with a mean (standard deviation [SD]) age of 36.2 (12.0) years and male-to-female ratio of 23 (66%)/12 (34%) were included. The mean (SD) duration from the diagnosis to the surgery was 41.0 (39.0) months. The surgical method was fat decompression in 1 (2%) orbit; fat and inferior wall decompressions in 2 (4%) orbits; fat, inferior, and medial wall (two-wall) decompressions in 43 (84%) orbits; and fat, inferior, medial, and lateral wall (three-wall) decompressions in five (10%) orbits. Three-wall decompression surgery resulted in significantly lower exophthalmometry readings than those associated with two-wall surgery at all postoperative follow-ups (P < 0.05). Ten (20%) orbits required emergency decompression because of sight-threatening conditions and revealed comparable exophthalmometry readings with electively decompressed orbits at the 1-year visit (P > 0.05). Thirty-seven (73%) orbits required other surgeries within the 1-year follow-up. The mean (SD) exophthalmometry readings before and 1-year after surgery were 26.3 (4.0) and 18.3 (2.7) mm, respectively, with a significant decrease and significant 5.5 (3.3)-mm change from baseline in decompressed orbits (both P < 0.001). Diplopia was reported in 29% (n = 10) of patients less than 2 months postoperatively.
Conclusions: Emergency or elective orbital decompression significantly reduced exophthalmos in patients with TED within 1 year postoperatively. Three-wall orbital decompression produced the more immediate impact, while two-wall orbital decompression showed the higher effect at a later timepoint. The most common complication was diplopia, while other serious complications occurred infrequently. Further prospective comparative studies involving more participants and longer postoperative follow-up periods are required to verify these preliminary findings.
Association of metformin use with age-related macular degeneration risk
Michael R. Kozlowski
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 3 (2023), 3 October 2023 , Page 129-134
https://doi.org/10.51329/mehdioptometry182
Background: The association between metformin use and reduced age-related macular degeneration (AMD) risk has been explored. Studies have shown a positive association, no association, or ambiguous results. The aim of this narrative review is to compile these divergent findings, and thereby, better assess the potential of metformin use in reducing the AMD risk.
Methods: Studies were extracted in two ways. First, a standard Google Scholar™ search was performed using the keywords “metformin” AND “macular degeneration” without language or time restrictions. The full texts of relevant articles identified in this search were retrieved and assessed, and articles of peer-reviewed original studies and meta-analyses were included. Second, the reference lists of the included articles were used to identify additional articles that satisfied the search algorithm and included in this review.
Results: Of the 12 studies included in this review, eight showed a positive correlation between metformin use and a reduced AMD risk, while one showed no association. Of the eight positive studies, seven were retrospective. Apart from the design, the studies were also diverse. The number of participants in each study ranged from over 300 to 30 million person-years. The study populations included those with type 2 diabetes mellitus, those with AMD, and those without either. The study locations were the United States, Europe, and Asia. The ambiguous or negative results from four studies could largely be rationalized based on the confounding factor of study design.
Conclusions: Most studies examined in this review demonstrated a positive association between metformin use and a reduced AMD risk. Studies not reporting such an association did not definitively demonstrate its absence. Overall, the studies reviewed herein support further clinical investigation of metformin as a prophylactic and potential treatment modality for AMD. Further randomized clinical trials with reasonably longer follow-up periods are necessary to determine the generalizability of the findings of studies reporting positive results.
Headache associated with travoprost
Sajeev Cherian Jacob, Kalikivayi Venkateswara Kalyan, Lavanya Kalikivayi, Venkataramana Kalikivayi
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 3 (2023), 3 October 2023 , Page 135-140
https://doi.org/10.51329/mehdioptometry183
Background: Putative adverse effects of prostaglandin analogs in patients treated for glaucoma include periocular skin darkening, herpes simplex keratitis, cystoid macular edema, iritis, and headaches. Here, we report a case of migraine headache after a travoprost administration and discuss the role of prostaglandin analogs in migraine-like headaches.
Case Presentation: A 70-year-old man visited the hospital complaining of pain, redness, and sensitivity to light for 1 week associated with gradual loss of vision in the right eye after cataract surgery, which had been performed 2 years prior. After the examination, the patient was diagnosed with pseudophakic bullous keratopathy and advised to undergo optical penetrating keratoplasty of the right eye. On postoperative day 3, his intraocular pressure (IOP) was 30 mmHg at 10:00 AM in the right eye. A single dose of 0.004% travoprost was instilled in the right eye on the same day. His IOP decreased to 16 mmHg at 2:00 PM. The next day, he presented with migraine-like headache that had started within 1 h after the instillation the previous night. Unremarkable neurological examination and neuroimaging suggested that travoprost had caused the migraine. Although the headache gradually resolved, it reappeared after the administration of other prostaglandins. Trabeculectomy was performed on the right side. The IOP was controlled, and the headache was resolved.
Conclusions: This case indicates a potential causal relationship between topical prostaglandin analogs and migraine-like headaches, as evidenced by symptom resolution upon discontinuation. However, large-scale studies including control groups are required to prove a causal relationship between topical prostaglandin analog administrations and headache development.
Multimodal imaging in radiation retinopathy following orbital metastasis
Srinivasan Sanjay, Isha Acharya, Priya Srinivasan, Padmamalini Mahendradas
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 3 (2023), 3 October 2023 , Page 141-147
https://doi.org/10.51329/mehdioptometry184
Background: Radiation retinopathy is a major cause of vision loss in patients receiving radiotherapy to the head and orbit. Diabetic retinopathy is one of the differential diagnosis owing to similar clinical features, including microaneurysms, cotton-wool spots, hard exudates, and macular edema. The only significant pathological difference is that radiation retinopathy spares pericytes, unlike in diabetic retinopathy. Multimodal imaging helps diagnose and predict the prognosis of radiation retinopathy, which is presented in this case report.
Case Presentation: A 55-year-old woman diagnosed with stage-4 metastatic breast carcinoma presented with gradual diminution of vision in the left eye (OS) over 5 months. Vision in the right eye was lost because of orbital radiotherapy for orbital metastasis. The patient underwent multiple sessions of chemotherapy and radiotherapy. Examination of the left eye revealed a best-corrected distance visual acuity (BCDVA) of 20/30. Fundus examination of the OS revealed multiple cotton-wool spots and retinal hemorrhages. Fundus fluorescein angiography (FFA) showed diffuse macular leakage with capillary nonperfusion. Multicolor imaging (MCI) with Spectralis™ revealed black dots in the blue and green reflectance images, corresponding to capillary dilatation on FFA. Darker dots were more evident in the infrared images. BCDVA improved to 20/20 in OS after tapering the dose of oral steroids for 2 months, with improvements in hemorrhages and cotton-wool spots. Focal laser photocoagulation was recommended for the treatment of persistent macular edema. The patient declined further treatment, was lost to follow-up, and passed away 6 months later.
Conclusions: This case highlights the importance of multimodal imaging for the identification and classification of radiation retinopathy. MCI using SpectralisTM has been described for the first time in radiation retinopathy and can be used to complement existing imaging modalities. Future studies involving more patients and a longer follow-up duration may provide better results for the applicability of these imaging modalities in the clinical setting.
Summer 2023
Vol. 4 No. 2 (2023)
Effects of artificial tears on keratocyte cell density after femtosecond laser in situ keratomileusis: a prospective, comparative, interventional, contralateral eye study
Noor Shazana Md Rejab , Muhammad Emy Iekmal Bin Yusof , Mohd Radzi Hilmi, Khairidzan Mohd Kamal
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 2 (2023), 22 June 2023 , Page 50-56
https://doi.org/10.51329/mehdioptometry173
Background: Flap creation during laser refractive surgery restructures the anterior cornea, particularly the stroma, reducing the keratocyte cell density (KCD). This reduced density makes it challenging to completely regenerate to the presurgical phase. The aim of the present study was to investigate the effects of two types of artificial tear (AT) interventions on KCD up to 3 months after femtosecond laser-assisted in situ keratomileusis (FS-LASIK) surgery.
Methods: This prospective, double-blind, comparative, interventional, contralateral eye study recruited patients with myopia scheduled for FS-LASIK. Inclusion criteria were healthy individuals aged 19 – 25 years with moderate or high myopia, a maximum cylindrical error of – 1.25 diopters, and a maximum pupil size of 6.5 mm who had undergone FS-LASIK and completed 3 months of follow-up. Complete optometric and ophthalmologic examinations were performed. Bilateral simultaneous FS-LASIK surgery was performed using the same femtosecond laser platform as in the standard procedure. The Research Randomizer was used to determine the eye to be treated with Systane® Hydration (Alcon Laboratories, Inc., Fort Worth, TX, USA) or Systane® ULTRA (Alcon Laboratories, Inc., Fort Worth, TX, USA) AT. KCD was examined using real-time images obtained from in vivo confocal microscopy (Heidelberg Retina Tomograph 3 with the Rostock Cornea Module, HRT III RCM); Heidelberg Engineering GmbH, Heidelberg, Germany) at baseline and 1- and 3-month postoperative visits.
Results: We included 60 eyes of 30 participants with a mean (standard deviation) age of 21.34 (1.85) years and a male-to-female ratio of 1:1 who completed 3-month post-FS-LASIK surgery follow-up. KCD did not differ significantly between the two groups at any visit (all P > 0.05); nevertheless, mean KCD was initially reduced up to 1 month postoperatively and then revealed a slight increase up to 3 months postoperatively in Systane® Hydration-treated eyes and continued to reduce in Systane® ULTRA-treated eyes. Intragroup comparisons revealed that the eyes treated with ATs experienced a significant reduction in KCD between the preoperative and 1-month postoperative visits and between the preoperative and 3-month postoperative visits (all P < 0.05). Treatment-related complications were not observed.
Conclusions: Overall, KCD reduced up to 3 months post-FS-LASIK surgery. Both AT types exerted a comparable effect on postoperative KCD up to 3 months. Future studies with a more frequent administration of ATs, longer follow-up periods, and a control group are required before preliminary outcomes of the present study can be generalized.
Topographic correspondence of peripheral retinal lesions between the fellow eyes of patients with rhegmatogenous retinal detachment and retinal break
Kaveh Fadakar, Elaheh Havashki, Zohre Ebrahimi, Hanieh Niktinat, Mohammad Zarei , Raziyeh Mahmoudzadeh, Ehsan Najibzadeh, Nazanin Ebrahimiadib
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 2 (2023), 22 June 2023 , Page 57-62
https://doi.org/10.51329/mehdioptometry174
Background: In rhegmatogenous retinal detachment (RRD), the risk of fellow eye involvement varies from 5% to 34% according to the follow-up duration and criteria used for patient selection. The aim of the present study was to investigate the frequency, characteristics, and predisposing factors for symmetric lesions in the fellow eyes of patients with RRD or retinal breaks.
Methods: This case series included consecutive patients with recent-onset RRDs or retinal breaks. Eyes with traumatic breaks or RRD, grade C proliferative vitreoretinopathy, extensive (more than 6 h) lattice degeneration, a history of RRD surgery or pars plana vitrectomy in the fellow eye, or concomitant retinal pathologies, such as diabetic retinopathy, macular neovascularization, uveitis, or glaucoma, were excluded. Demographic data, best-corrected distance visual acuity, refraction, break characteristics, and expansion of the retinal detachment were recorded.
Results: Of the 68 participants, with a mean (standard deviation) age of 48 (12.1) years, 54 (79.4%) were men, and 14 (20.6%) were women. Of the 68 primary eyes, 60 (88.2%) had RRDs, and eight (11.8%) had retinal breaks. Horseshoe tears were the main lesion in 41 (68.3 %) primary eyes with RRD. Symmetric lesions were observed in 37 (54.4%) fellow eyes, including retinal breaks in 16 (43.2%) and lattice degeneration without breaks in 21 (56.8%) eyes. Lattice degeneration and multiple breaks were observed in 15 of 28 (53.6%) primary eyes with a lattice, whereas only seven of 40 (17.5%) lattice-free primary eyes had multiple breaks (P = 0.002). A multiple logistic regression model revealed that the presence of lattice degeneration in the primary eye (odds ratio, 26.91; 95% confidence interval, 4.18 – 173.20; P < 0.001) was the only factor predicting symmetricity in the fellow eye.
Conclusions: More than half of the patients with RRD or retinal breaks in the primary eye harbored symmetrical retinal lesions in their fellow eyes. This emphasizes the importance of regular examination of the fellow eyes with a greater focus on symmetric positions in the fellow eye. The presence of a lattice in the primary eye was the only predictor of symmetry in the contralateral eye. Further longitudinal studies with larger populations are required to determine the significance of these symmetric lesions in the fellow eyes of patients with RRD and the value of prophylactic treatment.
Systemic complications of intravitreal bevacizumab: a case report and literature review
Ana Laura Gramajo, Maria Emilia Aucar, Maria Victoria Laborie , Patricio Gerardo Schlottman, Jose Domingo Luna
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 2 (2023), 22 June 2023 , Page 63-75
https://doi.org/10.51329/mehdioptometry175
Background: Systemic complications of intravitreal bevacizumab (IVB) injections have been previously reported. We aimed to summarize the systemic complications reported in online primary studies. Moreover, we describe a patient experiencing simultaneous renal and cutaneous drug-induced adverse effects, with exacerbation of chronic renal insufficiency and granulomatous skin lesions, after receiving several IVB injections to manage bilateral ischemic branch retinal vein occlusion (BRVO).
Case Presentation: A 69-year-old Hispanic diabetic man with chronic renal insufficiency due to polyclonal gammopathy received several IVB injections to treat bilateral ischemic BRVO. One week after the sixth injection, the patient developed acute-on-chronic renal failure and multiple rounded maculopapular, erythematous, and ulcerated skin lesions. Renal and skin biopsy specimens revealed granulomatous drug-induced responses in both organs, and granulomatous diseases of infectious and oncological sources were ruled out. We performed an electronic search of the PubMed/MEDLINE database with no language or time restrictions using the keywords “intravitreal bevacizumab” or “intravitreal Avastin” combined with “systemic side effects,” “systemic complications,” or “systemic adverse,” or “systemic adverse event.” The search yielded 147 articles published over almost two decades. After screening and assessment, we selected and summarized 40 primary studies that mentioned IVB-related systemic complications.
Conclusions: IVB-induced systemic complications, such as arteriothrombotic events, venous thrombotic events, and hypertension, are rare but potentially serious. Care should be taken when administering multiple doses of intravitreal IVB to patients with pre-existing kidney dysfunction. Bevacizumab-related toxicity must be considered in cases of sudden deterioration of renal function and / or unexpected granulomatous skin lesions in oncologic or chronically polymedicated patients.
A practical clinical approach to traumatic choroidal rupture
Omer Ozer
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 2 (2023), 22 June 2023 , Page 76-82
https://doi.org/10.51329/mehdioptometry176
Background: Traumatic choroidal rupture is a posterior segment manifestation of trauma and is more common in closed-globe injuries. It is defined as a tear of the choroid and Bruch’s membrane following blunt trauma. This narrative review summarizes the current literature and provides a practical clinical approach to the diagnosis and management of traumatic choroidal rupture and its complications.
Methods: In this narrative review, we searched the PubMed/MEDLINE database using the search term choroidal rupture to provide a practical and updated approach to traumatic choroidal rupture, focusing on its definition, etiology, diagnosis, imaging, management of complications, and prognosis as mentioned in the literature over the last two decades.
Results: Traumatic choroidal rupture occurs due to increased tensile stress on the eye wall and is three-fold more common in closed-globe injuries than in open injuries. Subretinal or sub-retinal pigment epithelial hemorrhage and macular edema are early signs. Macular involvement is associated with poor visual prognosis. Damage to Bruch’s membrane increases the risk of subretinal choroidal neovascular membrane (CNVM). Traumatic epiretinal membrane is another complication. Imaging modalities such as spectral-domain optical coherence tomography, indocyanine green angiography, conventional fundus fluorescein angiography, and optical coherence tomography angiography (OCT-A) can be used in diagnosis or monitoring for complications. OCT-A offers unique opportunities for the diagnosis, treatment, and follow-up of both the initial presentation and possible complications. Frequent follow-up has been suggested in the first year after trauma. Intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection is effective and less invasive in managing CNVM. The visual outcome depends on the location of the rupture, baseline visual acuity, and presence of optic atrophy or macular holes. Risk factors for developing CNVM include rupture involving the macula, longer rupture length or rupture closer to the foveal center, and older age.
Conclusions: Choroidal rupture is a posterior segment entity that usually occurs after trauma, compromises choroidal vessels and Bruch’s membrane, and can lead to CNVM. The use of novel noninvasive imaging modalities and efficient anti-VEGF therapy to manage this entity or its subsequent complications produces better visual outcomes. Early diagnosis and frequent follow-up of these patients allow treatment of possible complications, thereby improving the visual prognosis.
An update on RPE cell senescence as a key contributor to age-related macular degeneration: support from current and experimental treatments
Michael R Kozlowski
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 2 (2023), 22 June 2023 , Page 83-94
https://doi.org/10.51329/mehdioptometry177
Background: Age-related macular degeneration (AMD) is a major cause of vision loss. Its prevalence has increased over the past decade. This increase is partly due to the scarcity of preventive and therapeutic interventions for this disorder, except when it is in its advanced neovascular form. Discovery of effective treatments for AMD is complicated by the multifactorial pathology of the disorder. Thus, it is difficult to determine which potential disease mechanism to target in order to achieve the greatest clinical benefit.
Hypothesis: Over a decade ago, it was hypothesized that many of the pathologies observed in AMD stem from retinal pigment epithelial (RPE) cell senescence. This provided a potentially key mechanistic target. Supporting this hypothesis, many of the agents that were in development or clinical use for AMD at that time influenced RPE cell senescence, although they were not utilized for this specific effect. The present article re-evaluates this hypothesis by exploring the logical prediction that if RPE cell senescence is a key contributor to AMD, then inhibition of RPE cell senescence is important in the treatment of AMD. If this hypothesis holds true, the inhibition or reversal of RPE cell senescence or its effects should be a common characteristic of new treatments for AMD.
Conclusions: Over the past decade, many agents have been investigated for the treatment of AMD. Although a few were designed to address cell senescence, the majority targeted other potential pathological mechanisms. In support of our original hypothesis, we now present evidence that many of the newer agents investigated for the treatment of AMD, even those that were not meant to reduce cell senescence or its effects, have this function as part of their activity profiles. Further experimental studies or clinical trials exploring the safety and efficacy of inhibiting RPE cell senescence or reversing its effects are needed to pave the way for improved AMD treatment.
Unilateral macular branch retinal vein occlusion in a healthy Indian woman following coronavirus disease vaccination: a case report and comprehensive literature review
Srinivasan Sanjay, Naresh Kumar Yadav, Ankush Kawali, Aditi Gupta, Padmamalini Mahendradas
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 2 (2023), 22 June 2023 , Page 95-101
https://doi.org/10.51329/mehdioptometry178
Background: The coronavirus disease (COVID-19) vaccines exert ocular adverse effects, including episcleritis, scleritis, anterior and recurrent uveitis, acute macular neuroretinopathy, paracentral acute middle maculopathy, ophthalmic vein thrombosis, Graves’ disease, arteritic anterior ischemic optic neuropathy, non-arteritic anterior ischemic optic neuropathy, central serous chorioretinopathy, Vogt-Koyanagi-Harada disease, multifocal choroiditis, cranial nerve palsies such as facial or abducens nerve palsy, acute zonal occult outer retinopathy, acute zoster ophthalmicus following re-activation of the varicella-zoster virus, acute retinal necrosis, and multiple evanescent white dot syndrome. In this case report, we explored the possibility of macular branch retinal vein occlusion and its association with COVID-19 vaccination.
