Vision-related quality of life in patients with retinal vein occlusion.

PURPOSE: This study aims to assess the vision-related quality of life in patients with retinal vein occlusion (RVO) among those referred to Labbafinejad Medical Center and Imam Hossein Hospital between 2019 and 2021. METHODS: This comparative study included 37 eligible patients diagnosed with various types of RVO, with an average age of 61 ± 9. To ensure data validity, we included 74 age- and sex-matched healthy individuals. Only cases with a definitive diagnosis of RVO, confirmed by two retina specialists (ND and RN), were included. We assessed the vision-related quality of life of our participants using the National Eye Institute Visual Functioning Questionnaire-25 (NEI-VFQ-25). All participants underwent interviews. RESULTS: In our study, we examined the vision-related quality of life in different subgroups of RVO patients. Overall, RVO patients had a significantly lower total VRQoL score compared to healthy individuals (P < 0.001), except in the subscale analysis of specific factors such as ocular pain, color vision, and driving, where no statistically significant difference was observed. A statistically significant difference was found in the comparison of subgroups, indicating lower VRQoL in central retinal vein occlusion (CRVO) patients (P = 0.010). Furthermore, a significant correlation was observed between lower VRQoL and decreased vision (P = 0.009) as well as longer disease duration (P = 0.011). CONCLUSION: Retinal vein occlusion can significantly reduce vision-related quality of life, particularly in more severe cases.

Comparison of epidemiologic factors and eye manifestations of twin children with controls.

PURPOSE: The present study was aimed to compare the epidemiological and ocular findings of twin children in comparison with non- twin age matched individuals as their control. METHODS: In this cross sectional study, a total of 90 twins (180 cases) were compared with 182 non- twin matched children. All the study participants were examined by a comprehensive ophthalmic examination including measurement of the best corrected visual acuity (BCVA), cycloplegic refraction, ocular deviation, strabismus as well as the anterior and posterior ophthalmic examinations. Demographic information of children were collected by using an organized questionnaire. Monozygotic twins were considered if there were similarity of their phenotypic characteristics and gender, otherwise the twins were considered as dizygotic. RESULTS: The mirror- image twins (MIT) was defined according to the laterality of symmetrical ocular characteristics of twins. In this study, the mean age of the study participants was 7.08±4.42 and 7.58±3.99 years in twins and non-twins groups, respectively (P=0.253). Among the twins, 27 (30%) were monozygotic. Refractive form of MIT was seen in 5 twins (2.8%). The spherical refractive error was more hyperopic in twins compared to non- twins (P=0.041). BCVA in the twin group (0.07±0.16LogMAR) was significantly worse than non-twins (0.03±0.08LogMAR, P < 0.001) and higher percentage of them were amblyopic (37.2% versus 10.4%, P=0.005). Twin and controls had strabismus in 17.2% and 1.6%, respectively (P < 0.001). Regarding the comparison between mono- and dizygotic twins, more significant percentage of monozygotic twins had amblyopia (P=0.004) and strabismus (P=0.047). Multivariate analysis showed significant correlation among low gestational age and female gender, low birth weight and seizure. CONCLUSION: Female sex, less gestational age, low birth weight, amblyopia and strabismus were significantly higher in twins. Therefore, it is important to check their refractive error, amblyopia and strabismus to prevent their further complications.

Indications and outcomes of intraocular Lens Exchange among pseudophakic eyes in a Tertiary Referral Center.

PURPOSE: To determine the indications and surgical outcomes of intraocular lens (IOL) exchange in pseudophakic patients at Labbafinejad Tertiary Referral Center between 2014 and 2019. METHODS: In this retrospective interventional case series, the medical records of 193 patients with a history of IOL exchange were reviewed. Preoperative data, including clinical characteristics, indications of the first and second IOL implantation, intra- and postoperative complications due to IOL exchange, and the pre-and postoperative refractive error and best-corrected visual acuity (BCVA) were considered the outcome measures in this study. All postoperative data were analyzed at least six months after follow-up. RESULTS: The mean age of our participants was 59.13 ± 20.97 years old at the time of the IOL exchange, with a male percentage of 63.2%. The mean follow-up after the IOL exchange was 15.72 ± 16.28 months. The main indications of IOL exchange were IOL decentration (50.3%), corneal decompensation (30.6%), and residual refractive errors (8.3%). 57.10% of patients with the postoperative spherical equivalent at -2.00 diopter (D) to + 2.00D. The mean best-corrected visual acuity was 0.82 ± 0.76 LogMAR before the IOL exchange and was improved to 0.73 ± 0.79 LogMAR after the surgery. Corneal decompensation (6.2%), glaucoma (4.7%), retinal detachment (4.1%), cystoid macular edema (2.1%), and uveitis (1%) were found as the postoperative complications. There was only one case with suprachoroidal hemorrhage during IOL exchange. CONCLUSIONS: IOL decentration followed by corneal decompensation was the most common indication of IOL exchange. After IOL exchange, the most complications during follow-up were corneal decompensation, glaucoma, retinal detachment, and cystoid macular edema.

The effect of topical ketorolac tromethamine on macular thickening after phacoemulsification in diabetic patients.

BACKGROUND: To determine the effect of ketorolac tromethamine 0.5% in preventing post-phacoemulsification macular thickening. This randomized clinical trial. patients randomized 1:1 to receive either topical ketorolac three times a day or a placebo. METHODS: A total of 101 eyes of 101 diabetic patients who were scheduled for phacoemulsification and had normal macular contour and thickness enrolled consecutively. The topical ketorolac and placebo were prescribed on the day before surgery and continued up to 4 weeks after surgery. Patients with proliferative diabetic retinopathy, a history of intravitreal injection in less than three months, a history of macular photocoagulation in less than 6 months, and any other concomitant ocular pathologies were excluded. Central macular thickness (CMT) and best corrected visual acuity (BCVA) was recorded in the follow-ups of 6, 12, and 24 weeks after the surgery and compared with the controls. RESULTS: 49 eyes in the case group and 52 eyes in the control group were analyzed. Mean BCVA was significantly improved in both groups at all follow-ups (P < 0.001 for all). There was no statistically significant difference regarding the BCVA in different time points except week 12 (P = 0.028) among the study group. In the case and control groups, CMT was increased at all follow-ups (P < 0.05). There was no statistically significant difference when comparing the two groups regarding the mean of CMT at any time point postoperatively (P > 0.05 for all). CONCLUSION: Based on our findings, topical ketorolac tromethamine 0.5% is not effective in the prevention of post-phacoemulsification macular thickening in diabetic patients. TRAIL REGISTRATION: The study protocol was registered into www. CLINICALTRIAL: gov with the RCT registration number NCT03551808. (2018/06/11 ) CLINICAL TRIAL REGISTRATION NUMBER: NCT03551808.

Development and evaluation of a customized checklist to assess the quality control of disease registry systems of Tehran, the capital of Iran in 2021.

BACKGROUND: Clinical registries facilitate medical research by providing 'real data'. In the past decade, an increasing number of disease registry systems (DRS) have been initiated in Iran. Here, we assessed the quality control (QC) of the data recorded in the DRS established by Shahid Beheshti University of Medical Sciences in Tehran, the capital city of Iran, in 2021. METHODS: The present study was conducted in two consecutive qualitative and quantitative phases and employed a mixed-method design. A checklist containing 23 questions was developed based on a consensus reached following several panel group discussions, whose face content and construct validities were confirmed. Cronbach's alpha was calculated to verify the tool's internal consistency. Overall, the QC of 49 DRS was assessed in six dimensions, including completeness, timeliness, accessibility, validity, comparability, and interpretability. The seventy percent of the mean score was considered a cut-point for desirable domains. RESULTS: The total content validity index (CVI) was obtained as 0.79, which is a reasonable level. Cronbach's alpha coefficients obtained showed acceptable internal consistency for all of the six QC domains. The data recorded in the registries included different aspects of diagnosis/treatment (81.6%) and treatment quality requirements outcomes (12.2%). According to the acceptable quality cut-point, out of 49 evaluated registries, 48(98%), 46(94%), 41(84%), and 38(77.5%), fulfilled desirable quality scores in terms of interpretability, accessibility, completeness, and comparability, however, 36(73.5%) and 32(65.3%) of registries obtained the quality requirement for timeliness and validity, respectively. CONCLUSION: The checklist developed here, containing customized questions to assess six QC domains of DRSs, provided a valid and reliable tool that could be considered as a proof-of-concept for future investigations. The clinical data available in the studied DRSs fulfilled desirable levels in terms of interpretability, accessibility, comparability, and completeness; however, timeliness and validity of these registries needed to be improved.