Case Presentation: A 44-year-old healthy woman presented with unilateral nonprogressive blurring of vision in the right eye (OD). Her best-corrected distance visual acuity (BCDVA) in OD was 20 / 40. The anterior-segment evaluation was normal. Fundus evaluation of the OD revealed macular branch vein occlusion. She had a history of COVID-19 vaccination within 1 month. The interleukin-6 level was elevated six folds to 30.5 pg / mL. However, COVID-19 immunoglobulin G (IgG) antibodies were negative. Infective etiologies, such as tuberculosis and dengue, were ruled out. Spectral-domain optical coherence tomography (SD-OCT) of the OD showed hyperreflective dots in the posterior vitreous, inner retinal swelling, and cystoid changes in the macula. The maximum central macular thickness was 486 mm. A single dose of bevacizumab was administered at OD intravitreally. At the final follow-up 2.5 months later, her BCDVA had improved to 20 / 20 OD. Fundus evaluation revealed fewer retinal hemorrhages and cotton wool spots. SD-OCT of the OD showed a normal foveal contour and absence of cystoid spaces. Her maximum central macular thickness was 236 mm.
Conclusions: A temporal effect of vein occlusion secondary to COVISHIELD™ vaccination may occur in the absence of systemic risk factors. The interleukin-6 level was elevated, and the remaining blood test results were within normal limits. Since this is a case report, it is limited by the absence of strong evidence to prove this causal relationship between macular branch retinal vein occlusion and the specific brand of COVID-19 vaccination.
Spring 2023
Vol. 4 No. 1 (2023)
A prospective contralateral eye comparison of the tolerability of two artificial tears with different physical properties in patients with dry eye disease
Fatin Amalina Che Arif, Mohd Radzi Hilmi, Khairidzan Mohd Kamal
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 1 (2023), 4 April 2023 , Page 1-6
https://doi.org/10.51329/mehdioptometry167
Background: Artificial tears (ATs) are widely used in ophthalmic practice with various formulations, mainly as a treatment for dry eye, owing to their rapid ability to alleviate the signs and symptoms of this condition. We aimed to investigate drop comfort and subjective ocular symptoms after instillation of the following ATs with different physical properties: Optive® non-preservative (OUD) and Systane® Hydration non-preservative (SHUD).
Methods: This was a prospective, double-blind, randomized, contralateral eye comparison study. A rheometer and a digital pH meter were used to evaluate the viscosity and pH of both ATs prior to instillation. We recruited 36 patients with dry eye disease. Single standardized AT volumes were set using a micropipette for all patients. Ocular discomfort was assessed using the Ora Calibra™ Ocular Discomfort and 4-Symptom Questionnaire (OOD4SQ; 0 – 5 scale) before and 60 min after instillation. Drop comfort was assessed using the Ora Calibra™ Drop Comfort Scale (0 – 10 scale) immediately after AT instillation. The difference in the drop comfort score (DCS) between the two ATs and ocular discomfort scores using OOD4SQ before and 60 min after instillation of each AT were recorded and compared.
Results: The viscosities and pH of SHUD and OUD were 32.73 centipoise (cP) and 7.74 and 14.42 cP and 7.19, respectively. The mean (standard deviation) DCS was higher in the SHUD group than in the OUD group (1.83 [1.21] versus 1.67 [1.12]); however, the difference was not statistically significant (P > 0.05). There was a significant reduction in all parameters of OOD4SQ including overall discomfort, burning, dryness, grittiness, and stinging 60 min after OUD instillation (all P < 0.05), while a significant difference was only noted in dryness (P < 0.05) in the SHUD group.
Conclusions: OUD, which has a lower viscosity and pH compared to SHUD, provides less subjective sensation and better ocular comfort 60 min after instillation. Further randomized clinical trials including patients with dry eye disease of different severities, larger sample sizes, and longer follow-up periods are required to verify our findings.
Corneal topography and higher-order aberrations in patients with type 2 diabetes mellitus
Amir Asharlous , Abbas Riazi , Alireza Jamali , Sattar Rajabi, Masoud Rahimi , Ali Akbarzadeh, Mehdi Khabazkhoob, Samira Janani, Taghi Naghdi
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 1 (2023), 4 April 2023 , Page 7-16
https://doi.org/10.51329/mehdioptometry168
Background: Changes in blood sugar levels cause alterations in the anterior segment and retina of the eye. This study was aimed at evaluating corneal topography, aberrometry, and corneal asphericity in patients with treatment-naive type 2 diabetes mellitus (T2DM).
Methods: Participants with treatment-naive T2DM were enrolled in this cross-sectional study. The inclusion criteria were glycated hemoglobin A1c (Hb A1c) greater than or equal to 7.5% and absence of other ocular or systemic diseases. Patients who refused to participate or had a history of topical or systemic steroid use, hyperlipidemia, hypertension, anemia, prior ocular disorder or surgery, diabetic retinopathy, glaucoma, cataract, active ocular inflammatory or infectious disease, or contact lens use were excluded. All participants underwent a comprehensive ophthalmic examination. The Pentacam HR Scheimpflug tomography system (Pentacam High Resolution; Oculus, Wetzlar, Germany) was used to measure the anterior-segment parameters.
Results: Sixty eyes of 30 patients with a male-to-female ratio of 1:1 were included; the mean (standard deviation [SD]) age and Hb A1c were 51.63 (6.73) years and 8.82% (1.31%), respectively. The mean (SD) values of central corneal thickness, root mean square (RMS) of total aberration, RMS of lower-order aberrations, RMS of higher-order aberrations, spherical aberration, 0° coma, 90° coma, flat anterior keratometry (K), steep anterior K, mean anterior K, anterior topographic astigmatism, flat posterior K, steep posterior K, mean posterior K, posterior topographic astigmatism, anterior corneal asphericity, and posterior corneal asphericity were 540.22 (24.47) µm, 1.72 (0.73) µm, 1.63 (0.73) µm, 0.51 (0.17) µm, + 0.31 (0.09) µm, – 0.06 (0.15) diopters (D), 0.003 (0.21) D, 43.87 (1.49) D, 44.69 (1.50) D, 44.28 (1.44) D, + 0.82 (0.83) D, – 6.25 (0.27) D, – 6.55 (0.31) D, – 6.40 (0.28) D, – 0.30 (0.15) D, – 0.32 (0.12) Q-value, and – 0.47 (0.17) Q-value, respectively.
Conclusions: We presented the mean values of Pentacam parameters for aberrometry, keratometry, and corneal asphericity in patients with treatment-naive T2DM. These values could serve as a baseline for prospective monitoring of the ocular health status of this cohort and for comparison with future cohorts of patients with well-controlled T2DM. Further studies are required to assess the presence and applicability of ocular changes following intensive blood glucose control in T2DM and further understand the related pathophysiology.
Binocular vision parameters and body mass index
Nivedhitha Elangovan, Deepa Bangalore Muniyappa Shanmugham
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 1 (2023), 4 April 2023 , Page 17-24
https://doi.org/10.51329/mehdioptometry169
Background: Abnormal body mass Index (BMI) can adversely affect binocular vision. We aimed to assess the presence of possible differences in binocular vision parameters among the four BMI categories.
Methods: In this comparative cross-sectional study, we enrolled young adults and categorized them into underweight, normal weight, overweight, and obese groups based on their BMI. A complete orthoptic evaluation was performed to assess the mean values of binocular vision skills.
Results: We recruited 120 participants with a mean (standard deviation) age of 21.30 (1.80) years with best-corrected distance and near visual acuities of 6/6 and N6, respectively. The frequency of exophoria > 4 PD was high in the obese group. The frequency of binocular vision dysfunction was higher in the obese and underweight groups, with vergence dysfunction being the most common. The mean values for near negative fusional vergence (NFV), distance positive fusional vergence (PFV), negative relative accommodation, positive relative accommodation, monocular accommodation facility (AF), and monocular estimation method were comparable among the groups (all P > 0.05). The obese group had significantly receded near point of convergence, and reduced accommodative convergence to accommodation ratio and binocular AF than the normal, overweight, and underweight groups (all P < 0.05). The distance and near vergence facilities were significantly lower in the obese group than in the overweight and normal groups, and the distance vergence facility was significantly lower than in the underweight group (all P < 0.05). The mean values of distance NFV and near PFV in the obese group were significantly lower compared to the normal and overweight groups, and the mean values of distance NFV were significantly lower compared to the underweight group (all P < 0.05). The mean values of near PFV were significantly lower in the underweight group than in the overweight group (both P < 0.05). Both the underweight and obese groups had a significantly lower amplitude of accommodation compared to the normal group (both P < 0.05).
Conclusions: The frequency of binocular vision dysfunction was higher in the obese and underweight groups. Most convergence and some accommodation parameters were adversely affected in individuals with obesity. Being underweight adversely affects certain binocular vision skills. Further studies are required to determine the relevance of BMI as a predictor of binocular vision abnormalities.
Pediatric cycloplegic refraction
Mahmoud Eltagoury, Ehab Ghoneim
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 1 (2023), 4 April 2023 , Page 25-33
https://doi.org/10.51329/mehdioptometry170
Background: Cycloplegic refraction is an essential part of the pediatric ophthalmic assessment and is the cornerstone of strabismus evaluation. This narrative review aimed to ascertain the current scope of practice for cycloplegic refraction in the pediatric population.
Methods: An extensive literature review was conducted using ScienceDirect, PubMed/MEDLINE, Scopus, and Google Scholar databases using the following search terms: cyclopentolate, tropicamide, pediatric cycloplegia, atropine, homatropine, manual retinoscope, handheld autorefractometer, spherical errors, and no spherical errors of refraction in articles published from January 2000 to December 2022. Relevant retrieved references and practical points concerning pediatric cycloplegic refraction were summarized.
Results: Atropine has the most potent cycloplegic effect and is best used in cases of severe accommodative esotropia. Because of the unfavorable side effects and risks associated with atropine, cyclopentolate has been found to provide quite effective cycloplegia, even for moderate to severe hyperopia, and has become the standard agent for traditional pediatric cycloplegic exams. Tropicamide has also been shown to provide adequate cycloplegia while being less toxic and causing fewer side effects. Tropicamide has the fewest side effects and toxicity of all agents, while atropine has the most. Cyclopentolate is an exceptionally safe cycloplegic agent. To detect spherical and non-spherical refractive errors, refraction can be performed using a handheld autorefractometer or a manual retinoscope, as well as under general anesthesia in some cases. The optimal time to wear eyeglasses to maintain binocular vision and avoid amblyopia is also considered.
Conclusions: Accommodative power in children is at its maximum, and this interferes with reliable – assessment of refraction. Therefore, the use of cycloplegic refraction is mandatory during childhood to obtain actual refraction, which is considered the cornerstone for eyeglass prescription. Knowledge of the various cycloplegic agents used in childhood refraction is important for ophthalmologists and optometrists to obtain safe and effective cycloplegia. High refractive errors, as well as the presence of anisometropia or squint, necessitate the use of eyeglasses as early as childhood to maintain binocularity and depth perception.
Acute zonal occult outer retinopathy misdiagnosed as giant cell arteritis: a challenging case
Nickolas K Garson, Shivani Shah, Nazanin Ebrahimiadib, Siva SR Iyer, Ramak Roohipourmoallai
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 1 (2023), 4 April 2023 , Page 34-40
https://doi.org/10.51329/mehdioptometry171
Background: Acute zonal occult outer retinopathy (AZOOR) is a rare autoimmune retinopathy that is challenging to diagnose and treat. It usually presents with subtle fundus changes and severe visual symptoms. Herein, we report a challenging case of AZOOR, emphasizing that multimodal imaging could be valuable in diagnosis and monitoring of treatment response.
Case Presentation: A 53-year-old woman presented to the emergency department with a one-week history of subacute, severe, painless vision loss without photopsia in her right eye. Her best-corrected distance visual acuity was 20/800 in the right eye and 20/20 in the left eye. Slit-lamp examination findings were unremarkable, and intraocular pressure was normal in both eyes. Initially, fundus examination findings appeared normal; however, serum levels of inflammatory markers were elevated. Brain and orbital magnetic resonance imaging results were unremarkable. A relative afferent pupillary defect was present in subsequent follow-up examinations at the hospital. The patient initially received a diagnosis of posterior ischemic optic neuropathy secondary to occult giant cell arteritis, underwent steroid treatment, and was evaluated by rheumatology and neurology consultants. Both consultants concurred with the presumed diagnosis. Subsequent multimodal imaging in the ophthalmology clinic revealed a trizonal pattern of fundus autofluorescence. Corresponding to these areas, we noted a loss of the ellipsoid zone on optical coherence tomography, depression on multifocal electroretinogram, and scotoma on visual field testing. Accordingly, the diagnosis of AZOOR was made. The patient was referred back to the rheumatologist for initiation of steroid-sparing treatment, and methotrexate was administered. Five months after the initial presentation, the patient showed significant visual field improvement in both eyes.
Conclusions: Eye care practitioners should consider AZOOR in the differential diagnosis of patients with subacute painless severe unilateral vision loss and unremarkable findings on fundus examination. Multimodal imaging could be valuable in diagnosis and monitoring of treatment response, as observed in the current case. Further studies with larger sample sizes are needed to confirm the value of multimodal imaging and the available management options for AZOOR.
Paracentral acute middle maculopathy progressing to central retinal artery occlusion following coronavirus disease vaccination: a multimodal imaging report
Srinivasan Sanjay, Shama Sharief , Santosh Gopikrishna Gadde, Balughatta Poornachandra
Medical hypothesis, discovery & innovation in optometry, Vol. 4 No. 1 (2023), 4 April 2023 , Page 41-49
https://doi.org/10.51329/mehdioptometry172
Background: Coronavirus disease (COVID-19) vaccines can cause adverse ocular effects, including vascular insults, acute macular neuroretinopathy, paracentral acute middle maculopathy (PAMM), ophthalmic vein thrombosis, Graves’ disease, arteritic anterior ischemic optic neuropathy (A-AION), and nonarteritic AION. Here, we report a case of unilateral PAMM progressing to central retinal artery occlusion (CRAO) after COVID-19 vaccination, identified using multimodal imaging.
Case Presentation: A 24-year-old healthy man presented with unilateral progressive blurring of vision in the right eye. He had a recent history of fever without rashes 2 weeks after coronavirus disease vaccination. He was diagnosed with PAMM in the right eye at a local hospital and treated with a tapering dose of oral steroids. At presentation, he showed progressive blurring of vision in the right eye and the best-corrected distance visual acuity (BCDVA) was 20/60. The anterior segment was normal. Fundus examination revealed a pale optic disc with arteriolar attenuation and barrage laser scarring at the inferotemporal periphery. CRAO was diagnosed based on the right eye findings. The patient underwent multimodal imaging, including wide-field fundus photography using Optos® (Optos Carfornia®, Optos Inc., Dunfermline, United Kingdom), multicolor imaging with Spectralis™ (Heidelberg Retinal Angiograph; Heidelberg Engineering, Inc., Dossenheim, Germany), fundus fluorescence angiography (Heidelberg Retinal Angiograph; Heidelberg Engineering, Inc., Dossenheim, Germany), and optical coherence tomography angiography (ANGIOVUE, OPTOVUE, Inc., Fremont, CA, USA) using the split-spectrum amplitude-decorrelation angiography algorithm. The condition progressed from PAMM to CRAO during the oral steroid treatment course. At the 2-month follow-up, the right eye BCDVA had improved to 20/50, with fundus findings remaining the same as at the previous visit.
Conclusions: This was the first report of a young patient with PAMM presenting with focal vascular occlusion that evolved to global occlusion in the form of CRAO in the absence of systemic vascular risk factors and with a normal coagulation profile. This case suggests that arterial occlusion may exert a temporary effect secondary to COVISHIELD™ vaccination. Randomized controlled trials and case – control studies on the role of vaccination in precipitating thromboembolic events in healthy individuals would provide insight into the causation.
Winter 2022
Vol. 3 No. 4 (2022)
Seven-year experience in a low vision rehabilitation clinic at a tertiary referral center
Abbas Riazi, Reza Gharebaghi, Fatemeh Heidary
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 4 (2022), 14 January 2023 , Page 128-135
https://doi.org/10.51329/mehdioptometry161
Background: Low vision is a major public health concern worldwide. This study was aimed at describing the characteristics of patients who had visited a low-vision rehabilitation clinic.
Methods: In this retrospective study, we reviewed the medical records of patients with low vision attending a low-vision rehabilitation clinic at a tertiary referral center over 7 years. Inclusion criteria were a diagnosis of vision impairment and availability of complete records. We extracted the following data from each record: age, sex, education level, employment status, chief complaints concerning vision, associated ocular diseases, uncorrected distance and near visual acuities, best-corrected distance and near visual acuities, statuses of previous and current prescribed optical devices, and cooperation status of patients during the optometric examination.
Results: We enrolled a total of 567 patients, including 338 (59.6%) men and 229 (40.4%) women, with a mean (standard deviation) age of 40.46 (28.34) years. Most (98.4%) participants were cooperative, with a high rate of unemployment (90.5%) and low education level. Half (49.2%) of the patients had moderate visual impairment. Retinal pathologies, mainly congenital (28.4%), and age-related macular degeneration (ARMD; 26.5%) were common causes of low vision. Difficulty in reading was the most frequent complaint (22.9%), and a combination of difficulties in reading, writing, and facial recognition was recorded in 54.7% of the patients. Other functional complaints were reported by at least 5% of the patients. Our multivariate logistic regression analysis revealed that the likelihood of difficulties in performing in-house activities, reading, facial recognition and social interaction, and driving increased per 10-year increment in age, with odds ratios of 1.39, 1.31, 1.24, and 1.22, respectively (all P < 0.05). The likelihood of reporting three complaints (reading, writing, and facial recognition together) increased per 0.1-logarithm of the minimum angle of resolution increment in the best-corrected distance visual acuity of the better eye, with an odds ratio of 2.05 (P < 0.05). In addition, men were more likely to experience difficulties in driving and reading, while women were more likely to experience difficulties in facial recognition and social interaction or in-house activities (all P < 0.05). Optical devices for distance or near vision were prescribed to most patients.
Conclusions: Most patients were men and unemployed. The most common category of low vision was moderate impairment. Retinal conditions, mainly congenital ones and ARMD, were the most frequent causes. A combination of difficulties in reading, writing, and facial recognition was the most common complaint. Optometrists should address these findings during rehabilitation therapy to treat patients with low vision.
Myopia progression in children before and after the coronavirus disease lockdown
Prema K Chande, Neepa Thacker Dave, Mumtaz Qazi, Priyanka Bapat Vora
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 4 (2022), 14 January 2023 , Page 136-141
https://doi.org/10.51329/mehdioptometry162
Background: The worldwide spread of the coronavirus disease (COVID-19) pandemic in 2020, followed by lockdowns, forced children to be in home confinement with increased screen time, leading to rapid progression of myopia and an increase in the prevalence of myopia. This study was aimed at determining if myopia progression seen in evidence-based practice resulted from the COVID-19 lockdown or delayed follow-ups.
Methods: A retrospective review of case sheets of patients visiting the pediatric department of a tertiary care eye hospital in Mumbai, India, was conducted from 2017 onwards. We enrolled all children with myopia who had attended at least one follow-up visit before the COVID-19 lockdown and at least one follow-up visit post-lockdown. The spherical equivalent (SEQ) of refractive error values at baseline and pre- and post-COVID-19 lockdown follow-ups (hereinafter referred to as the “first” and “second” follow-ups, respectively) were recorded. The duration between baseline and the first follow-up visit and between the first and second follow-up visits were noted.