Prevalence of cataract and its contributing factors in Iranian elderly population: the Gilan eye study.

PURPOSE: To report the prevalence and the associated factors leading to cataract among the Iranian population living in Gilan Province, Iran. METHODS: This population-based cross-sectional study was performed from June to November 2014 on 2,975 residents aged ≥ 50 years old living in urban and rural regions of the Gilan Province in Iran. A representative sample of residents in the province was recruited into the study through door-to-door visiting, and baseline data were collected by questionnaire. All participants were referred to the medical center for comprehensive ophthalmic examination, laboratory tests, and blood pressure measurement. RESULTS: Among the population, 2,588 (86.99%) subjects were eligible to be included in this study, categorized either into the cataract or the non-cataract group. The mean age of participants was 62.59 ± 8.92 years, and 57.5% were female. Higher prevalence of cataract was found in individuals of older ages (odds ratio (OR) = 1.13; 95% confidence interval (CI) = 1.10 to 1.16; P < 0.001) and a history of previous ocular surgery (OR = 5.78; 95% CI = 2.28 to 14.63; P < 0.001). At the same time, a lower prevalence of cataract was seen in patients exposed to sunlight for more than 4 h per day (OR = 0.49; 95% CI = 0.32 to 0.73; P = 0.001). CONCLUSION: Cataract affects 50.50% of the study population, especially those over 80. The mildest form of cataract, grade zero, is the most common. Surgery for cataract has good outcomes. The risk of cataract is higher for those older or who have had eye surgeries. People not affected by cataract tend to be exposed to more sunlight.

Unraveling the genetic complexities of combined retinal dystrophy and hearing impairment.

Usher syndrome, the most prevalent cause of combined hereditary vision and hearing impairment, is clinically and genetically heterogeneous. Moreover, several conditions with phenotypes overlapping Usher syndrome have been described. This makes the molecular diagnosis of hereditary deaf-blindness challenging. Here, we performed exome sequencing and analysis on 7 Mexican and 52 Iranian probands with combined retinal degeneration and hearing impairment (without intellectual disability). Clinical assessment involved ophthalmological examination and hearing loss questionnaire. Usher syndrome, most frequently due to biallelic variants in MYO7A (USH1B in 16 probands), USH2A (17 probands), and ADGRV1 (USH2C in 7 probands), was diagnosed in 44 of 59 (75%) unrelated probands. Almost half of the identified variants were novel. Nine of 59 (15%) probands displayed other genetic entities with dual sensory impairment, including Alström syndrome (3 patients), cone-rod dystrophy and hearing loss 1 (2 probands), and Heimler syndrome (1 patient). Unexpected findings included one proband each with Scheie syndrome, coenzyme Q10 deficiency, and pseudoxanthoma elasticum. In four probands, including three Usher cases, dual sensory impairment was either modified/aggravated or caused by variants in distinct genes associated with retinal degeneration and/or hearing loss. The overall diagnostic yield of whole exome analysis in our deaf-blind cohort was 92%. Two (3%) probands were partially solved and only 3 (5%) remained without any molecular diagnosis. In many cases, the molecular diagnosis is important to guide genetic counseling, to support prognostic outcomes and decisions with currently available and evolving treatment modalities.

New criteria for evaluation of electroretinogram in patients with retinitis pigmentosa.