Results: We enrolled 112 eyes of 56 children, including 35 (62.5%) boys and 21 (37.5%) girls, with a mean (standard deviation [SD]) age of 9.54 (2.82) years. The mean (SD) SEQ values at baseline and first and second follow-ups were – 4.74 (3.83), – 5.46 (3.81), and – 6.42 (3.66) D, respectively. The mean change in SEQ, mean SEQ myopia progression, and rate of myopia progression per month differed significantly between the baseline and the first follow-up visit versus between the first and second follow-ups (all P < 0.05). However, the change in myopia degree did not differ significantly between these two periods in eyes with low, moderate, or high myopia (all P > 0.05). The mean (SD) duration between the baseline and the first follow-up visit was 14.57 (5.68) months, while that between the first and second follow-ups was 27.96 (9.18) months, showing a significant difference (P < 0.05).
Conclusions: Our findings suggest that a longer gap between follow-up visits and myopia progression per month should be factored into the management of myopia. Considering that young children are more vulnerable, preventive measures and school reforms should be urgently implemented in India. Further retrospective multicenter studies with a larger sample size of eyes, including various refractive errors over a longer period, are required to verify these findings.
Impact of vision correction on the visual impairment status and quality of life score in patients with type II diabetes mellitus
Noor Suriani Mohamad, Chiranjib Majumder, Rokiah Omar
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 4 (2022), 14 January 2023 , Page 142-151
https://doi.org/10.51329/mehdioptometry163
Background: Visual impairment (VI) in patients with diabetes mellitus (DM) worsens as the disease progresses. Therefore, quality of life (QOL) may also be affected. Furthermore, in the absence of macular involvement, some patients may benefit from visual intervention. However, not many Malaysians with known DM had their eyes screened or used correctable spectacles. Consequently, the QOL and VI status of patients with DM in Malaysia remain unclear. This study was aimed at determining the impact of optometric intervention on the QOL and VI status of adults with type II DM.
Methods: This was a quasi-self-controlled, experimental study involving adults with known type II DM. We conducted face-to-face interviews using the low vision quality-of-life questionnaire (LVQOL). The habitual visual acuity (VA) of all participants was recorded. All participants underwent fundus photography to grade diabetic retinopathy (DR) in both eyes. Correctable VA was determined following subjective refraction when the best-corrected distance visual acuity (BCDVA) was 6 /9 and better. After a 3-week adaptation to the prescribed refractive error correction, LVQOL was repeated via a phone interview.
Results: A total of 47 participants with type II DM, including 16 (34%) men and 31 (66%) women, with a mean (standard deviation [SD]) age of 49.0 (7.9) years were recruited. The age range was 32 – 59 years, and the baseline mean (SD) habitual binocular VA was 0.52 (0.31) decimal. Only 15% (n = 7 patients) of the participants had their vision tested and wore glasses; however, some were uncomfortable with the current corrections. All patients had undercorrected or uncorrected refractive errors, namely, hyperopic astigmatism (47%), myopic astigmatism (38%), hyperopia (6%), myopia (4%), and antimetropia (4%). Among the 47 participants, 89% (n = 42) had uncorrected presbyopia. The mean (SD) LVQOL score at baseline was 91.9 (17.3), which improved significantly with visual intervention to 122.8 (3.2) (P < 0.05). Refractive error corrections significantly improved the VI status (P < 0.05), as all participants achieved a BCDVA of 6 / 9 and better.
Conclusions: Our findings indicate that optometric intervention is effective in improving the LVQOL and VI status of adults with type II DM. Further clinical optometric studies on type II DM with DR with a longer follow-up should be carried out to understand the clinical characteristics of this cohort and the impact of meticulous refractions on QOL in providing better services in the future.
Anterior-segment optical coherence tomography for tacrolimus therapy response monitoring of vernal keratoconjunctivitis
Mahmoud Eltagoury, Waleed Abou Samra, Ehab Ghoneim
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 4 (2022), 14 January 2023 , Page 152-159
https://doi.org/10.51329/mehdioptometry164
Background: Vernal keratoconjunctivitis (VKC), a chronic bilateral eye disease, is a severe form of allergic conjunctivitis. Anterior-segment optical coherence tomography (AS-OCT) is a rapid, noninvasive, in vivo visualization modality for the anterior segment structures that has been used in diagnosing and staging diseases and assessing the treatment efficacy. We used anterior-segment optical coherence tomography (AS-OCT) to monitor the efficacy of the tacrolimus eye ointment in managing VKC.
Methods: In this prospective follow-up study, we included patients with active symptomatic VKC. All patients were treated with the 0.03% tacrolimus ophthalmic ointment twice daily for 2 months and then once daily for 1 month. All patients underwent AS-OCT before and 3 months after treatment as an objective method to assess the treatment efficacy.
Results: We included 20 eyes of ten patients (nine men and one woman) with active symptomatic VKC. The mean age was 17.3 (range: 11 – 36) years, with nine patients having a palpebral type and one patient having a mixed type of VKC. Substantial flattening and reduction in the papilla size were observed in all patients at the post-treatment follow-up. AS-OCT measurements revealed significant reductions in the vertical, horizontal, and total diameters of the palpebral papillae and limbal conjunctival thickness after 3 months of treatment compared to baseline measurements (all P < 0.001). No serious adverse effects attributable to tacrolimus administration were observed in the study period.
Conclusions: AS-OCT is a suitable objective method for evaluating the treatment efficacy of the 0.03% tacrolimus eye ointment in patients with VKC. Future large-scale studies including a wide range of age groups with longer follow-up periods and AS-OCT monitoring at multiple post-treatment visits are required to confirm our preliminary results. Moreover, the diagnostic accuracy of AS-OCT in monitoring patients with active VKC should be tested in comparison with objective scoring by an experienced corneal fellowship.
Vortex keratopathy after photorefractive keratectomy in a patient on long-term clozapine treatment
Samir Shoughy, Hosam Elgemie, Waleed Nasif
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 4 (2022), 14 January 2023 , Page 160-164
https://doi.org/10.51329/mehdioptometry165
Background: Vortex keratopathy is a corneal entity characterized by corneal deposits at the level of the basal epithelium in the form of a whorl-like pattern in the interpalpebral portions of the cornea. Medications such as amiodarone, chloroquine, hydroxychloroquine, indomethacin, phenothiazines, ibuprofen, and naproxen bind to the cellular lipids of the basal epithelial layer of the cornea, producing a characteristic whorl pattern. Here, we report a case of bilateral central vortex keratopathy with slight vision impairment 3 weeks after uneventful photorefractive keratectomy (PRK) in a woman on long-term clozapine treatment.
Case Presentation: A 42-year-old woman presented to the outpatient clinic for refractive surgery for the correction of bilateral moderate myopia. Her best-corrected distance visual acuity was 20 / 20 in both eyes. She had been on antipsychotic clozapine tablets 400 mg / day for the past 6 years to manage a psychiatric disorder. On detailed preoperative slit-lamp examination, her corneas were clear, with perilimbal conjunctival pigmentations. Other ocular examination results were unremarkable. At the 3-week follow-up after an uneventful PRK, her uncorrected distance visual acuity was 20 / 25 in the right eye and 20 / 20 in the left eye, with complaints of slightly unclear vision in both eyes. Slit-lamp examination revealed bilateral corneal subepithelial deposits in a whorl-like pattern reminiscent of vortex keratopathy. The deposits were restricted to the epithelial and subepithelial regions and did not extend to the stroma without evident stromal haze. Dilated fundus examination results were normal bilaterally. Despite excellent refractive outcomes and visual acuity in both eyes, she was dissatisfied and complained of unclear vision. She was administered with lubricating eye drops and placed on regular follow-ups. At the 4-month follow-up, the vortex lines were cleared centrally, and she reported improvement in vision. Anterior-segment optical coherence tomography of the cornea revealed no epithelial deposits in the central part of the cornea and residual deposits in the temporal peripheral cornea, indicating clearing of the deposits from the central cornea and explaining the subjective improvement in vision. Her final best-corrected distance visual acuity was 20/20 in both eyes with an unremarkable ocular examination.
Conclusions: Our case indicates a potential causal relationship between long-term clozapine treatment and development of temporary, visually significant vortex keratopathy after uneventful PRK. Further large-scale studies are required to verify the causal relationship between the long-term clozapine administration and the development of vortex keratopathy following surface ablation photorefractive procedures.
Optical coherence tomography epithelial mapping for keratoconus screening
Sana Niazi, Farideh Doroodgar
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 4 (2022), 14 January 2023 , Page 165-166
https://doi.org/10.51329/mehdioptometry166
Letter to the Editor
Note: letters have no abstract.
Fall 2022
Vol. 3 No. 3 (2022)
Uveitis in spondyloarthropathies
Hashim Ali Khan , Qaim Ali Khan, Muhammad Aamir Shahzad
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 3 (2022), 30 December 2022 , Page 75-85
https://doi.org/10.51329/mehdioptometry155
Background: Uveitis is associated with several systemic disorders. It may be the initial presentation or manifestation of a systemic disease. It is the most common ocular complication and is sometimes the earliest manifestation of spondyloarthropathies. This study aimed to review the current literature on spondyloarthropathies and associated uveitis.
Methods: A narrative review was performed using various combinations of the keywords spondyloarthropathies, seronegative spondylarthritis-related uveitis, and human leukocyte antigen-associated uveitis using PubMed/MEDLINE and Google Scholar from January 1, 2000, to September 30, 2022. We describe the disease mechanisms, genetics, and classification of spondyloarthropathies, the clinical patterns of their related ocular diseases, and the current modalities for the management of their ocular or systemic manifestations.
Results: Seronegative spondyloarthropathies are a group of rheumatic disorders including ankylosing spondylitis, reactive arthritis, psoriatic arthritis, inflammatory bowel disease-related spondyloarthropathy, juvenile-onset spondyloarthritis, and undifferentiated spondyloarthritis. These are characterized by enthesitis in the absence of serum rheumatoid factor and have a strong association with human leukocyte antigen B27. The clinical courses and features of spondyloarthropathies are remarkably diverse. Ocular inflammation is common in spondyloarthropathies, often precedes the onset or diagnosis of systemic disease, and responds well to topical therapy. Timely diagnosis of systemic diseases may improve quality of life and help avoid ocular and skeletal complications. Recurrence of ocular inflammation is frequent; on occasion, it may be associated with etanercept administration.
Conclusions: Eye care professionals should be able to recognize spondyloarthropathies, manage ocular disease, and collaborate with related specialties for modification of systemic treatment if associated with ocular complications. Timely referral and early management could attenuate or prevent ocular or systemic morbidities associated with spondyloarthropathies.
Imaging techniques for ocular neoplasia
Amir Ahmadzadeh Amiri, Zahra Heidari, Reza Jafari, Ali Ahmadzadeh Amiri, Ahmad Ahmadzadeh Amiri
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 3 (2022), 30 December 2022 , Page 86-95
https://doi.org/10.51329/mehdioptometry156
Background: Novel ocular imaging modalities have greatly impacted the diagnosis and management of different types of ocular neoplasia. In this narrative review, we summarize the practical features of popular and novel imaging modalities for ocular tumors.
Methods: Four databases, including PubMed/MEDLINE, Web of Science, Scopus, and Google Scholar, were searched from January 1, 2000 to August 31, 2022. Articles reporting different imaging modalities for diagnosing or monitoring treatment responses of ocular tumors were extracted using various combinations of the following keywords: ocular neoplasia, positron emission tomography or PET, single-photon emission computed tomography or SPECT, optical coherence tomography or OCT, OCT angiography or OCTA, computed tomography or CT, ultrasonography or US, ultrasound biomicroscopy or UBM, and magnetic resonance imaging or MRI.
Results: Various ocular imaging modalities had different accuracies as adjunctive tools for detecting or managing ocular tumors. Anterior ultra-high-resolution optical coherence tomography (OCT) could be used to evaluate images with < 5-µm resolution. OCT angiography provided deeper insight into retinal vascular changes associated with the malignant transformation of choroidal melanoma. OCT in children altered the diagnosis of suspicious retinoblastoma in 3% of the cases and treatment plan in 11% of the cases. While positron-emission tomography (PET)/computed tomography (CT) allowed the detection of metastatic lesions of choroidal melanoma by full-body scanning, single-photon emission CT was more sensitive compared to PET in detecting choroidal melanoma. Ultrasound biomicroscopy, with an accuracy exceeding 92.5%, could detect retinal calcification in lesions measuring 2–3 mm. Magnetic resonance imaging (MRI) had better contrast compared to ultrasound biomicroscopy and higher sensitivity compared to CT in detecting post-laminar optic nerve invasion. However, MRI had a lower spatial resolution compared to OCT. Further development of imaging modalities and their application in drug development would improve the treatment of ocular tumors.
Conclusions: Although diagnosing ocular tumors depend on clinical characteristics, innovations in ocular imaging have enabled early diagnosis and timely, appropriate management of ocular neoplasia, which are conducive to favorable visual outcomes and increased life expectancy. Further systematic reviews and meta-analyses of primary studies focusing on a specific imaging modality in ocular neoplasia could precisely determine the diagnostic accuracy of each imaging modality to better guide eye practitioners with efficient diagnostic or therapeutic approaches for these sight- or life-threatening entities. Imaging modalities may play a major role in drug development in the future.
Refractive outcomes in infants treated for retinopathy of prematurity
Fatemeh Heidary, Reza Gharebaghi
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 3 (2022), 30 December 2022 , Page 96-105
https://doi.org/10.51329/mehdioptometry157
Background: Infants treated for retinopathy of prematurity (ROP) can develop visually significant refractive error. However, the degree of refractive error may differ between laser treatment and intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection. We reviewed studies that investigated refractive error outcomes of treatment in premature infants with ROP.
Methods: In this narrative review, a literature search was carried out in PubMed/MEDLINE from 01/01/2000 to 20/10/2022 without language restrictions, using the following keywords: “anti-VEGF,” “ROP” or “prematurity retinopathy,” and “laser.” We included comparative studies on refractive error outcomes of intravitreal anti-VEGF and laser treatments, a combination of both modalities simultaneously or sequentially, and two anti-VEGF agents.
Results: The initial search yielded 164 records. We reviewed the titles and abstracts of the retrieved papers and the reference list of published systematic reviews and meta-analyses, meta-analyses, or reviews on our topic. Thirty-three records fulfilled our inclusion criteria, which included refractive outcomes in 4350 eyes of 2359 participants treated for ROP. Based on the reported refractive outcomes, we divided the studies into four categories: 1) those that revealed a higher rate of refractive error in the laser-treated eyes than in the anti-VEGF-treated eyes; 2) those that revealed no significant difference in refractive outcomes between the two treatment modalities; 3) those that revealed a higher rate of refractive error in the anti-VEGF-treated eyes or compared refractive outcomes between two anti-VEGF agents; and 4) those that reported refractive outcomes in the eyes that received combined simultaneous or sequential treatment with laser after initial anti-VEGF treatment. We also summarized the refractive outcomes of all included primary studies in each category.
Conclusions: This study showed that the laser-treated eyes experienced more myopic shift. However, the refractive outcomes in premature infants of laser treatment, anti-VEGF treatment, and a combination of both modalities simultaneously or sequentially were often contradictory. This variability resulted from obvious differences in the sample size, different follow-up durations, or inhomogeneous study or treatment designs. Further well-designed prospective trials on refractive outcomes and the trend of changes in the refractive status over long-term follow-ups in the eyes treated with ROP are necessary to identify consensus results concerning real-world refractive outcomes of each treatment modality or simultaneous or sequential combination of both modalities, to suggest a safe and effective treatment option for eye care professionals.
Prevalence of refractive errors among school children in Wangsa Maju, Kuala Lumpur, Malaysia
Lili Asma Ismail, Sheiladevi Sukumaran
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 3 (2022), 30 December 2022 , Page 106-112
https://doi.org/10.51329/mehdioptometry158
Background: Uncorrected refractive error is the most common cause of vision impairment and the second leading cause of blindness worldwide. Its prevalence differs among and within countries. This study was aimed at exploring the pattern and prevalence of refractive error among school children in the Wangsa Maju Township, Kuala Lumpur, Malaysia.
Methods: A stratified, multistage, cluster random sampling in a geographically defined area was employed, and 245 school children, aged 8–12 years, from two primary schools in Wangsa Maju Township, Kuala Lumpur, were recruited. The cross-sectional study employed interviewing, measuring uncorrected distance visual acuity (UCDVA) using the Snellen chart, cycloplegic refraction under a streak retinoscope refined subjectively, and a detailed slit-lamp examination to assess the anterior and posterior segments. Myopia, hyperopia, and astigmatism were defined as spherical equivalent (SE) greater than or equal to – 0.50, SE greater than or equal to + 2.00, and cylindrical greater than or equal to 0.75 D, respectively. Reduced UCDVA was defined as an unaided visual acuity < 6/9.
Results: The mean (standard deviation) age of the participants was 10.42 (1.22) years. The overall prevalence of refractive error was 47.8%. Of 245 screened school children, including 42 (35.9%) boys and 75 (64.1%) girls, 117 had refractive error, with a prevalence of refractive error of 17.1% and 30.6% in boys and girls, respectively. Myopia was the most common type (30.2%), followed by astigmatism (16.3%) and hyperopia (1.2%). The prevalence of reduced UCDVA was 36.3% among the screened school children, attributable to refractive error with a significantly high positive correlation (r = +.721; P < 0.01). Among those with refractive errors, sex differences in the magnitude of refractive errors were not statistically significant in the three types of refractive errors (all P > 0.05).
Conclusions: The prevalence of refractive error among primary school children in Wangsa Maju Township, Kuala Lumpur, Malaysia was 47.8%; girls outnumbered boys, but the magnitude of refractive errors showed no sex differences. The prevalence of reduced UCDVA was 36.3%, attributable to refractive error. Irrespective of sex, myopia had the highest prevalence compared to other refractive errors, and its prevalence increased with age. Future population-based studies are required to address the limitations concerning environmental risk factors for refractive error and the impact of ethnic or familial backgrounds on their prevalence in a similar but larger population using the same protocol.
A 10-year review of the visual outcomes of early versus late pars plana vitrectomy in eyes with dropped lens fragment or nucleus during phacoemulsification
Fereydoun Farrahi, Ali Kasiri, Mostafa Feghhi, Malihe Darvishi Dastgerdi
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 3 (2022), 30 December 2022 , Page 113-118
https://doi.org/10.51329/mehdioptometry159
Background: Pars plana vitrectomy (PPV) is a routine surgical option for the removal of dropped lens fragment or nucleus in the vitreous cavity due to complicated cataract surgery; however, its optimal timing is controversial. Therefore, we aimed to determine the visual outcomes of early versus late PPV in eyes with dropped lens fragment or nucleus due to complicated phacoemulsification cataract surgery.
Methods: This descriptive-analytical retrospective study collected data of patients who underwent early (less than or equal to 1 week) versus late (> 1 week) PPV for the management of dropped lens fragment or nucleus resulting from complicated phacoemulsification cataract surgery over a 10-year period at Imam Khomeini Tertiary Referral Hospital, Ahvaz, Iran. Demographic characteristics, the interval between complicated phacoemulsification and PPV, pre- and postoperative intraocular pressures, best-corrected distance visual acuity (BCDVA), and postoperative complications were extracted from each patient’s record.
Results: Fifty-one eyes of 51 patients with a mean (standard deviation [SD]) age of 64.66 (6.54) years and a male-to-female ratio of 33 (64.7%) to 18 (35.3%) were included over 10 years. The mean (SD) BCDVA before PPV was 1.87 (0.53) logarithm of the minimum angle of resolution (logMAR), which improved significantly to 0.54 (0.46) logMAR at the final postoperative visit (P < 0.001). The mean (SD) BCDVA was significantly better after early PPV than after late PPV (0.41 [0.30] versus 0.62 [0.52] logMAR; P < 0.05). There was no significant difference in the final BCDVAs among the three methods of lens fragment removal (P > 0.05). The rates of post-PPV complications were as follows: 29 (56.9%) eyes with corneal edema, 16 (31.4%) eyes with uveitis, 10 (19.6%) eyes with cystoid macular edema, 8 (15.7%) eyes with rhegmatogenous retinal detachment, and 8 (15.7%) eyes with other complications (optic nerve atrophy, choroidal neovascularization, vitreous hemorrhage, or epiretinal membrane formation). No significant differences were observed in the rates of complications according to the time interval between complicated phacoemulsification and PPV (all P > 0.05). The frequency of corneal edema was significantly higher when removing lens fragments using the trans-limbal method than using the other methods (P < 0.05), yet the rates of other complications were comparable among the three methods of lens fragment removal (all P > 0.05).
Conclusions: Early PPV and removal of a dropped lens fragment or nucleus resulting from complicated phacoemulsification cataract surgery are recommended to achieve better visual outcomes. Future studies with longer follow-up, greater sample sizes, and analysis of other parameters of visual function, such as contrast sensitivity, visual field, color vision, and stereopsis, could provide more conclusive results and help verify our preliminary findings.
Electroretinogram changes before and after silicone oil removal in eyes with macula-off rhegmatogenous retinal detachment
Evita Evangelia Christou, Paraskevas Zafeiropoulos, Eleni Bagli, Andreas Katsanos, Ioannis Asproudis, Maria Stefaniotou
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 3 (2022), 30 December 2022 , Page 119-127
https://doi.org/10.51329/mehdioptometry160
Background: Pars plana vitrectomy (PPV) with silicone oil (SO) injection for rhegmatogenous retinal detachment (RRD) repair may adversely affect electroretinographic responses. This study was aimed at assessing retinal function using electrodiagnostic testing after successful PPV with SO tamponade in the eyes with macula-off RRD.
Methods: In this interventional comparative study, eligible participants were recruited prospectively over 1 year. We included the eyes that underwent a single successful three-port PPV with SO tamponade for the primary repair of macula-off RRD. Full-field electroretinogram (ffERG) and multifocal electroretinogram (mfERG) were recorded 1 day before and 3 days after SO removal. The amplitude and implicit time of the a- and b-waves for ffERG and P1 and N1 waves for mfERG were evaluated. The unaffected fellow eyes of the patients were selected as controls.
Results: We included the ten eyes of ten patients (seven men and three women) with a mean (standard deviation) age of 58.8 (6.2) years. The mean (SD) interval between the diagnoses of macula-off RRD and PPV was 11.7 (3.6) days. The mean (SD) duration of SO tamponade was 147.8 (34.9) days. Using ffERG, significantly lower a- and b-wave amplitudes were found in the eyes before and after SO removal or compared to the unaffected fellow eyes (all P < 0.05). Using the mfERG, treated eyes had significantly lower P1 amplitudes in the central R1+R2+R3 rings and in the R4 and-R5 peripheral rings of the macular area in the eyes before and after SO removal or compared to the unaffected fellow eyes (all P < 0.05). The wave implicit time in ffERG and mfERG did not differ significantly in the eyes before and after SO removal or compared to the unaffected fellow eyes (all P > 0.05).
Conclusions: The electrical retinal response density in ERG waveforms increased following SO removal, indicating amelioration of the electrical activity of the retina and macula. These results indicate that the adverse effects of SO tamponade on electroretinography responses may be reversible with removal. In addition, ffERG and mfERG can be used to monitor retinal function in the eyes with macula-off RRD and SO tamponade. Further clinical trials are required to verify the preliminary findings of this study.
Summer 2022
Vol. 3 No. 2 (2022)
A brief review of Valsalva retinopathy
Petros Asteris, Dimitrios Kalogeropoulos, George Moussa, Ioannis Iraklis Vitos, Aikaterini Christodoulou, Chris Kalogeropoulos
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 2 (2022), 29 October 2022 , Page 42-47
https://doi.org/10.51329/mehdioptometry149
Background: Valsalva retinopathy is a specific type of retinopathy that appears following an acute rise in intrathoracic or intra-abdominal pressure. This review focuses on current literature and future directions for the diagnosis and management of Valsalva retinopathy.
Methods: In this brief review, the literature was searched to provide an extensive general and updated description of Valsalva retinopathy, focusing on its management and prognosis. Selected articles are summarized to present the etiology, general pathology, pathophysiology, symptoms, signs, diagnosis, differential diagnosis, treatment, and prognosis of Valsalva retinopathy.
Results: The main symptom of Valsalva retinopathy is loss of visual acuity following exertion. This is caused by the rupture of small superficial vessels in the macula and perimacular areas, leading to extravasation of blood. No link between age, sex, or race has been found, although fundus vessel abnormalities pose some predisposition to the disease. During fundoscopy, Valsalva retinopathy appears most frequently as well-defined preretinal hemorrhages confined to the sub-internal limiting membrane (ILM) or subhyaloid space. If ILM rupture occurs, hyaloid hemorrhage can appear. Diagnosis is based on the patient’s medical history and a standard examination. Usually, only observation of the patient is required, with the hemorrhage resolving within weeks to months. In cases of large premacular hemorrhage or large sub-ILM/subhyaloid hemorrhage, vitrectomy or Nd:YAG krypton laser membranotomy can be performed.
Conclusions: Of all the aspects of Valsalva retinopathy that might trouble the physician, the most challenging features are differential diagnosis and the choice of optimal treatment. Therapeutic strategies for Valsalva retinopathy can be either conservative or based on Nd:YAG laser membranotomy and/or vitrectomy. All methods seem to have good outcomes. However, physicians should not be afraid of advancing beyond conservative therapy, especially in the event of persistent premacular hemorrhage, which could lead to permanent retinal damage if valuable time is lost, even after vitrectomy.
Stay-at-home myopia among school children during the COVID-19 pandemic
Moataz A Sallam, Mohammed A Mohammed, Mohamed M Karrar, Ehab M Ghoneim
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 2 (2022), 29 October 2022 , Page 48-54
https://doi.org/10.51329/mehdioptometry150
Background: Uncorrected myopia represents a major cause of visual disability in children, especially in low-income and middle-income countries. However, there is still debate about the effect of e-learning and “stay-at-home” guidelines on the refractive status of school children, especially in the absence of long-term follow-up data. This study aimed to assess the impact of stay-at-home enforcement during the COVID-19 pandemic on myopia progression in students in the Suez Canal Area, Egypt.
Methods: This longitudinal observational study included 1650 students. All students aged 8–15 years with visual complaints, who had attended routine annual vision checks since 2018, were enrolled and assessed annually for myopia progression until 2021. Cycloplegic and noncycloplegic refraction, axial length (AL), corneal curvature, and uncorrected and best-corrected distance visual acuity were measured. The participants were administered a questionnaire that focused mainly on collecting information on their visual habits.
Results: Our study included 3300 eyes of 1650 school students with myopia during the 4-year study period from 2018 to 2021. The mean cycloplegic spherical equivalents (CSE) were – 1.02, – 1.52, – 2.00, and – 3.50 diopters (D) in 2018, 2019, 2020, and 2021, respectively. This myopic shift in CSE over time was significant (P < 0.001). The average keratometric reading (Avg K) increased significantly during the follow-up period (P < 0.001). The Avg K measurements were 42.32, 42.62, 43.02, and 44.19 D in 2018, 2019, 2020, and 2021, respectively. The changes in Avg K were significant (P < 0.001). The mean AL measurements were 22.53, 22.59, 22.69, and 22.71 mm in 2018, 2019, 2020, and 2021, respectively. Although statistically significant (P < 0.001), changes in AL were clinically insignificant throughout the study period. The mean durations spent on electronic devices at home were 2.12, 2.46, 3.10, and 6.00 hours in 2018, 2019, 2020, and 2021, respectively. The changes over time were significant (P < 0.001).
Conclusions: During the COVID-19 pandemic, studying at home accelerated the degree of refraction toward myopia in school children in Egypt. Further studies are needed to assess the academic performance of students with progressive myopia.
Roles, responsibilities, and job description of ophthalmic nurses, a universal definition is required
Pegah Rashidian
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 2 (2022), 29 October 2022 , Page 55-56
https://doi.org/10.51329/mehdioptometry151
Letter to the Editor
Binocular vision parameters in handloom silk weavers
Divyalakshmi Sundaravadivel, Deepa Bangalore Muniyappa Shanmugham
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 2 (2022), 29 October 2022 , Page 57-62
https://doi.org/10.51329/mehdioptometry152
Background: Focusing the gaze for prolonged periods on a fixed distance demands high visual efficiency in handloom silk weavers and might result in various accommodative and vergence dysfunctions. The aim of the present study was to assess accommodative and vergence parameters and determine the frequency of non-strabismic binocular vision anomalies (NSBVAs) among handloom silk weavers.
Methods: In this cross-sectional study, we recruited voluntary handloom silk weavers from the Government-aided Society of Arignar Anna Silk Co-op Society K.H.-1, Kanchipuram, aged 20–39 years. All participants underwent preliminary visual examinations and comprehensive binocular vision testing of accommodative and vergence parameters. Sensory evaluation was performed using stereopsis testing and the Worth 4 Dot test. Motor evaluation included the ocular motility assessment, heterophoria checks for distance and near, near point of convergence, negative and positive fusional vergences for distance and near, vergence facility, negative and positive relative accommodations, both monocular and binocular near points of accommodation, and accommodative facility. The monocular estimate method was used to determine the accommodative response. Quantitative data are expressed as mean (standard deviation [SD]), and qualitative data are expressed as frequency (percentage).
Results: We recruited a total of 72 weavers, including 41 (56.9%) men and, 31 (43.1%) women with mean (SD) age, working hours, and work experience of 34.15 (4.12) years, 9 (2.5) h/day, and 17.5 (6.9) years, respectively. Of the 29 (40.3%) weavers with a refractive error, 18 (25%) had astigmatism; seven (9.7%) had myopia; and four (5.6%) had hyperopia. Of the 72 weavers, 38 (52.8%) presented with NSBVAs, including 13 (18.1%) with accommodative dysfunctions, 11 (15.3%) with vergence dysfunctions, and 14 (19.4%) with combined accommodative and vergence dysfunctions. Accommodative insufficiency was the most prevalent dysfunction among all NSBVAs. Overall, 57 (79.2%) handloom silk weavers reported vision-related symptoms during their weaving hours, all with NSBVAs (n = 38), 19 with normal parameters in the binocular vision test, and 15 with no symptoms.
Conclusions: The frequency of NSBVAs was high among handloom silk weavers compared to the literature. This implies a need for comprehensive binocular vision examination for people in this occupation to rule out NSBVAs for improving their quality of life and occupational productivity. Future large-scale studies are required to determine the exact NSBVAs prevalence among workers of this near vision-related occupation.
Changes in accommodation with visual fatigue among digital device users
Sivaletchumi Sigamani, Chiranjib Majumder, Sheiladevi Sukumaran
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 2 (2022), 29 October 2022 , Page 63-69
https://doi.org/10.51329/mehdioptometry153
Background: Visual fatigue is categorized as a complex phenomenon that decreases visual performance. The aim of the present study was to assess changes in accommodation at different levels of visual fatigue among students of a Malaysian private university using digital devices.
Methods: In this cross-sectional study, students regardless of sex and ethnicity were included. A comprehensive eye examination was performed. After estimating the level of visual fatigue, the amplitude of accommodation (AA), accommodation facility (AF), and monocular estimation method (MEM) were measured. The visual fatigue questionnaire was filled out by the participants. Participants were categorized based on the visual fatigue scores into low, moderate, and high visual fatigue groups. Moderate and severe visual fatigue groups were combined, as the distribution of participants was uneven across the groups. Accommodation parameters were measured for each group and compared between the two groups, i.e., the low visual fatigue group and the combined moderate to severe visual fatigue group.
Results: We enrolled a total of 86 students, including 29 (33.72%) men and 57 (66.28%) women, with a mean (standard deviation [SD]) age of 22.02 (1.51) years and age ranging from 19 to 26 years. By ethnicity, there were 69 (80.23%) Chinese, five (5.81%) Indian, four (4.65%) Malay, and eight (9.30%) participants from other ethnicities. Most participants were in the low visual fatigue group (54.65%), followed by the severe (25.58%) and moderate (19.77%) visual fatigue groups. AA for both eyes and AF for the right eye differed significantly between the two groups of visual fatigue: low (Group 1) and moderate-to-severe (Group 2) (both P < 0.05). None of the accommodative parameters correlated with visual fatigue (P > 0.05).
Conclusions: Binocular AA and monocular AF significantly differed between the visual fatigue groups, but MEM was comparable. However, none of the accommodative parameters correlated with visual fatigue. These perceived vision dysfunctions could affect the visual skills of students. Therefore, future studies on the relationship between the observed dysfunctions and students’ reading performance are necessary.
Unilateral asymptomatic optic disc edema: do not forget sinusitis
Sajeev Cherian Jacob, Lavanya Kalikivayi, Venkataramana Kalikivayi
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 2 (2022), 29 October 2022 , Page 70-74
https://doi.org/10.51329/mehdioptometry154
Background: Optic disc edema is a pathological condition with various causes. Cases of optic disc swelling should be dealt with a multidisciplinary approach to rule out those causes. Unilateral optic disc edema is seen in papillitis, non-arteritic anterior ischemic optic neuropathy, retinal vein occlusion, and infection or inflammation of the contiguous sinus or orbit. Here, we report a rare case of unilateral asymptomatic optic disc edema due to posterior ethmoid sinusitis.
Case Presentation: A 53-year-old man presented for a routine 3-monthly follow-up after an uneventful cataract surgery of the right eye. All examinations were unremarkable, except for the right eye optic disc edema on fundus examination, consistent with an enlarged blind spot in the visual field test. Contrast-enhanced magnetic resonance imaging revealed mucosal thickening with muco-inflammatory exudates of the posterior ethmoidal sinus overriding the optic disc on the right side, leading to optic disc edema of the right eye. The patient was diagnosed with unilateral asymptomatic optic disc edema in the right eye due to posterior ethmoid sinusitis and referred to an otorhinolaryngologist for the management. The otorhinolaryngologist performed functional endoscopic sinus surgery and prescribed antibiotics and anti-histamines for 6 weeks. At the final examination, his visual acuity was 6/6, and the fundus examination revealed no optic disc edema.
Conclusions: We reported a rare case of unilateral optic nerve edema and visual field loss with a treatable cause. Contemporary imaging provided the accurate diagnosis. Therefore, in cases of disc edema, sinusitis of the adjacent paranasal sinuses should be ruled out as a possible cause of compressive optic neuropathy or inflammation overriding the optic nerve.
Spring 2022
Vol. 3 No. 1 (2022)
Current and future perspectives on smart glasses
Kanupriya
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 1 (2022), 24 September 2022 , Page 1-4
https://doi.org/10.51329/mehdioptometry143
Editorial
A review of oculoplastic surgery and ocular surface disorders
Mukaddes Damla Ciftci, Ozlem Barut Selver
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 1 (2022), 24 September 2022 , Page 5-11
https://doi.org/10.51329/mehdioptometry144
Background: Ocular surface health is closely related to the condition of the ocular adnexa, particularly the eyelids. Both ocular adnexal disorders and oculoplastic procedures performed to treat them can cause ocular surface disorders (OSD). In this review, we aimed to summarize the relationship between oculoplastic procedures and OSD.
Methods: In this narrative review, an electronic search of the PubMed/MEDLINE database was conducted using various combinations of keywords including “oculoplastic surgery,” “ocular surface disorders,” “dry eye,” and “management,” without time or language limitations, to include studies concerning oculoplastic surgery and OSD.
Results: We included articles involving oculoplastic procedures and OSD with discussions of preventive approaches and management strategies in this context. For a systematic approach, the preoperative assessments and postoperative treatment of patients were retrieved and summarized. Preoperative preventive measures included evaluation of tear film break-up time, tear osmolarity, tear meniscus area and height measurement by anterior segment optic coherence tomography, lipid layer thickness by interferometer, corneal staining and Oxford Scheme, Schirmer test, blink rate and completeness, ocular surface disease index scoring, eyelid closure, and Bell’s phenomenon. Postoperative assessments included the presence and severity of dry eye and early management of dry eye with artificial tears, topical anti-inflammatory medications, and night taping; evaluation of the presence of chemosis, and, if present, management with pharmacologic, mechanical, or surgical therapies when needed; and prompt detection and treatment of lagophthalmos and consequent exposure keratopathy.
Conclusions: Careful preoperative examination of the ocular surface is mandatory to reduce or eliminate complications after oculoplastic surgery. Ocular surface-related complications that surgeons encounter after oculoplastic surgery should be promptly diagnosed and treated.
Multi-color imaging in a unilateral central retinal artery occlusion following dengue fever: A case report and literature review
Srinivasan Sanjay, Ankush Kawali, Nikhil Gopalakrishnan, Rohit Shetty, Padmamalini Mahendradas
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 1 (2022), 24 September 2022 , Page 12-21
https://doi.org/10.51329/mehdioptometry145
Background: Dengue fever is associated with various sight-threatening ocular manifestations, some of which can occur several months after fever. These include subconjunctival hemorrhage, vitreous hemorrhage, retinal hemorrhage, cotton wool spots, central and branch retinal artery occlusion, central scotoma, papilledema, optic neuropathy, retinal vasculitis, retinitis, retinal pigment epithelium mottling, foveolitis, choroidal effusion, exudative retinal detachment, anterior uveitis, endogenous endophthalmitis, and panophthalmitis. Herein, we report a patient with unilateral central retinal artery occlusion (CRAO) and raised dengue immunoglobulin G (IgG) titers who underwent serial multimodal imaging with fundus photography, spectral domain optical coherence tomography (SD-OCT), optical coherence tomography angiography (OCTA), and multi-color imaging (MCI). Furthermore, we reviewed recent publications highlighting different eye diseases and the role of MCI in their diagnosis and serial monitoring.
Case presentation: A 53-year-old Asian Indian woman complained of blurring of vision in the right eye (OD) two months after a bout of fever. Her best-corrected distance visual acuity was finger counting close to the face in the OD and 20/40 in the left eye. CRAO of the OD was diagnosed. Systemic investigations were normal except for elevated dengue IgG levels. Optical coherence tomography and fluorescein angiography confirmed this diagnosis. MCI and SD-OCT using Spectralis™ performed before and after treatment with oral steroids demonstrated improvement. MCI served as a noninvasive ancillary tool for monitoring the CRAO. In addition to the case report, we summarize articles pertaining to MCI published during the years 2018–2022. The list is not exhaustive but highlights salient features of different retinal and choroidal disorders evaluated using MCI. Our summary highlights the role of MCI in the diagnosis and serial monitoring of eye diseases.
Conclusions: A diagnosis of post-dengue fever retinal artery occlusion should be made after ruling out other causes of retinal artery vascular occlusion. We demonstrated retinal changes using serial imaging. MCI can be a useful tool, along with SD-OCT, to monitor clinical improvement. Optometrists can follow up patients with retinal vascular occlusions using noninvasive methods.