BACKGROUND: Electroretinogram (ERG) plays an essential role in the diagnosis of retinal disease. Choosing appropriate methods could extract valuable information from ERG. In this study, a new criterion based on time-frequency domain analysis was proposed to investigate the retina in retinitis pigmentosa (RP) patients. MATERIALS AND METHODS: The total number of 16 eyes from eight RP patients and 20 eyes from age-matched healthy subjects were assessed. The signals included photopic and scotopic ERGs. Continuous wavelet transform was applied to ERGs. Dominant frequencies were extracted, and the contours related to these dominant frequencies were selected. As a new criterion, the areas related to dominant frequency contours were considered a feature to differentiate the RP and normal groups. To better evaluate the proposed criterion results, the time-domain analysis characteristics of ERG were also considered. RESULTS: The results showed an increase in implicit time and reduced amplitude in RP patients (P < 0.05). A significant decrease of dominant frequencies and increasing their occurrence time were seen in ERG of RP patients. Also, in RP patients, the third dominant frequency was disappeared from the three main frequencies observed in photopic ERGs of normal subjects. The area criterion showed a significant decrease in RP groups (P < 0.05). CONCLUSION: RP can cause changes in the time and time-frequency components of the ERG. The area index could represent a new view of the characteristics of the ERG in the time-frequency domain. This criterion can help the ophthalmologist to have a better evaluation of retinal disease.

Comparison of medial rectus resection and plication in exotropic patients.

PURPOSE: To compare the surgical outcomes of the plication technique with the resection method to treat exotropic patients. METHODS: In this prospective randomized clinical trial, a total of 52 exotropic patients (27 females and 25 males) who were candidates for medial rectus resection were randomly classified into the plication (n = 24) and resection (n = 28) groups. Comprehensive ophthalmic examination included cyclorefraction, assessment of the best corrected visual acuity (BCVA), evaluation of the extraocular muscle, ocular deviation measurement and stereopsis measured using a Titmus test. Ocular anterior and posterior segments were examined using slit-lamp and indirect ophthalmoscopy. Patients were randomly divided to medial rectus plication and medial rectus resection groups. The plication technique was the same as for resection, but in the last step the muscle was folded. Examinations were repeated at the 1- and 3-day as well as 1-, 2-, 3- and 6-month follow-ups. If the postoperative ocular deviation was in the range of 5 PD esotropia to 10 PD exotropia, it was considered a successful surgical outcome. RESULTS: Results show that there was no statistically significant difference between the two groups regarding near and far deviations (PN = 0.298, PF = 0.103), surgical dose response (P = 0.904) and postoperative success rate (plication, 87% and resection, 89.3%, P > 0.99). Reoperation was needed in 13% and 10.7% of the plication and resection groups, respectively (P > 0.05). CONCLUSIONS: Medial rectus plication is an effective and appropriate alternative option for medial rectus resection in exotropic patients.

Fundus torsion following inferior oblique muscle weakening.

PURPOSE: To determine the postoperative fundus torsion following surgical inferior oblique (IO) weakening in patients with inferior oblique overaction (IOOA). METHODS: In this interventional case series, 37 patients with IOOA ≥ +1 and reliable preoperative fundus photographs were included. IO weakening was accomplished through myectomy or anterior transposition. Fundus photography was repeated at 3 months' follow-up. The primary outcome was change of disk foveal angle (DFA), measured as the angle between the line connecting the center of the fovea and optic disk and horizontal. Success or normal fundus torsion was defined as a postoperative angle of 0° to 8° of extorsion. Residual extorsion was defined as postoperative extorsion of > 8°. Postoperative intorsion was defined as any amount of induced intorsion. RESULTS: Mean age of patients (56% females) was 6.46 ± 6.79 years. At follow-up at least 3 months after surgery, the mean change of DFA was 7.79 ± 6.24° of reduction of extorsion after IO myectomy (P < 0.001) and 6.05 ± 6.07° after IO anterior transposition (P = 0.005). Normal fundus torsion was achieved in 50% of patients after myectomy and 36.4% of patients after anterior transposition. Residual extorsion was observed in 49% of patients; induced intorsion in 5%. CONCLUSIONS: Using objective measurement of fundus photographs, fundus extorsion was decreased in 94.7% of patients after myectomy or anterior transposition.

Polymeric Propranolol Nanoparticles for Intraocular Delivery: Formulation, Characterization, and Vitreous Pharmacokinetics.

Purpose: Recent studies have reported the promising effect of intravitreal propranolol on retinal neovascularization. However, rapid clearance and short half-life of the drug in the vitreous are the main drawbacks of this therapeutic approach. This study investigates the extension of the residence time of propranolol in the vitreous by polymeric nanoparticles (NPs) with the prospect of improving choroidal neovascularization treatment. Methods: The poly (lactic-co-glycolic) acid (PLGA) NPs were fabricated by a modified double emulsion solvent evaporation method and the obtained NPs were characterized for their size, poly dispersity index (PDI), and surface image. The in vitro release, cell cytotoxicity, and uptake of NPs were also evaluated. To investigate the effect of the vitreous pharmacokinetic drug loaded NPs versus that of the free propranolol, they were intravitreally injected into the rabbits' eyes and the drug vitreous concentrations in defined intervals were analyzed by high performance liquid chromatography (HPLC). Results: The spherical NPs with about 230 nm size, and almost 10% drug loading were obtained. Based on the 3-(4, 5-Dimethylthiazol-2-Yl)-2, 5-Diphenyltetrazolium Bromide (MTT) outcomes, 30 µg/ml of propranolol was considered as the guide dosage in the intravitreal injection. Confocal microscopy images verified the presence of labeled NPs in the posterior segment after five days of receiving the injection. In vivo assay revealed that the vanishing rate of propranolol in rabbits treated with propranolol NPs was reduced at twice the rate as compared to that of the vanishing rate experienced with only the free drug. Conclusion: PLGA NPs can prolong the existence of propranolol in both vitreous and posterior ocular tissues, and thus, may provide an effective approach in treatment of posterior segment neovascularization.

Prevalence of refractive errors in population aged 50 years and over: The Gilan eye study.

PURPOSE: To describe the prevalence of refractive error (RE) and its association with other environmental and health factors among population aged ≥50 years who lived in Gilan, Iran in 2014. METHODS: In this population-based cross-sectional study, 3281 individuals aged ≥50 years living in Gilan for at least 6 months were enrolled. The prevalence of different types of REs including myopia (spherical equivalent (SE)≤-0.50D), high myopia (SE ≤ -6.00D), hyperopia (SE≥ + 0.50D), high hyperopia (SE≥ + 3.00D), astigmatism (cylinder < -0.50D) and high astigmatism (cylinder < -2.25D) were determined. Anisometropia was defined as the SE difference of ≥1.00D between the two eyes. Associated factors including age, body mass index (BMI) and education were also studied. RESULTS: 2587 eligible individuals (58% female subjects) with the mean age of 62.6 ± 8.8 years participated (87.6% response rate). The prevalence of myopia, hyperopia and astigmatism was 19.2%, 48.6% and 57.4%, respectively. 3.6% high hyperopia, 0.5% high myopia and 4.5% high astigmatism were identified. The positive simultaneous effects3 of older age (Odds Ratio (OR) = 3.14), nuclear (OR = 1.71) and posterior subcapsular (OR = 1.61) cataracts as well as the negative effects of higher levels of education (OR = 0.28) were obtained on myopia. Higher BMI was found as a risk factor for hyperopia (OR = 1.67), while older patients were less likely to be hyperopic (OR = 0.31). CONCLUSION: Higher incidence of myopia and astigmatism was found in patients aged over 70 years. It was also found that patients at older ages who suffered with cataracts were at a higher risk of myopia, while elderly people with greater BMI were at a higher risk of hyperopia.

Artificial intelligence in screening, diagnosis, and classification of diabetic macular edema: A systematic review.

We review the application of artificial intelligence (AI) techniques in the screening, diagnosis, and classification of diabetic macular edema (DME) by searching six databases- PubMed, Scopus, Web of Science, Science Direct, IEEE, and ACM- from January 1, 2005 to July 4, 2021. A total of 879 articles were extracted, and by applying inclusion and exclusion criteria, 38 articles were selected for more evaluation. The methodological quality of included studies was evaluated using the Quality Assessment for Diagnostic Accuracy Studies (QUADAS-2). We provide an overview of the current state of various AI techniques for DME screening, diagnosis, and classification using retinal imaging modalities such as optical coherence tomography (OCT) and color fundus photography (CFP). Based on our findings, deep learning models have an extraordinary capacity to provide an accurate and efficient system for DME screening and diagnosis. Using these in the processing of modalities leads to a significant increase in sensitivity and specificity values. The use of decision support systems and applications based on AI in processing retinal images provided by OCT and CFP increases the sensitivity and specificity in DME screening and detection.