A review of artificial intelligence applications in anterior segment ocular diseases
Zahra Heidari, Mehdi Baharinia, Kiana Ebrahimi-Besheli, Hanieh Ahmadi
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 1 (2022), 24 September 2022 , Page 22-33
https://doi.org/10.51329/mehdioptometry146
Background: Artificial intelligence (AI) has great potential for interpreting and analyzing images and processing large amounts of data. There is a growing interest in investigating the applications of AI in anterior segment ocular diseases. This narrative review aims to assess the use of different AI-based algorithms for diagnosing and managing anterior segment entities.
Methods: We reviewed the applications of different AI-based algorithms in the diagnosis and management of anterior segment entities, including keratoconus, corneal dystrophy, corneal grafts, corneal transplantation, refractive surgery, pterygium, infectious keratitis, cataracts, and disorders of the corneal nerves, conjunctiva, tear film, anterior chamber angle, and iris. The English-language databases PubMed/MEDLINE, Scopus, and Google Scholar were searched using the following keywords: artificial intelligence, deep learning, machine learning, neural network, anterior eye segment diseases, corneal disease, keratoconus, dry eye, refractive surgery, pterygium, infectious keratitis, anterior chamber, and cataract. Relevant articles were compared based on the use of AI models in the diagnosis and treatment of anterior segment diseases. Furthermore, we prepared a summary of the diagnostic performance of the AI-based methods for anterior segment ocular entities.
Results: Various AI methods based on deep and machine learning can analyze data obtained from corneal imaging modalities with acceptable diagnostic performance. Currently, complicated and time-consuming manual methods are available for diagnosing and treating eye diseases. However, AI methods could save time and prevent vision impairment in eyes with anterior segment diseases. Because many anterior segment diseases can cause irreversible complications and even vision loss, sufficient confidence in the results obtained from the designed model is crucial for decision-making by experts.
Conclusions: AI-based models could be used as surrogates for analyzing manual data with improveddiagnostic performance. These methods could be reliable tools for diagnosing and managing anterior segmentocular diseases in the near future in remote areas. It is expected that future studies can design algorithms thatuse less data in a multitasking manner for the detection and management of anterior segment diseases.
Google Lens: A potential cost-effective screening tool for diabetic retinopathy
Pradeep Venkatesh
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 1 (2022), 24 September 2022 , Page 34-38
https://doi.org/10.51329/mehdioptometry147
Background: Diabetic retinopathy (DR) is a major, sight-threatening complication of diabetes mellitus. Blindness from DR can be prevented by successful and proactive screening. However, DR is screened in less than half of the patients because of barriers in availability, affordability, accessibility, and awareness. Although artificial intelligence (AI)-based algorithms are being evaluated for DR screening, they have limitations of infrastructure, accessibility, training, and manpower cost. Therefore, simpler and more practical DR screening tools should be explored.
Hypothesis: Google Lens, an easily available, vision- and AI-based application in most smartphones, is a potential tool for cost-effective DR screening. It recognises images through a visual analysis based on neural networking. Thus, it can recognize retinal disorders, such as DR, in images. The development and adoption of Google Lens-based DR screening would have several advantages over the conventional hospital/specialist/healthcare facility-based approach, including widespread accessibility, acceptable accuracy, reduction in the direct cost of healthcare for patients with diabetes mellitus, and active patient participation in self-care.
Conclusions: DR screening, detection, and grading using Google Lens is a feasible and effective option. Despite current limitations, it could transform DR screening from a costly, hospital- and expert-based method to a cost-effective, self-applicable, and home-based one. However, diagnostic accuracy studies comparing the index test with Google Lens-based screening are required to determine the usability and validity of this proposed screening tool for DR.
Potential therapeutic effects of Celastrol on dry eye disease
Siu Kan Law
Medical hypothesis, discovery & innovation in optometry, Vol. 3 No. 1 (2022), 24 September 2022 , Page 39-41
https://doi.org/10.51329/mehdioptometry148
Letter to the Editor
Winter 2021
Vol. 2 No. 4 (2021)
Add-on therapy with different non-steroidal anti-inflammatory agents in the management of non-infectious, non-necrotizing episcleritis
Omer Ozer, Muhammet Latif Tuncer
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 4 (2021), 15 August 2022 , Page 133-137
https://doi.org/10.51329/mehdioptometry137
Background: Episcleritis is a common ocular inflammatory disease that can cause red eye. It is usually managed using single or combined topical corticosteroids and topical or oral non-steroidal anti-inflammatory drugs (NSAIDs) as directed by clinical response. However, recurrence is possible. This study aimed to compare the effects of add-on therapies using different topical NSAIDs in the management of treatment-naive, non-infectious, non-necrotizing episcleritis.
Methods: Seventy-five eyes of 75 patients with non-infectious, non-necrotizing unilateral episcleritis were included in this study. Patients were allocated to one of three groups based on the NSAID used as add-on therapy: topical diclofenac sodium 0.1% (group D), topical nepafenac 0.1% (group N1), and topical nepafenac 0.3% (group N3). The time to symptom disappearance was defined as the recovery time.
Results: There were no statistically significant differences in age, sex, initial best-corrected distance visual acuity, and intraocular pressure between groups (all P > 0.05). The mean recovery times of groups D and N1 were comparable (12.86 ± 5.35 days and 11.45 ± 5.42 days, respectively) (P > 0.05). However, the mean recovery time of group N3 was significantly shorter (9.70 ± 3.80 days, P < 0.05). Recurrence was observed in only one patient in group N1 at 3 months, and symptoms resolved when the same medication was reinstituted. Furthermore, we noted no side effects during the follow-up period for any of the treatment modalities.
Conclusions: All three topical NSAIDs were effective add-on therapies in the management of non-infectious, non-necrotizing unilateral episcleritis. However, once-daily administration of topical nepafenac 0.3% had a shorter recovery time than topical diclofenac 0.1% and topical nepafenac 0.1%.
Validity of external observation examination by teachers during vision screening for preschool children
Rokiah Omar, Victor Feizal Knight, Asma Ahida Ahmad Zahidi, Nur Zakiah Mohd Saat, Tan Xuan Li
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 4 (2021), 15 August 2022 , Page 138-145
https://doi.org/10.51329/mehdioptometry138
Background: A vision-screening program is effective in prevention of vision impairment. The validity of vision screening conducted by nurses, medical assistants, and teachers has been previously reported. However, the validity of preschool teachers in conducting external eye observations in preschool children has not been widely investigated. This study aimed to determine validity of preschool teachers in conducting external eye observation tests, including the observation of behavior and external eye health, in preschool children.
Methods: In this cross-sectional study, preschool teachers from Kemajuan Masyarakat kindergarten in Klang Valley, Malaysia, were randomly allocated to the study (n = 30) or control (n = 30) groups. The study group underwent theory training with an optometrist and practical sessions with preschool children on vision screening, while the control group received only brief verbal instructions on steps to conduct the screening. After the briefing, teachers from both groups conducted vision screening tests at their kindergartens on preschool children aged 4–6 years. The same vision screening procedure was repeated in the same children by optometrists to verify results of the teachers.
Results: A total of 700 preschool children were screened by 60 preschool teachers and optometrists. Teachers from the study and control groups displayed high validity in screening for external ocular health, including sensitivity (66.67% versus 66.67%), specificity (95.21% versus 95.54%), and negative predictive value (99.41% versus 99.69%). The positive predictive value was slightly higher in the study group (19.05%) than in the control group (11.76%).
Conclusions: Preschool teachers competently observed external eye health in preschool children. A training module for vision screening is important, and a revision of the current training module is needed. Empowering preschool teachers could help in the early detection and intervention necessary in needy children. This could reduce the nationwide prevalence of visual impairments.
Urban inequality: a hypothetic risk factor for myopia
Ali Nouraeinejad
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 4 (2021), 15 August 2022 , Page 146-149
https://doi.org/10.51329/mehdioptometry139
Background: Myopia is a common refractive error with an expected increase in prevalence. Inequalities in access to ocular health care for sight-threatening or life-threatening ocular diseases have been described. Urbanization is a risk factor for both the incidence and progression of myopia; however, socioeconomic inequalities in urban settings are a new concept in myopia incidence.
Hypothesis: Considering the proven impact of inequalities existing in general and ocular health, urban inequality could be a new risk factor for both the incidence and progression of myopia. Inequalities in urban infrastructure vary between countries; however, there are currently various manifestations of urban inequality, and scholars are concerned about intra-urban inequality as a public health risk. Considering the significant influence of urban inequality on health of children, and because myopia develops and progresses faster during childhood, the effect of urban inequality on myopia must be examined. Although urban inequality could be a putative risk factor for myopia, a causal relationship should be investigated. However, myopia is multifactorial in etiology, originating from the interaction of environmental and genetic factors. Thus, causality between urban inequality and myopia should be investigated through a randomized, controlled trial with strict matching of genetic backgrounds and environmental factors.
Conclusions: Several risk factors for myopia have been proposed, and studies have confirmed causal relationships with most of these factors. Considering the proven impact of urban inequality on both general and ocular health, experimental studies are necessary to confirm the possible causal relationship between urban inequality and myopia. Certainly, there will be substantial challenges in the implementation phase.
Effects of mitomycin-C on tear film function following photorefractive keratectomy for mild-to-moderate myopia
Kianoush Shahraki, Sadegh Saeidi, Paria Ghasemi Boroumand, Kourosh Shahraki
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 4 (2021), 15 August 2022 , Page 150-155
https://doi.org/10.51329//mehdioptometry140
Background: Mitomycin C (MMC) is used to prevent corneal opacity after photorefractive keratectomy (PRK). This study sought to determine the effect of MMC on tear film function after PRK in eyes with mild-to-moderate myopia.
Methods: This prospective, contralateral eye comparison was conducted on 30 eyes of 15 patients with low-to-moderate myopia referred to Alzahra Eye Hospital, Zahedan, Iran. The eyes of the control group underwent PRK with a balanced salt solution, while the fellow eyes in the intervention group underwent PRK with 0.02% MMC for 25 s. The tear breakup time test (TBUT) and basic Schirmer test results of eyes in the control and intervention groups were compared at baseline and 1, 3, and 6 months postoperatively. Tear osmolarity was recorded and compared at baseline and 3 months postoperatively.
Results: The mean ± standard deviation (SD) age of participants was 27.53 ± 7.04 years. No statistically significant differences were observed in the means ± SDs for tear osmolarity, TBUT, and basic Schirmer test values (all P > 0.05) between MMC-treated eyes and untreated fellow eyes at baseline and during postoperative follow-up. The means ± SDs for tear osmolarity, TBUT, and basic Schirmer test results were comparable in both groups between the baseline and postoperative follow-ups (all P > 0.05).
Conclusions: Single application of a standard dose of MMC (0.02%) for 25 s in PRK did not change tear stability, tear production, or variation in tear dynamics up to 6 months postoperatively in eyes with low-to-moderate myopia. Future longitudinal studies with a longer follow-up and a larger sample size are warranted to confirm our findings.
Levator palpebrae superioris function and corneal astigmatism in university students with normal eyelid morphology
Chin Chun Tat, Chiranjib Majumder, Sheiladevi Sukumaran
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 4 (2021), 15 August 2022 , Page 156-160
https://doi.org/10.51329/mehdioptometry141
Background: Eyelids have been shown to influence corneal shape. The effects of eyelid pathologies on corneal astigmatism have been widely investigated. This study aimed to determine the correlation between levator palpebrae superioris (LPS) muscle function and with-the-rule (WTR) corneal astigmatism in university students with normal eyelid morphology.
Methods: This was a cross-sectional study with a sample of 58 university students of Chinese origin selected by simple random sampling at the University College Sedaya International (UCSI) University Optometry Clinic, Kuala Lumpur, Malaysia. We included participants aged 18 to 30 years, regardless of sex, with normal eyelid morphology, normal LPS function, and WTR corneal astigmatism. For LPS muscle function, the distance of the upper eyelid margin from the maximal downgaze to the upgaze was measured, while the frontalis function was negated by the thumb of the examiner. Corneal astigmatism was measured using a manual Keratometry (Topcon OM-4; Topcon Corporation, Tokyo, Japan).
Results: Of the 58 participants, 23 (39.7%) were men and 35 (60.3%) were women. The mean ± standard deviation (SD) age was 23.22 ± 1.77 years. For all participants, the means ± SDs for LPS muscle function and corneal astigmatism were 14.72 ± 1.74 mm and – 1.16 ± 0.47 D, respectively. Of the 58 participants, 25 and 33 had low and moderate WTR corneal astigmatism, respectively. The mean LPS muscle functions were not significantly different between the low and moderate WTR corneal astigmatism groups (P > 0.05). A positive but statistically insignificant correlation (r = + 0.14; P > 0.05) was found between LPS muscle function and WTR corneal astigmatism.
Conclusions: We found no significant difference in the mean LPS muscle function between low and moderate WTR corneal astigmatism groups in young university students of Chinese origin with normal eyelid morphology. Furthermore, no significant correlation was found between LPS muscle function and low-to-moderate WTR corneal astigmatism.
Race in the phenotype of the glaucoma; a genotypic or an environmental variance?
Pegah Rashidian
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 4 (2021), 15 August 2022 , Page 161-162
https://doi.org/10.51329/mehdioptometry142
Letter to the Editor
Fall 2021
Vol. 2 No. 3 (2021)
Binocular vision parameters in chronic heavy alcoholics: Short-term outcomes of alcohol detoxification
Kala Nagaraj, Vandana Kamath, Aditya Goyal
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 3 (2021), 14 March 2022 , Page 94-101
https://doi.org/10.51329/mehdioptometry131
Background: Alcohol consumption is rising in developing countries such as India, and alcohol addiction has systemic and ocular impacts. This study aimed to investigate the binocular functions of chronic heavy alcoholics before and after alcohol detoxification.
Methods: A prospective before–after study was designed and conducted at Treda De-Addiction Centre, Bengaluru, India. Males in the age range of 30–40 years who had been alcohol addicts for more than six years and met the inclusion criteria were recruited. We performed a routine optometric examination followed by detailed binocular vision assessment, including accommodative, vergence, and oculomotor tests on the first day of rehabilitation and one month after initiation of rehabilitation.
Results: Twenty-five males with of the age (mean ± standard deviation [SD]) 36.24 ± 4.33 years were evaluated. The pre- and post-detoxification mean ± SD of the monocular (right eye: 5.98 ± 3.50, 6.60 ± 3.49; left eye: 6.18 ± 3.69, 7.10 ± 3.78) and binocular accommodative facility (7.10 ± 3.93, 7.40 ± 4.51) did not change significantly (all P > 0.05). Eighteen (72%) of the participants had non-strabismic binocular vision anomalies (NSBVA), among whom the accommodative infacility and convergence insufficiency were higher in frequency and remained constant after alcohol detoxification. Furthermore, the binocular vision parameters showed no statistically significant difference between the pre- and post-detoxification values (all P > 0.05).
Conclusions: The binocular vision parameters did not change significantly after one month of alcohol detoxification in the chronic heavy drinkers. Most long-term alcoholics had NSBVA with no change after rehabilitation, indicating that short-term alcohol detoxification may not aid in the recovery of binocular parameters. However, further validation is required. Assessing the impact of vision therapy in addition to a longer period of abstinence can confirm or refute the persistence of observed effects of chronic alcohol consumption on binocular functions and NSBVA in this population.
Visual snow: A neuro-ophthalmic syndrome
Valeria Albano, Silvana Guerriero, Giovanni Alessio
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 3 (2021), 14 March 2022 , Page 102-107
https://doi.org/10.51329/mehdioptometry132
Background: The visual snow syndrome (VSS) is a rare disease characterized by persistent positive visual phenomena that are enigmatic and may be underestimated. It manifests as the perception of tiny, simultaneous, diffuse, and mobile dots frequently throughout the visual field. Although it affects brain networks, ocular examination is also indicated. This paper was aimed to review recent studies on VSS to identify the best clinical approach.
Methods: In this narrative review, PubMed/Medline, Directory of Open Access Journals, and Embase were searched using the following terms: “Visual snow”, “Persistent aura”, “Persistent positive visual phenomena”, “Visual aura”, “Migraine”, “TV static”, “Migraine aura status”, and “Visual disturbance”. We searched relevant publications from January 2014 to January 2021 to find the best clinical approach.
Results: VSS may be reconstituted as a distinct entity, although the symptoms may be consistent with typical migraine visual aura. For approximately two-thirds of patients, symptoms worsen and reduce their ability for activities of daily living. It often causes psychogenic detriment of the patient and their capacity to function socially and vocationally. Comprehensive history-taking and ocular examination are required to rule out other causes. However, all ocular and radiological findings may be normal.
Conclusions: VSS is a neuro-ophthalmic disorder characterized by continuous chronic and recurrent visual disturbances that involve the entire visual field and may respond to empiric antimigraine or anti-seizure treatments. It may reduce the ability for activities of daily living; therefore, proper diagnosis by eye care professionals is necessary to determine its diagnosis and management.
Visual outcomes after management of bilateral cataract and retinal detachment in atopic dermatitis
Sofia Noreen, Konstantinos Katsikatsos, Alia Al-Mousawi, Dimitrios Kalogeropoulos, Ash Sharma, Kim Son Lett, Arijit Mitra, Soon Wai Ch’ng
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 3 (2021), 14 March 2022 , Page 108-113
https://doi.org/10.51329/mehdioptometry133
Background: Atopic dermatitis (AD) is a chronic pruritic inflammatory skin disorder of childhood with a broad spectrum of ocular manifestations, including keratoconjunctivitis, keratoconus, cataract, and rhegmatogenous retinal detachment (RRD). This study was aimed at reporting the visual outcomes in patients with bilateral cataract and RRD in the context of AD.
Methods: This was a retrospective, observational case series. A thorough history, clinical features, and surgical management of seven consecutive patients who presented to the Birmingham and Midland Eye Centre with bilateral cataract and RRD secondary to severe AD were investigated.
Results: Fourteen eyes of seven patients with AD were analyzed. Twelve of the 14 eyes had cataract (85.7%). Seven patients had anterior or posterior subcapsular cataract (58.3%); 13 of the 14 eyes had RRD (92.8%). Most cases were bilateral or simultaneous (85.7% and 71.4%, respectively). Eight eyes had involvement of the temporal quadrant (61.5%): three eyes had giant retinal tears (23%) and five eyes with proliferative vitreoretinopathy (38.5%). Three eyes underwent scleral buckle surgery with or without cryotherapy (21.4%), and eight eyes had PPV (57.1%) combined with other procedures. Two eyes (15.4%) had persistent RRD postoperatively. The latest recorded postoperative best-corrected distance visual acuity was 6/36 or better in 10 (71.4%) eyes.
Conclusions: Temporal RRD was commonly observed in retinal detachment secondary to AD. Surgical repair was often challenging because of proliferative vitreoretinopathy and significant cataract. A further multidisciplinary study involving dermatologists would be helpful in identifying a larger high-risk population for AD and earlier detection of asymptomatic retinal tears or holes, which would allow preventive treatment and limit sight-threatening complications.
Chitosan-coated contact lens-based ophthalmic drug delivery system to manage Acanthamoeba keratitis: A preliminary hypothesis
Masoud Sadeghi, Parastoo Tajzadeh, Siamak Zarei-Ghanavati, Mohsen Arefnezhad
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 3 (2021), 14 March 2022 , Page 114-118
https://doi.org/10.51329/mehdioptometry134
Background: Acanthamoeba species can cause devastating contact lens (CL)-related microbial keratitis. Its culture is less sensitive, and little evidence is available for the safety or efficacy profile of medications. Therefore, early diagnosis and optimal treatment remain difficult. The aim of this study was to present the hypothesis that a novel chitosan-coated CL-based ophthalmic drug delivery system has therapeutic and prophylactic effects on acanthamoeba keratitis.
Hypothesis: CL-based drug delivery is a popular sustained-release drug delivery that extends the drug release time, thus increasing its bioavailability and treatment efficacy. Chitosan, a derivative of chitin, has antioxidant and broad-spectrum antimicrobial properties against fungi, yeasts, and bacteria. It acts against microbial cells; however, whether its mechanism of action is microbiostatic or microbicidal remains unknown. It exhibits wound healing and film-forming properties. Chitosan composite films permit high transmittance of visible light, making it transparent and therefore desirable for the development of CLs. Chitosan/Ag/ZnO blend films exhibit antimicrobial activities. Further, soft CLs coated with chitosan, sodium hyaluronate, polylysine hydrobromide, and sodium alginate show drug delivery properties and reduced bacterial growth. Recently, concentration-dependent anti-amoebic activities of chitosan and nano-chitosan against the trophozoite and cystic forms of Acanthamoeba have been reported. Based on the existing evidence, we hypothesized that a chitosan-coated CL-based ophthalmic drug delivery system could have therapeutic and prophylactic effects on acanthamoeba keratitis or subsequent endophthalmitis.
Conclusions: CLs or intraocular implants with chitosan-based nanocoatings alone or in combination with routine treatment may be preventive or therapeutic for acanthamoeba keratitis or endophthalmitis. Experimental studies and further clinical trials are required to explore the efficacy and safety profile. Moreover, randomized controlled trials in healthy eyes with soft or hard CLs or orthokeratology lenses for refractive error correction may shed light on the prophylactic effect of this novel drug delivery system. Other forms of ophthalmic drug delivery systems using chitosan-based nanocoatings should be studied additionally.
Causative link between coronavirus disease vaccination and central serous chorioretinopathy: Reality or illusion?
Fatemeh Heidary, Reza Gharebaghi
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 3 (2021), 14 March 2022 , Page 119-123
https://doi.org/10.51329/mehdioptometry135
Background: Most COVID-19 vaccines were authorized for emergency use. Despite a large number of vaccines that have been administered, adverse ocular effects have been reported. This paper summarized the reports about central serous chorioretinopathy (CSCR) following coronavirus disease vaccination.
Methods: In this short communication, we have included relevant publications about CSCR after coronavirus disease vaccination from the beginning of the pandemic until January 2022.
Results: The CSCR occurrence after vaccination has been reported for many years. However, a few studies are available about CSCR after coronavirus disease vaccination. Most cases revealed the development of CSCR within one week of vaccination that subsequently resolved.
Conclusions: The timeline of the CSCR diagnosis developing a few days after vaccination suggests a causative link. However, in view of the millions of administered doses of vaccines along with boosters, the causative link between CSCR and vaccines remains uncertain. Additional studies are needed to confirm a causal claim.
Blue light-blocking efficiency of blue light-blocking and driving spectacle lenses
Bon-Yeop Koo, Myoung-Hee Lee
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 3 (2021), 14 March 2022 , Page 124-132
https://doi.org/10.51329/mehdioptometry136
Background: Retinal damage caused by blue light can result in glare, decreased visual acuity, and accelerated macular degeneration. In clinical practice, blue light-blocking glasses, such as driving glasses, are used to block blue light effectively. This study was aimed at measuring light transmittance to analyze the blue light-blocking efficiencies of blue light-blocking and driving spectacle lenses manufactured with tinting, coating, and only materials and at distinguishing the difference between the two spectacle lenses.
Methods: Blue light-blocking and driving spectacle lenses used to measure light transmittance were manufactured with tinting (blue light blocking lenses by tinting or “BTL” and driving spectacle lenses by tinting or “DTL,” respectively), coating (blue light blocking lenses by coating or “BCL” and driving spectacle lenses by coating or “DCL,” respectively), and only materials (blue light blocking lenses by material or “BML” and driving spectacle lenses by material or “DML,” respectively).
Results: Compared to BTL, DTL had a significantly greater decrease in the light transmission efficiency for visible and blue lights (P < 0.05). The blue light hazard function was lower for BML and DML than for conventional coating lenses in both visible and blue lights, although without significant differences between visible and blue lights (P > 0.05).
Conclusions: The blue light-blocking spectacle lenses had the highest blue light-blocking efficiency when manufactured with tinting, coating, and only materials, in order. With DML, the blue light-blocking efficiency was lower compared to DTL but higher compared to DCL. Therefore, DML could provide a balanced glare control and clear retinal image overall.
Summer 2021
Vol. 2 No. 2 (2021)
Intravitreal injections during the COVID-19 pandemic era
Selda Celik Dulger, Mehmet Citirik, Esra Bahadir Camgoz, Mehmet Yasin Teke
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 2 (2021), 21 November 2021 , Page 50-55
https://doi.org/10.51329/mehdioptometry125
Background: This study aimed to evaluate the clinical characteristics and changes in the number of patients receiving intravitreal injections (IVIs) at a tertiary hospital during the coronavirus disease 2019 (COVID-19) pandemic as compared to the pre-pandemic period.
Methods: This retrospective, cross-sectional study included 3,211 patients with retinal disease, who received IVIs of anti-vascular endothelial growth factor (anti-VEGF) between January and May 2020. This 5-month period was divided into a pre-pandemic and a pandemic period. Clinical and demographic data were collected and were compared between the patients in each period. All COVID-19 infection precautions were implemented to minimize the potential transmission of COVID-19 to both healthcare workers and patients.
Results: A total of 3,211 IVIs were administered to patients with diabetic retinopathy, age-related macular degeneration, retinal vein occlusion, and other retinal conditions. Diabetic retinopathy was the most common indication for treatment in the pre-pandemic as well as pandemic periods. Bevacizumab (Avastin, Roche) was the most common IVI type, followed by aflibercept (Eylea, Bayer). Of 3,211 IVIs, 2,943 (91.7%) were administered during the pre-pandemic period and 268 (8.3%) during the pandemic period. There was a statistically significant decrease in injections between the pre-pandemic and pandemic periods, with an overall reduction of 90.8% in IVIs (P < 0.05). No cases of confirmed transmission of COVID-19 orcomplications associated with IVIs were recorded.
Conclusions: This study showed that the number of IVIs and patient visits decreased significantly, by more than 10-fold, during the lockdown period. These findings show that COVID-19 has turned the management of sight-threatening eye diseases into a challenging process and must be addressed if future healthcarerestrictions are imposed.
Biometric changes after vitrectomy with silicone oil tamponade
Simin Hosseini, Amir Faramarzi, Siamak Moradian, Mehdi Yaseri
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 2 (2021), 21 November 2021 , Page 56-62
https://doi.org/10.51329/mehdioptometry126
Background: The Lenstar LS 900 (Haag-Streit AG, Koeniz, Switzerland) is an optical biometer, and its measurements are highly repeatable and precise in cataractous eyes. This study investigated changes in biometric parameters, including axial length (AL), anterior chamber depth (ACD), lens thickness (LT), vitreous cavity depth (VD), and central corneal thickness (CCT) before and after three-port 23-Gauge pars plana vitrectomy with silicone oil tamponade.
Methods: This was a prospective follow-up study. Patients who were scheduled for surgery underwent a detailed slit-lamp examination and objective cycloplegic refraction preoperatively. In eligible cases, the Lenstar LS 900 was used to measure biometric parameters. At the 1-month postoperative follow-up, we repeated the same assessments for the silicone oil (SO)-filled eyes. Data were analyzed to assess the significance of changes and to test the possible correlation of values between the two time points.
Results: Twenty-three patients with a mean ± SD age of 60 ± 12 years completed the study. Postoperatively, we found a significant increase in AL and a decrease in ACD and CCT (all P < 0.05), with no significant changes in LT and VD. A significant correlation was found for ACD, CCT, and cylinder values between the two time points (all P < 0.05). Postoperatively, the spherical and cylindrical components of refraction demonstrated a hyperopic shift, but did not change statistically significantly.
Conclusions: The Lenstar LS 900 underestimated the ACD and overestimated the AL in SO-filled eyes when comparing pre- and postoperative values, in phakic as well as pseudophakic eyes. In planning for cataract surgery in this group of patients, it is more reasonable to calculate IOL power based on the biometric data of the fellow eye, although this may not eliminate possible errors. Further studies with a larger sample size, longer follow-up, and robust study design are necessary to confirm our preliminary results.
Comparison of CSV-1000 and Metrovision contrast sensitivity tests in normal eyes
Abolfazl Tahkor, Javad Heravian Shandiz, Abbas Azimi Khorasani, Alireza Ansari Moghadam
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 2 (2021), 21 November 2021 , Page 63-70
https://doi.org/10.51329/mehdioptometry127
Background: Measuring contrast sensitivity (CS) allows a better understanding of the visual performance of the human eye. This study aimed to examine the correlation and agreement between the results of two sinewave grating-based CS measurement methods, Metrovision and CSV-1000, in normal eyes.
Methods: This cross-sectional, comparative study was performed between December 2018 and April 2019, at an optometry clinic. Subjects underwent comprehensive ocular examinations, which included pupil reflexes, subjective refraction, external eye examinations, smooth pursuit eye movement assessment, the cover–uncover test, and detailed slit-lamp examination of the anterior and posterior segments. Metrovision and CSV-1000 were employed to assess CS under photopic conditions. The correlation and agreement of the results of the two tests were evaluated.
Results: CS was measured for 104 normal eyes for 3, 6, 12, and 18 cycles per degree (cpd) spatial frequencies (participants’ mean age ± standard deviation: 37.3 ± 26.4 years). The CSV-1000 measurements were significantly higher for the 3 and 6 cpd spatial frequencies (both P = 0.01); however, at higher spatial frequencies, CS scores were similar. The highest and lowest differences between the two tests were recorded for the 3 cpd spatial frequency and 18 cpd spatial frequency, respectively. Except for the 3 cpd spatial frequency, in both eyes, the findings correlated significantly between the CSV-1000 and Metrovision (P < 0.05). The narrowest and widest limits of agreement between the two tests were found for the 12 and 3 cpd spatial frequencies, respectively.
Conclusions: The CSV-1000 method estimated CS higher than the Metrovision method, mostly at lower spatial frequencies. Furthermore, the agreement between the two methods was greater at higher spatial frequencies than at lower frequencies. This should be kept in mind when using the two methods interchangeably in visual screening.
The effect of tamarind seed polysaccharide containing eye drop in dry eye syndrome: Results of an interventional, comparative, clinical study
Naser Nozari, Shahrokh Ramin
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 2 (2021), 21 November 2021 , Page 71-76
https://doi.org/10.51329/mehdioptometry128
Background: The mainstay of dry eye treatment is artificial tear solutions. Contralateral eye comparison of 2 types of artificial tears (Xiloial; tamarind seed polysaccharide-containing lubricant eye drop versus Tearlose) in managing dry eye disease was sought in this study.
Methods: This study was a prospective, interventional, contralateral eye comparison of 2 types of artificial tears used for managing dry eye disease. The study participants were categorized into mild (13–22 points), moderate (23–32 points), or severe (33–100 points) ocular surface disease according to the baseline ocular surface disease index (OSDI) questionnaire score. Schirmer I and tear film break-up time (TBUT) tests, as well as detailed slit-lamp examinations, were performed at baseline and at the end of the study. All participants received Xiloial monodose eye drops for the right eye and Tearlose eye drops for the left eye, administered as a single drop 4 times per day. Furthermore, they were instructed to perform lid hygiene every 12 hours per day for both eyes.
Results: Thirty-five patients (70 eyes) with a mean ± standard (SD) age of 50.2 ± 13.4 years were included, and 14 (40%) were men. The mean ± SD of the OSDI score was 44.24 ± 22.59 at baseline. Of the 35 patients, 10 (28.6%), 5 (14.3%), and 20 (57.1%) had mild, moderate, and severe ocular surface disease, respectively, according to the baseline OSDI score. Compared to baseline, the mean values of both TBUT and Schirmer I tests improved significantly in both groups (both P < 0.001). In comparing the final mean values between the 2 groups, this improvement was comparable for the Schirmer I test (P = 0.179), but TBUT in Tearlose-instilled eyes improved significantly more than in the fellow eyes (P < 0.001).
Conclusions: Both Xiloial and Tearlose eye drops improved tear stability and tear production after a 2 week treatment period in eyes with dry eye disease. This improvement was comparable for tear production, but Tearlose-instilled eyes showed significantly greater improvement in tear stability. Further studies with longer follow-up and larger sample sizes could provide more reliable results as a basis for the clinical use of this TSP-containing lubricant eye drop solution in dry eye disease.
The potential retinal hazards of curing light use for dentists
Nicole M Putnam, Sara Thomas, Grace Liao, Emily Bennett, Anne Breen, Miranda Hueners, Lexi Korsten, James Mills, Ibrahim Mohsin, Miles Poole, Shelby Rookstool, Hala Siddiqui, Kelsie Sommerfield, Roni E Kozlowski, John C Mitchell, Denise Mills, Michael Robert Kozlowski
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 2 (2021), 21 November 2021 , Page 77-84
https://doi.org/10.51329/mehdioptometry129
Background: Many recent studies have focused on the potential hazards of blue light exposure to ocular health. One group with a unique blue light exposure risk is dentists, who use curing lights that emit intense blue light during restorative procedures. During these procedures, dentists often experience brief ocular exposure to these lights. The purpose of the present study was to explore whether such exposures may have an effect on the vision and ocular health of dentists.
Methods: A group of 12 dentists who had experienced curing light exposure over a period of 10 or more years were compared to a group of eight control subjects with no such exposure. The subjects were tested for visual acuity and contrast sensitivity. Their retinas were examined using fundus imaging and optical coherence tomography. Macular pigment optical density was measured. The likelihood that brief blue light exposure could lead to ocular effects was further explored by subjecting a retinal pigment epithelial cell (RPE) line to such exposures.
Results: Although no visual defects or ocular pathologies were found in either group, the dentist group differed from the control group in having increased macular thickness (P < 0.02), a higher incidence of macular vessel tortuosity (P < 0.05), and greater variance in their macular pigment optical density values (P < 0.01). RPE cells that received blue light exposure similar to those sustained by dentists demonstrated a change in physiology.
Conclusions: Retinal changes were found in dentists, which, while not pathological in themselves, are associated with some retinal pathologies. Further studies are necessary to determine whether these signs correlate with the degree of curing light exposure and to determine whether they eventually develop into pathological conditions.
Comparison of visual aids for improving reading performance in children with dyslexia
Rokiah Omar, Noor Halilah Buari, Chiranjib Majumder, Victor Feizal Knight
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 2 (2021), 21 November 2021 , Page 85-93
https://doi.org/10.51329/mehdioptometry130
Background: Dyslexia is a key learning disorder associated with reading difficulties in children. The purpose of this study was to determine the effectiveness of simple visual devices in improving the reading performance of children with dyslexia.
Methods: A case control study was conducted by selecting 80 school children with dyslexia, aged 8 to 11 years, from the Special Dyslexic School Program of the Ministry of Education (MOE) Malaysia. Subjects were randomly assigned to four groups: the typoscope, magnifier, visual tracking magnifier (VTM), and control groups. Reading performance was measured based on reading speed and reading error rate. The time taken to complete reading of text was measured, and reading errors were recorded. The reading performance of each group was assessed at baseline, week 2, week 6, and week 12.
Results: Reading performance was significantly different (P < 0.05) for both Level 1 and Level 2, before and after intervention only in children with dyslexia using magnifiers and VTM. Reading performance for children with dyslexia using a magnifier or a VTM increased significantly (P < 0.05) from baseline to week 2, week 6, and week 12. The improvement in reading speed was 2.5 times faster for children in the VTM group than in the other groups.
Conclusions: Simple visual aids, such as a VTM and magnifying glass, improved reading performance in children with dyslexia. The VTM intervention yielded the greatest improvement after 12 weeks of intervention. Hence, it is suggested that a VTM be used as part of a rehabilitation program for all children with dyslexia in Malaysia, particularly those in dyslexia programs in schools under the MOE Malaysia. However, future studies with longer follow-up periods are needed to confirm the sustainability of this improved reading performance after discontinuation of the intervention.
Spring 2021
Vol. 2 No. 1 (2021)
Outcomes of phacoemulsification on the corneal endothelium in diabetic versus non-diabetic patients: A prospective non-randomized controlled interventional study
Alaa Mahmoud, Ismail Moussa, Mortada Abozaid, Mohammed Iqbal
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 1 (2021), 16 June 2021 , Page 1-7
https://doi.org/10.51329/mehdioptometry119
Background: Cataract surgery in patients with diabetes is indicated either to improve visual acuity or to allow assessment and treatment of fundus changes. We aimed to document the effects of phacoemulsification on the corneal endothelium in patients with or without diabetes.
Methods: This comparative, prospective, non-randomized controlled interventional study was conducted in patients with visually significant immature senile cataracts in the ophthalmology department at Sohag University Hospital between January 2018 and December 2020. The following data were recorded: corrected distance visual acuity, keratometry readings, refraction, slit lamp examination results, and biometry data. Changes in corneal parameters were documented preoperatively and at 1, 3, and 6 months postoperatively using specular microscopy.
Results: Sixty-four eyes of 64 patients with visually significant senile cataracts were included (32 eyes in the diabetic group and 32 eyes in the non-diabetic control group). We found greater mean endothelial cell loss in the non-diabetic group (179 cells/mm2; 6.4%) than in the diabetic group (134 cells/mm2; 4.8%) at 3 months postoperatively, yet the difference was not significant. The difference could be explained by the higher mean cumulative dissipated energy (CDE) used in the non-diabetic group (5.37 J) than in the diabetic group (4.68 J), although the difference was also not significant. Moreover, we found significantly higher coefficient of variation (CV) in the non-diabetic group than in the diabetic group at 1, 3, and 6 months postoperatively (P = 0.03, P = 0.02, and P = 0.008, respectively).
Conclusions: Endothelial cell density was directly related to the CDE of phacoemulsification and not to diabetes. CV was significantly higher in the non-diabetic group than in the diabetic group. Future studies with a larger sample size, longer follow-up, and more diabetic subgroups with different levels of glycemic control are warranted to verify our conclusions.
Pharmaceutical treatment of primary open angle glaucoma
Mashael Al-Namaeh
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 1 (2021), 16 June 2021 , Page 8-17
https://doi.org/10.51329/mehdioptometry120
Background: Glaucoma is a progressive, irreversible optic neuropathy that results in serious vision loss and blindness. This review aimed to summarize key concepts of primary open angle glaucoma (POAG) pharmaceutical treatment trials over the last decade.
Methods: We searched PubMed/MEDLINE and clinicaltrials.gov from January 1, 2010, to August 31, 2020, using the key words “POAG” and “Ocular topical therapeutics”. This search yielded 77 and 120 papers, respectively.
Results: Thirty-three records were compatible with our inclusion criteria. Pharmaceutical treatment is a common intervention in POAG for lowering IOP. Prostaglandin (PG) analogues are most commonly recommended as initial medical therapy, which are administrated either as a monotherapy or in combination with other IOP-lowering classes of medications. Alternative therapies, such as beta-blockers, alpha-2 adrenergic receptor agonists, and topical carbonic anhydrase inhibitors, have been used in combination or as a monotherapy. Rho-kinase inhibitors, such as netarsudil 0.02%, AR-13324 0.02%, and ripasudil are new IOP-lowering medications. Despite IOP reduction, there is a significant number of patients with POAG that may experience disease progression, and the risk of blindness over the long term is considerable.
Conclusions: Clinical trials have indicated that pharmaceutical treatment of POAG is effective and safe. In addition, the new novel Rho-kinase inhibitors have shown significant IOP reduction. The new fixed combinations have also yielded significant reductions in IOP. POAG is a cause of irreversible vision loss, if not diagnosed and treated early. The condition is likely to progress in a significant number of patients, with a considerable risk of blindness in the long-term.
The prevalence of amblyopia in 7–9-year-old schoolchildren in Mashhad
Saeed Shahpary, Shahrokh Ramin, Abbas Azimi, Mohsen Heyrani
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 1 (2021), 16 June 2021 , Page 18-23
https://doi.org/10.51329/mehdioptometry121
Background: To determine the prevalence of amblyopia in schoolchildren aged 7–9 years old in Mashhad, Iran.
Methods: This was a cross-sectional, community-based study with schoolchildren aged 7–9 years old. We randomly selected 20 of 189 elementary schools (three schools per district; 10 male-segregated and 10 female-segregated schools) from a proportional combination of public schools across Mashhad. Basic vision exams were performed. If amblyopia was suspected, children underwent supplementary vision exams. The diagnostic criterion for amblyopia was a best corrected visual acuity (BCVA) in one or both eyes equal to or worse than 20/40 or an interocular difference of more than two lines in BCVA without any significant organic pathology.
Results: A total of 2831 children were included in the study. All children were examined comprehensively by an optometrist, and amblyopia was detected in 49/2831 (1.7% [95% CI, 1.22-2.18]). Of the 49 children with amblyopia, 20 (40.8%) were amblyopic in the right eye, 9 (18.4%) in the left eye, and 20 (40.8%) in both eyes. Twenty-four (49%) were first graders, 15 (30.6%) were second graders, and 10 (20.4%) were third graders. The most prevalent subtype of amblyopia was anisometropic amblyopia (57.1%, [95% CI, 43.24-70.96]).
Conclusions: Considering the prevalence of amblyopia among schoolchildren aged 7–9 years old (1.7%), timely detection of amblyopia through preschool screening programs is essential for early treatment or prevention of further visual impairment during childhood.
Diagnostic and therapeutic approaches to optic disc pit maculopathy in children
Dimitrios Kalogeropoulos, Ioannis Asproudis, Soon Wai Ch’ng, Arijit Mitra, Ash Sharma, Konstantinos Katsikatsos, Christopher Asproudis, Chris Kalogeropoulos
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 1 (2021), 16 June 2021 , Page 24-35
https://doi.org/10.51329/mehdioptometry122
Background: Optic disc pit (ODP) is a rare congenital defect of the optic disc that can lead to maculopathy and gradual visual impairment. This review summarizes our current knowledge on the diagnostic and therapeutic approaches to ODP maculopathy (ODP-M) in children.
Methods: A thorough literature search was performed using the PubMed/MEDLINE database from 1960 to 2020. An additional search was conducted using Google Scholar for completeness.
Results: ODP-M is characterized by the accumulation of subretinal and/or intraretinal fluid. The exact pathogenetic mechanisms are not fully understood, and the origin of the fluid remains unknown. Although ODP-M is more likely to occur during the third or fourth decade of life, cases of children with serous retinal detachment have been recorded. Early diagnosis of ODP-M and prompt, appropriate management are crucial, particularly in patients of amblyogenic age. In adults, ODP-M may resolve spontaneously, but most cases require surgical intervention to prevent permanent loss of vision. However, the fact that ODP-M may spontaneously resolve in children cannot be ignored. Various surgical methods have been described, including pars plana vitrectomy (PPV) combined with various techniques, including laser photocoagulation, intravitreal gas injection, and macular buckling.
Conclusions: PPV remains the mainstay surgical approach for ODP-M. However, ODP-M may differ between children and adults. Children constitute a unique population of patients that require a different and probably more tailor-made approach. Detailed clinical examination, combined with a thorough analysis of retinal imaging, may improve our understanding of the background and pathophysiology of the disease and eventually provide us with new insights into the management of ODP-M in the pediatric population.
Vision screening among hearing-impaired school children in Biratnagar, Nepal
Sanjay Kumar Sah, Renu Thakur, Pankaj Ray Adhikari
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 1 (2021), 16 June 2021 , Page 36-40
https://doi.org/10.51329/mehdioptometry123
Background: The prevalence of hearing impairment in Nepal is 16.5%, affecting approximately 2.71 million people. Deaf children are visually dependent, and even a mild refractive error may cause visual discomfort. The goal of this study was to determine the need for vision screenings in schools for the hearing impaired in Biratnagar, Nepal.
Methods: A cross-sectional study was conducted with permission from Birat Deaf Secondary School, Biratnagar, Nepal. A total of 130 hearing-impaired students were examined. Non-invasive, comprehensive optometric examinations were performed to detect visual disorders. When a more detailed evaluation was needed, the students were referred to the Pediatric Ophthalmology Department, Biratnagar Eye Hospital Biratnagar, Nepal.
Results: Of the 130 hearing-impaired students, 58 (44.6%) were male and 72 (55.4%) were female. The mean ± standard deviation of age was 16.03 ± 3.8 years (range 6–25 years). Twenty-one (16.1%) students had refractive errors: 13 (10%) had myopia, 7 (5.4%) had hyperopia, and 1 (0.8%) had anisometropia. In the cover test, 88 (67.7%) had orthophoria, 19 (14.6%) had exophoria, 11 (8.5%) had esophoria, 5 (3.85%) had exotropia, and 3 (2.3%) had esotropia. Cover tests were not performed in 4 (3.1%) students, as they were unable to fixate due to nystagmus or decreased vision. On ocular examination, 20 (15.3%) students had anterior segment abnormalities, including lid abnormality, conjunctivitis, Bitot’s spots, pterygium, corneal opacity, and lenticular opacity. Posterior segment or retinal abnormalities were found in four students with one having Usher syndrome. Color vision defects, nystagmus, and amblyopia were found in 8 (6.1%), 2 (1.5 %), and 1 (0.8%), respectively.
Conclusions: The findings of the present study reflect the need of periodic vision screenings in schools for the hearing impaired in Nepal. These children are at a high risk of vision impairment.
Effects of aiming lines and visual function on the golf putting alignment
You-Jin Kim, Young-Gap Jin, Bon-Yeop Koo, Jung-Un Jang, Ki-Choong Mah
Medical hypothesis, discovery & innovation in optometry, Vol. 2 No. 1 (2021), 16 June 2021 , Page 41-49
https://doi.org/10.51329/mehdioptometry124
Background: In golf, a player hits a ball with a club, aiming to transfer the ball successively into a series of hole cups in a course consisting of 18 (or fewer) holes. This study aimed to compare the impact of visual function and the presence and number of aiming lines on golf putting alignment between beginner and expert golfers.
Methods: In this prospective comparative study, 43 participants with a mean ± standard deviation (SD) of corrected distance binocular visual acuity of –0.07 ± 0.74 logarithm of the minimum angle of resolution, who knew their average golf scores, were divided into beginner and expert golfers. Six visual function tests were conducted to assess heterotropia, dominant eye, verification of current spectacles, static visual acuity, stereopsis, and fixation disparity. At the putting distances of 1.5 m and 3 m, alignment errors were measured five times each, using golf balls with 1 and 3 aiming line(s) and putters with 1 and 3 aiming line(s).
Results: The mean ± SD of age was 48.33 ± 10.07 years for study participants overall. The accuracy of ball alignment was not affected by the career or number of aiming lines, but the putter alignment was higher for the 3-lines putter than for the 1-line putter (P < 0.05). When the number and shape of the aiming line were the same for both the ball and putter, the aiming accuracy was found to be higher. In both stereopsis and fixation disparity, the combination of putting distance and a 3-lines ball showed negative values; all other combinations showed positive values, but no statistically significant correlation was detected (all P > 0.05).
Conclusions: The accuracy of golf ball alignment did not depend on the number of aiming lines and the golfer’s career. However, the predicted putting success rate and subjective satisfaction were increased when three-line golf balls and putters were used, as compared to when one-line golf balls and putters were used.
Winter 2020
Vol. 1 No. 3 (2020)
Anterior-segment optical coherence tomography for the detection and therapeutic monitoring of corneal disorders
Alejandro Rodriguez-Garcia , Andres Bustamante-Arias, Julio C. Hernandez-Camarena
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 3 (2020), 23 March 2021 , Page 105-107
https://doi.org/10.51329/mehdioptometry113
Background: Over recent years a revolutionary trend happened on imaging technologies to diagnose and monitor treatment of a varied group of ophthalmic pathologies. Recent reports have analyzed the microstructural changes of various ocular surface and corneal disorders, particularly ocular surface squamous neoplasia (OSSN) and keratoconus using anterior-segment optical coherence tomography (AS-OCT). Aim of this short communication is to elaborate on clinical applications AS-OCT for the detection and therapeutic monitoring of corneal disorders.
Methods: We performed an English literature search without a time limit and intending to identify articles related to the AS-OCT applications in the detection and therapeutic monitoring of corneal disorders. The most relevant articles were selected. practical points of selected papers and advantages and disadvantages of AS-OCT were retrieved from them and summarized.
Results: Many records reported the AS-OCT applications for diagnosing many ocular surface disorders, the microstructural changes of different inflammatory, infectious, degenerative, and dystrophic corneal disorders. Its applications in identifying disease activity and therapeutic monitoring of various corneal pathologies, including stromal edema associated with angle-closure glaucoma, Fuchs endothelial dystrophy, infectious keratitis, and bullous keratopathy, are promising. The percentage of diagnostic sensitivity, specificity, and accuracy of artificial intelligence methodologies applied to AS-OCT imaging analysis today has reached 94% to 100%. Moreover, AS-OCT is very useful for analyzing the extension of scar and leukoma depth for surgical planning of partial or total corneal transplantation.
Conclusions: There is a clear prospect for expanding application of corneal OCT imaging technology, a rapid, non-invasive, and now a promising lower-cost device, which is becoming an in-office standard-of-care tool for the assessment of different corneal and ocular surface pathologies.
Parkinson’s disease and convergence insufficiency: A mini-review
Mashael Al-Namaeh
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 3 (2020), 23 March 2021 , Page 108-111
https://doi.org/10.51329/mehdioptometry114
Background: A key manifestation of Parkinson disease (PD) is visual impairment. Cognitive impairment has been found to overlap with convergence insufficiency (CI) in patients with PD and is associated with significantly greater near point convergence (NPC) distance. Difficulty in reading and diplopia were the most common symptoms of CI in PD. The prevalence of CI is greater among patients with PD. Therefore, this study aimed to assess the relationship between PD and CI.
Methods: Studies that had included data on CI, NPC, or both were selected by searching PubMed/MEDLINE and clinicaltrails.gov, without any timeline or language limitation. The following terms were used in PubMed/MEDLINE search: Clinical Trials, Parkinson Disease, and Convergence Insufficiency. For clinical trials.gov database, the terms Parkinson Disease, Convergence Insufficiency, and Completed Studies were used. Only those studies with control subjects were included. PubMed/MEDLINE search yielded 1,563 articles, but no article was found in the clinical trails.gov search. Twelve articles met the inclusion criteria, among which nine articles were selected as they had data on CI or NPC distance (cm), and PD.
Results: Overall, there were 1,563 articles; among them, 12 articles met the inclusion criteria. Nine articles were selected based on their data concerning CI or NPC distance (cm) and PD. Relative to the control group, the PD group had high CI. In addition, PD group showed increase in NPC distance than the control group.
Conclusions: These data suggest that the patients with PD had an increased likelihood of developing CI visual symptoms, and increased NPC distance than healthy controls. These findings indicate that regular eye examination is very important for patients with PD.
Reliability of a Bahasa Melayu language version of the MOS 36-item short-form health survey (SF-36) in patients with low vision
Rokiah Omar, Siti Salwa Idris, Chiranjib Majumder, Chung Kah Meng, Nur Zakiah Mohd Saat, Zaleha Md Isa, Victor Feizal Knight
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 3 (2020), 23 March 2021 , Page 112-117
https://doi.org/10.51329/mehdioptometry115
Background: The MOS 36-Item Short-Form Health Survey (SF-36) Bahasa Melayu language version is widely used to determine the health outcomes in Malaysia. Low vision is a condition where vision cannot be restored and vision rehabilitation is required to overcome the challenges it imposes. The SF-36 Bahasa Melayu language version can be used to measure the health outcomes among low-vision patients. However, little information is available among low-vision patients. This study aimed to assess the reliability of the SF-36 Bahasa Melayu language version among low-vision patients.
Methods: Fifty low-vision patients aged 14 to 74 years (mean ± standard deviation: 44.58 ± 18.70 years) were randomly selected. All low-vision patients were interviewed twice by the same interviewer with a 2-weeks interval.
Results: The SF-36 Bahasa Melayu language version showed acceptable and good Cronbach alpha values of 0.68, 0.67, 0.76, 0.72, 0.73, 0.75, 0.72, 0.73 for physical function, role-physical, body pain, general health, vitality, social functioning, role-emotion, and mental health, respectively, in the first interview. The second interview also revealed similar Cronbach alpha values. The SF-36 Bahasa Melayu language version also showed a good repeatability between the first interview and the second interview, with Pearson correlation coefficients ranging from 0.6 to 0.9.
Conclusions: From this study, it can be concluded that the SF-36 Bahasa Melayu language version is reliable and repeatable. It is a useful tool to measure health outcomes among Malaysian low-vision patients. However, a future study of low-vision patients from the rural population and age groups representing the youth, working adults, and older individuals is necessary to obtain better outcomes of SF-36 in Bahasa Melayu language-based information on the health status of low-vision patients.
Combined implantation of toric and spherical intraocular lenses for low corneal astigmatism correction
Valeria Albano, Alessandra Sborgia, Carmela Palmisano, Giovanni Alessio
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 3 (2020), 23 March 2021 , Page 118-123
https://doi.org/10.51329/mehdioptometry116
Background: This study compared outcomes of combined toric versus spherical intraocular lens (IOL) implantation in patients with low corneal astigmatism.
Methods: In this retrospective contralateral study, patients with corneal astigmatism who received combined toric (FIL 611 T, Soleko, Rome, Italy) and spherical IOL (FIL 611 T, Soleko, Rome, Italy) implants were recruited. Eyes were examined preoperatively and then again 3 months postoperatively. Postoperatively, uncorrected distance visual acuity (UCDVA), residual astigmatism, and spherical equivalent (SE) were compared between the toric IOL-implanted eyes and the spherical IOL-implanted fellow eyes.
Results: Among the 46 included cases (age 69 ± 12.7 years [mean ± standard deviation]; range: 60-78 years), 86.9% of eyes (n = 40) in the toric IOL group had a postoperative refractive cylinder of less than or equal to 0.25 diopters (D), compared with 4.3% (n = 2) of eyes in the spherical IOL group. Both groups showed a statistically significant reduction in refractive cylinder and improvement in UCDVA after cataract surgery (both P = 0.01). Similarly, toric IOLs were superior (69.6%) to spherical lenses (2.2%) in obtaining a SE of less than or equal to 0.25 D.
Conclusions: To our knowledge, no previous study had sought to compare low-power toric and spherical IOLs in low corneal astigmatism in the same patient’s eyes. Our findings suggest that low-power toric IOLs may result in good refractive outcomes as compared with spherical IOLs implanted in the fellow eye of the same patient, although both result in significant UCDVA improvement. Well-designed clinical research studies with a longer follow-up and more participants are necessary to confirm these findings.
Changes in anterior segment parameters of normal subjects during accommodation using a Scheimpflug imaging system
Yadav Jitendra, De Tapas Kumar, Sah Sanjay Kumar, Sanyam Sandip Das
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 3 (2020), 23 March 2021 , Page 124-128
https://doi.org/10.51329/mehdioptometry117
Background: Accommodation changes ocular parameters, such as the anterior chamber volume (ACV), anterior chamber depth (ACD), anterior chamber angle (ACA), and pupil diameter (PD), which can reflect a risk of angle-closure glaucoma. Previous studies of changes in ocular anterior segment parameters, have used high diopters or maximum amplitude. Here, we focused on normal accommodation at a reading distance of 30-40 cm. The aim of this study was to assess changes in anterior segment parameters during a normal accommodative state, using a Scheimpflug imaging system.
Methods: In this cross-sectional study, 40 emmetrope subjects (mean ± SD of age: 22 ± 4.0 years) who met the inclusion criteria and provided informed consent were enrolled. Clinical history, refraction, amplitude of accommodation, slit lamp examination, Goldman applanation tonometry, and Pentacam investigations were performed on all subjects. Accommodative and non-accommodative targets were induced via the Pentacam. Two seconds were allowed for accommodation or relaxation prior to measurements in each eye.
Results: Eighty normal eyes were evaluated; a small but statistically significant change in ACV, ACA, and PD during accommodation (P < 0.01, < 0.01, and < 0.05, respectively) was observed. The ACD did not change substantially with accommodation (P = 0.29). The mean ± SD values of ACV, ACD, ACA, and PD before and after accommodation were 151.85 ± 24.04 mm3 and 145.38 ± 23.30 mm3, 2.87 ± 0.28 mm and 2.86 ± 0.27 mm, 35.06° ± 3.68° and 33.84° ± 3.72, and 3.46± 0.57 mm and 3.41 ± 0.53 mm, respectively.
Conclusions: Accommodation changes ocular parameters, such as ACV, ACA, and PD, in healthy young emmetropes. Interestingly, the ACD remains unaltered during accommodation. Nevertheless, although these changes were statistically significant, they were not clinically significant in our study.
Blue light-induced retinal damage: A brief review and a proposal for examining the hypothetical causal link between person digital device use and retinal injury
Michael R. Kozlowski
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 3 (2020), 23 March 2021 , Page 129-134
https://doi.org/10.51329/mehdioptometry118
Background: There is growing concern that the increased use of personal digital devices, which emit a high proportion of their light in the blue wavelengths, may have harmful effects on the retina. Extensive historical as well as current research demonstrates that exposure to high energy visible light (blue light) can damage the retina under certain circumstances. There are, however, no studies that directly address whether blue light at the intensities emitted by digital devices can potentially cause such harm. The present review aimed to examine whether blue light exposure from computers, tablets, and cell phones can, when used habitually over a prolonged period of time, be harmful to the retinal.
Methods: A search of the literature on blue light-induced retinal damage was performed using a number of scientific search engines, including BioOne Complete, Google Scholar, Paperity, PubMed, and ScienceOpen. Studies most significant for addressing the question of possible harmful effects of blue light emitted by personal digital devices were selected from this search and reviewed.
Results: The data from the selected studies were summarized and their limitations in addressing the question of whether the blue light from personal digital devices is capable of producing retinal damage were addressed. Based on these limitations, a practical experimental protocol for collecting the additional data needed was proposed. Data from pilot experiments are presented that indicate the practicality of this approach.
Conclusions: The currently available data on the effects of blue light on the retina are not sufficient to refute the hypothesis that the use of personal digital devices could, over a lifetime, produce retinal damage. Additional studies, such as those proposed in this article, are needed to resolve this issue.
Fall 2020
Vol. 1 No. 2 (2020)
Effects of ascorbic acid on chemical and thermal corneal burns: A comprehensive literature review
Mashael Al-Namaeh, Robert Andersson
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 2 (2020), 31 October 2020 , Page 44-51
https://doi.org/10.51329/mehdioptometry107
Background: Ascorbic acid has been suggested to be effective against chemical burns. It was first tested in rabbits before being implemented in human subjects. It was proven to be useful in treatments for different conditions, such as corneal chemical and thermal burns. Herein, we aimed to review the effects of ascorbic acid in the healing of chemical and thermal corneal burns.
Methods: We performed an electronic search of English literature in MEDLINE, clinicaltrials.gov, and Google Scholar, without time constraints. Articles were selected based on inclusion and exclusion criteria, using they keywords: Corneal Burn, AND Corneal Ulcer, AND Vitamin C. This yielded 17 English language articles focused on the effect of vitamin C on chemical or thermal corneal burn-induced ulcers.
Results: The 17 eligible studies that fulfilled the inclusion criteria included three retrospective, nonrandomized, comparative studies on human subjects and 14 in vivo, laboratory-based studies on rabbits (12 studies), rats (one study), as well as guinea-pigs (one study). Most studies showed benefits in using vitamin C as a prophylactic treatment to delay or stop corneal ulcer formation after chemical or thermal corneal burn.
Conclusions: Vitamin C is a very basic, inexpensive prescription and can be used to treat corneal ulcers following a variety of corneal burns. This review highlights the necessity for conducting randomized controlled trials to investigate the prophylactic role of vitamin C and to determine its minimum required dose for the management of corneal ulcers after different types of corneal burns.
Sutureless scleral-fixated intraocular lens: long-term outcomes
Vinaya Felcida, Anand Chawla, Dimitrios Kalogeropoulos, Ajai K Tyagi
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 2 (2020), 31 October 2020 , Page 52-56
https://doi.org/10.51329/mehdioptometry108
Background: The purpose of this study was to evaluate the long-term outcomes of sutureless scleral-fixated intraocular lens (SFIOL) implantation at a tertiary referral center.
Methods: This retrospective observational study included 50 eyes of 43 consecutive patients who underwent sutureless SFIOL implantation by a single surgeon from January 2009 to December 2015. Indications for surgery were aphakia, dislocated intraocular lens (IOL), complicated cataract surgery (posterior capsule rupture, zonular dialysis, dropped nucleus), iris-clipped IOL with corneal decompensation, and lens with poor capsular support. Indication for surgery, visual acuity, ocular history, ocular comorbidities, intraoperative and postoperative complications, and the need for further surgery were analyzed.
Results: The analysis conducted on 50 eyes from 43 patients with a mean ± standard deviation (SD) follow-up of 16.64 ± 9.34 months. Patients were 27 (63%) men and 16 (37%) women with a mean ± standard deviation (SD) age of 53.36 ± 22.45 years (range 8-90 years). Final visual acuity was 6/18 or better in 39 eyes. SFIOL was stable and well centered in 48 eyes. SFIOL dislocation was noted in 2 eyes, retinal detachment in 1 eye, and worsening of diabetic cystoid macular edema in 1 eye. Two patients with pre-existing corneal decompensation from complicated cataract surgery had worsening of their condition
Conclusions: Sutureless SFIOL could be considered as a long-term option for the management of aphakia, dislocated IOL, and lens with poor capsular support. However, future studies with more subjects, longer follow-ups, and robust study design are needed to confirm the results of the present study.
Surgical versus optical treatment for anisometropia in adults: A randomized controlled trial
Mohammed Iqbal, Ali Mahmoud, Marcos Zarif, Ahmad Gad
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 2 (2020), 31 October 2020 , Page 57-66
https://doi.org/10.51329/mehdioptometry109
Background: We evaluated and compared outcomes of laser-assisted in situ keratomileusis (LASIK) versus optical spectacle correction for the treatment of anisometropia in adult patients.
Methods: This prospective, randomized controlled clinical trial included 50 eyes of 50 patients. We randomly allocated participants to Group A (25 eyes with anisometropia assigned to LASIK treatment) and Group B (25 eyes with anisometropia assigned to optical spectacle correction). All patients underwent preoperative and postoperative visual acuity, subjective and cycloplegic refraction, fundus, slit-lamp, and corneal topography examinations.
Results: In Group A, at 1-month postoperatively, there were statistically significant differences in uncorrected distance visual acuity, corrected distance visual acuity, refractive sphere, cylinder, and spherical equivalent (SE) as compared to baseline. At 3-months postoperatively in Group A, SE showed good stability within ± 0.50 diopter (D) in 22 eyes (88%) and within ± 0.75 D in 23 eyes (92%), while two eyes had an SE beyond 1.00 D emmetropia. Five eyes had amblyopia with minimal improvement in two eyes in Group A after LASIK, and no improvement in three eyes treated with spectacles in Group B. Two amblyopic eyes had developed ocular deviations by the end of the study that referred to the strabismus unit.
Conclusions: Our outcomes revealed that LASIK was more effective and advantageous than spectacles in the treatment of different types of anisometropia in adults. However, future randomized trials should focus on optical versus surgical treatment of anisometropia and anisometropic amblyopia in both pediatric and adult patients, to verify these conclusions before generalizing this treatment modality.
Overview of pharmacological treatments for presbyopia
Betina Orman, Giovanna Benozzi
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 2 (2020), 31 October 2020 , Page 67-77
https://doi.org/10.51329/mehdioptometry110
Background: Presbyopia is the normal progressive waning of accommodation with loss of the visual ability to focus on objects residing at different distances. Presbyopia exacts a cost in quality of life and professional efficiency of many people over 40 years of age. Presbyopia is likely to be 1 of the main pressing visual concerns of the 21st century, given that life expectancy is increasing, resulting in an aging population. This review aimed to address the 3 strategies of the pharmacological treatment for presbyopia.
Methods: A review on PubMed/MEDLINE, Google Scholar, and Clinicaltrials.gov was performed to investigate the English literature on pharmacological treatment for presbyopia from beginning-of-year 2012 to September 30, 2020.
Results: In addition to the treatment of presbyopia with glasses or contact lenses, new surgical strategies have been developed, some of which have been successful. However, during the last decade, a new, promising, non-invasive option for treating presbyopia has emerged: the pharmacological approach. Many researchers have developed 3 different lines of investigation from different assumptions, on a pharmacological basis. The first consisted of producing miosis, to take advantage of a pharmacologically induced pinhole effect, increasing depth-of-focus, and thus improving uncorrected near visual acuity. The second aimed to rehabilitate accommodation binocularly to enable good vision at all distances. Finally, the third approach attempted to rehabilitate lost elasticity in the human crystalline lens.
Conclusions: None of the 3 discussed pharmacological strategies for treating presbyopia, prescribed globally, but patients of restoring accommodation strategy can adhere locally, where they are sold so far as master prescriptions.
Five generations of intraocular lens power calculation formulas: A review
Georgios Tsiropoulos , Eleftherios Loukovitis, Spyridon N Koronis, Georgios Sidiropoulos, Eleni Tsotridou, Georgios Anogeianakis
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 2 (2020), 31 October 2020 , Page 78-99
https://doi.org/10.51329/mehdioptometry111
Background: The effectiveness of cataract surgery depends on preoperative biometric data, including the axial length (AL), keratometric value (K), anterior chamber depth (ACD), and the accuracy of the intraocular lens power (IOLp) calculation. Five generations of IOLp calculation formulas have been developed. This review summarizes these formulas and focuses on the characteristics, advantages, and disadvantages of each. Moreover, it compares the results of several formulas used in patients with specific characteristics.
Methods: The authors searched PubMed and Google Scholar, using keyword combinations including IOLp, formulas, AL, ACD, K, and diopters (D). Two hundred recent articles that referred to IOLp calculation formulas and their effectiveness when used preoperatively in cataract surgery were retrieved and analyzed.
Results: Each generation has advantages and disadvantages for individual patients, and the selection of the most appropriate IOL differs due to different ALs of patients. The shorter or longer the eye is, the less accurate some formulas become. Formulas such as SRK-T, Holladay, SRK-II, Hoffer, and Binkhorst II seem to have comparable efficacy. However, studies have indicated that Hoffer is superior for short eyes. In contrast, SRK/T appears to be slightly more superior for long eyes. The fifth-generation formulas also appear to be very promising.
Conclusions: Based on the available literature, there is no gold standard as yet that can be used for all patients. Instead, each patient should be managed individually depending on their particular eye characteristics.
Higher-order aberrations following wavefront-guided photorefractive keratectomy and laser in situ keratomileusis
Esra Vural, Deniz Kilic, Ayse Cicek, M. Rasit Sirem, Necati Duru, Mustafa Atas
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 2 (2020), 31 October 2020 , Page 100-104
https://doi.org/10.51329/mehdioptometry112
Background: We aimed to evaluate higher-order aberrations (HOAs) following wavefront-guided photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) in patients with myopia and myopic astigmatism.
Methods: This retrospective observational case-control study included patients who underwent wavefront-guided PRK (40 eyes of 20 patients) or LASIK (40 eyes of 20 patients) between August 2018 and November 2018 at the refractive surgery unit of Kayseri City Hospital Eye Clinic, Turkey. The corrected distance visual acuity (CDVA), manifest refraction, corneal topography, and HOAs were evaluated preoperatively and 3 months postoperatively in all patients.
Results: The mean age ± standard deviation (SD) was 27.13 ± 5.54 years and 29.10 ± 4.38 years in the PRK and LASIK groups, respectively (P = 0.06). Both groups had a mean CDVA of 1.00. The mean ± SD of spherical and spherical equivalent values was -2.09 ± 1.56 diopter (D) and -3.03 ± 1.72 D in the PRK group and -2.23 ± 1.69 D and -3.35 ± 1.71 D in the LASIK group, respectively (P = 0.58). When the preoperative and postoperative HOAs and root mean square (RMS) values (for a 6-mm pupil diameter) were compared in the PRK group, a significant difference was found in vertical coma and total RMS values (P = 0.003 and P less than 0.001, respectively); in the LASIK group, there was a significant difference in preoperative and postoperative vertical coma and total RMS values (P = 0.0.001 and P less than 0.001, respectively). There was no significant difference in preoperative and postoperative vertical coma values between the two groups (P = 0.735 and P = 0.583, respectively).
Conclusions: In terms of HOAs, total RMS values decreased significantly and vertical coma values increased significantly at 3 months postoperatively in both PRK and LASIK groups. However, there were no differences between the two groups.
Summer 2020
Vol. 1 No. 1 (2020)
Ocular manifestations of Parkinson disease
Mashael Al-Namaeh
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 1 (2020), 31 August 2020 , Page 1-10
https://doi.org/10.51329/mehdioptometry101
Background: Parkinson’s disease (PD) is the second most common neurodegenerative disorder. We aimed to review both the disease and the drug-related ocular manifestations of PD.
Methods: In this manuscript, we have reviewed and summarized existing literature on the ocular manifestations and drug-related complications of PD. We have also discussed the use of current noninvasive imaging techniques, such as optical coherence tomography (OCT), for the early diagnosis and monitoring of PD.
Results: Impaired color vision, reduced stereopsis, reduced contrast sensitivity, pupillary abnormalities, eye movement disorders, convergence insufficiency, dry eye syndrome, glaucoma, visual dysfunctions, retinal abnormalities, and drug-related side effects were among the listed ocular manifestations of PD. There is a large knowledge gap regarding the type of glaucoma affecting PD patients-whether it is open-angle or other types. Further case studies and long-term follow-ups during PD progression are necessary to fill this gap. Patient compliance with follow-up visits for more visual field tests and OCT during PD progression may become problematic when dementia and cognitive impairment occur.
Conclusions: There is a general need for clinicians to perform further tests and more visual examinations to rule out ocular manifestations. Furthermore, additional clinical trials are needed to further evaluate the use of different types of OCT findings as biomarkers of PD progression. This would aid in early diagnosis and in delaying disease progression, if treated promptly.
Normative value of photostress recovery time among various age groups in southern India
Bhandari Bishwash, De Tapas Kumar, Sah Sanjay Kumar , Sanyam Sandip Das
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 1 (2020), 31 August 2020 , Page 11-17
https://doi.org/10.51329/mehdioptometry102
Background: To determine the normative data and reference value for photostress recovery time (PSRT) following exposure of the macula to light, in various age groups within the Indian population.
Methods: Cross-sectional observational study performed from November 2015 to July 2016 in the Bangalore district of Karnataka state in India. We examined a total of 1,282 eyes of 641 participants and included those with corrected distance visual acuity (CDVA) scoes lower than or equal to 0.4 Logarithm of the Minimum Angle of Resolution (LogMAR). We performed the photostress procedure under standard conditions using the same approach.
Results: The mean ± standard deviation (SD) of the age of participants age was 32.04 ± 15.80, with an age range of 8 to 70 years. The PSRT in participants below 16 years and above 45 years of age were significantly different compared to the 16-25-year-old age group (P < 0.0001 for both). The PSRT values were significantly different between males and females in the reproductive age group (16 to 45 years old) (P < 0.0001), but not in the other age groups.
Conclusions: The PSRT values were significantly different in children and older patients compared to the 16 to 25 years age group. We found that as age increased, PSRT increased significantly.
Early retinal degeneration in Huntington’s disease based on optical coherence tomography: A case-control study
Sergey Svetozarskiy , Svetlana Kopishinskaya, Igor Smetankin
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 1 (2020), 31 August 2020 , Page 18-24
https://doi.org/10.51329/mehdioptometry103
Background: The purpose of this study was to analyze optical coherence tomography (OCT) parameters of the choroid and retina in subjects with pre-manifest and manifest Huntington’s disease (HD).
Methods: In this case-control study, the retinal parameters of patients with genetically confirmed HD and healthy controls were evaluated using spectral-domain optical coherence tomography (SD-OCT). Genetic and neurological assessments were performed besides a thorough ophthalmological examination. Contrast Sensitivity (CS) logarithm was evaluated using the Freiburg Vision Test. The association between OCT parameters and clinical and genetic characteristics was studied.
Results: A total of 91 subjects, including 60 HD subjects (60 eyes) and 31 control subjects (31 eyes) were eligible according to the inclusion and exclusion criteria. The range of the CAG (cytosine-adenine-guanine) repeat expansion size was 38-56 repeats, the mean ± standard deviation (SD) of the Unified HD Rating Scale (UHDRS) motor scores was 36.3 ±29.7, and disease duration was 13.7 ±7.2 years in HD subjects. Compared to the control group, significant decreases in the mean ganglion cell complex thickness and mean, temporal, superior, inferior, and nasal retinal nerve fiber layer (RNFL) thickness in HD subjects was revealed in OCT examination (P-values < 0.001, < 0.001, < 0.001, 0.023, 0.007 and 0.014, respectively). An inverse correlation between the disease duration and the mean RNFL thickness (r =- 0.470, P = 0.002) was found.
Conclusions: Localization of retinal thickness loss shows a specific pattern of retinal neurodegeneration in HD, similar to Parkinson disease and mitochondrial diseases. The association with the disease duration confirms the progressive nature of these changes.
Use of automatic refractometer infrared images to screen pigment dispersion syndrome: A cross-sectional observational study from a preliminary hypothesis
Paolo Brusini, Veronica Papa
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 1 (2020), 31 August 2020 , Page 25-28
https://doi.org/10.51329/mehdioptometry104
Background: This study was performed to evaluate the use of anterior segment images, obtained with an automatic refractometer, to identify early defects of the iris pigment epithelium in patients with pigment dispersion syndrome (PDS) or pigmentary glaucoma (PG) without observable alterations at the slit lamp.
Methods: In this cross-sectional observational study, carried out from January 2018 to December 2019, in Policlinico Citta di Udine Health Center, Udine, Italy, we observed anterior segment infrared images of 1700 subjects who were undergoing routine ophthalmological examination using an automatic refractometer. We selected infrared images of subjects who fulfilled the inclusion and exclusion criteria and looked for a focal defect in the iris pigment epithelium.
Results: Twenty patients with focal iris pigment epithelial defect were identified and none of them showed evident signs of PDS. After the necessary explanations, they agreed to have further examinations to verify the possibility of PDS. An in-depth evaluation of ocular structures, including gonioscopy, demonstrated the presence of PDS in all subjects with iris defects.
Conclusions: The use of infrared images obtained by an automatic refractometer could provide early and easy identification of PDS in crowded ophthalmology clinics or mass screening programs; yet, more well-designed studies are necessary to confirm these preliminary findings and prove this proposed screening tool.
Role of intestinal microbiome in the pathogenesis of age-related macular degeneration
Dimitrios Kalogeropoulos, Konstantinos Katsikatsos, Konstantinos Dallas, Soon Wai Ch’ng, Ioannis Asproudis, Maria Stefaniotou, Chris Kalogeropoulos
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 1 (2020), 31 August 2020 , Page 29-36
https://doi.org/10.51329/mehdioptometry105
Background: The microbiome is strongly linked to many extra-intestinal disorders. Gut commensal microbiota, in particular, plays an active role in human immune and intestinal homeostasis. Complex interactions of the microbiota with host genetics and other underlying factors lead to intestinal dysbiosis, which is thought to be linked to ocular inflammatory diseases. Thus, the aim of this review is to analyze the role of intestinal microbiome in age-related macular degeneration (AMD).
Methods: A thorough literature search was performed using PubMed/MEDLINE, limited to English language publications, from January 2004 to March 2020. An additional search was made employing Google Scholar to complete the collected data as per the above-mentioned time-line and language limitations. The main keywords used included age-related macular degeneration, microbiome, dysbiosis, autoimmunity, gut microbiota, epigenetics, immune-mediated inflammatory diseases, and gut-retina axis.
Results: Recent studies have proposed the role of intestinal microbiota in the pathogenesis of AMD. Changes in the microbiome have been shown to trigger several ocular inflammatory processes. There is increasing evidence demonstrating that intestinal microbial imbalance may play an important role in the pathogenesis of AMD.
Conclusions: This review summarizes how alterations in the intestinal microbiota can be associated with the pathogenesis of AMD and how new therapeutic modalities can be designed to target this microbiome to limit the severe nature of this disease. Future advances in microbiome research may unveil a new era in understanding and managing AMD.
Two-year successful results of femto-LASIK in steep and opacified corneas
Amr Mounir, Emad Latif Matthias, Islam Awny
Medical hypothesis, discovery & innovation in optometry, Vol. 1 No. 1 (2020), 31 August 2020 , Page 37-43
https://doi.org/10.51329/mehdioptometry106
Background: Flap creation is the most critical step of laser in situ keratomileusis (LASIK). The introduction of the femtosecond laser with its uniform flaps, which enhance the accuracy of LASIK, has decreased the risk of flap-related complications like buttonholes and incomplete flaps. We recommended femtosecond laser-assisted LASIK (FS-LASIK) in the presence of superficial corneal opacities.
Case Presentation: We report a case of a 31-year-old female who reported to the Cornea clinic of the Sohag Center for LASIK and Corneal Surgeries, Sohag, Egypt, complaining of bilateral decreased vision due to refractive error. The uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were 0.01 and 0.7 with a refractive correction of -3.50Ds/ -3.00Dc x 172° in the right eye and 0.01 and 0.6 with a refractive correction of -1.75 Ds/-6.00Dc x164° in the left eye, respectively. Slit-lamp examination of the anterior segment showed bilateral superior vascularized corneal scars and a linear superior conjunctival scar suggestive of old trachoma. Corneal tomographic imaging with a Scheimpflug based tomography device (Oculus Inc., Wetzlar, Germany) revealed a symmetrical bow tie with a very steep cornea without other ectatic changes. The patient underwent bilateral FS-LASIK with an excimer laser. No intraoperative complications occurred. She was followed up for two years with serial corneal topographies and stable post-LASIK results and visual outcomes.
Conclusions: FS-LASIK, in the presence of superficial corneal opacities, was safe and effective and induced no complications with special precautions. However, these findings are yet to be confirmed using well-designed clinical studies with larger samples and longer follow-ups.
IVORC, Collaboration on Innovations 