Scientific Publications and Subject Clusters in the Field of Glaucoma: A Scientometric Analysis.

Purpose: To analyze the glaucoma research in the Web of Science (WoS) and Scopus to determine the top features, trends, and subject clusters. Methods: In this scientometric study, all glaucoma publications in Scopus and WoS were analyzed based on various characteristics such as authors, journals, and co-word analysis. Data analysis was conducted using both Excel and VOSviewer. Results: A gradual increase in the publication rate was found for articles in the field of glaucoma in both Scopus and WoS databases. In this regard, most publications were conducted in the USA and the University of California System. The co-word network was constituted of five clusters, including glaucoma, intraocular pressure, open-angle glaucoma, visual acuity, and optic disc. It showed that the top 10 highly cited articles were more addressed by epidemiologic studies. Conclusions: The findings of this study had a more precise vision of the previous research on the field of glaucoma. It also provided the possibility to discover hidden patterns and emerging events of a subject by explaining the most essential aspects of research and identifying the areas that need more research. The findings could be useful for authors and health policymakers in academia and countries.

Risk Factors Associated with Keratoconus in an Iranian Population.

Purpose: To determine associated factors for keratoconus (KCN) in the Iranian population. Methods: In this retrospective case-control study, 100 KCN patients and 200 age- and sex-matched individuals, who were either candidates for photorefractive keratectomy or healthy referrals from the Torfeh Eye Hospital, were included as the case and control groups, respectively. KCN patients were all registered at the Iranian National Registry of Keratoconus (KCNRegⓇ). Demographic characteristics, patients' symptoms and their habits, as well as systemic and ocular disorders were documented. Clinical examinations included best corrected visual acuity (BCVA) and refractive error measurements, biomicroscopic examination, and corneal imaging. Results: In this case group, the frequency of mild, moderate, and severe KCN was 38%, 28%, and 34%, respectively. Parental consanguinity (odds ratio [OR] = 1.758, P = 0.029), positive familial history in patients' first degree (OR = 12.533, P < 0.001) and second degree (OR = 7.52, P < 0.001) relatives, vernal keratoconjunctivitis (OR = 7.510, P = 0.003), severe eye rubbing (OR = 10.625, P < 0.001), and systemic diseases including migraine, hypertension, and thyroid disease (OR = 6.828, P = 0.021) were found as associated factors for KCN. Lesser frequency of KCN was observed in patients with Fars ethnicity (OR = 0.583, P = 0.042), with higher levels of wealth indices (OR = 0.31, P < 0.001) and higher levels of education (OR = 0.18, P = 0.024). Conclusion: Severe eye rubbing, vernal keratoconjunctivitis, parental consanguinity and positive familial history of KCN, low socioeconomic status, and low levels of education were significantly associated with KCN in our study population.

Choroidal structure investigated by choroidal vascularity index in patients with inherited retinal diseases.

PURPOSE: To evaluate the choroidal structure in patients with inherited retinal diseases (IRDs) by investigating the choroidal vascularity index (CVI). METHODS: The present study was conducted on 113 IRD patients and 113 sex- and age-matched healthy individuals. Patients' data was extracted from the Iranian National Registry for IRDs (IRDReg®). Total choroidal area (TCA) was determined between retinal pigment epithelium and choroid-scleral junction,1500 microns on either side of the fovea. Luminal area (LA) was considered as the black area corresponding to the choroidal vascular spaces, following Niblack binarization. CVI was calculated as the ratio of the LA to the TCA. CVI and other parameters were compared among different types of IRD and the control group. RESULTS: The IRD diagnosis included retinitis pigmentosa (n = 69), cone-rod dystrophy (n = 15), Usher syndrome (n = 15), Leber congenital amaurosis (n = 9), and Stargardt disease (n = 5). Sixty-one (54.0%) individuals of each of the study and control groups were male. The average CVI was 0.65 ± 0.06 in the IRD patients and 0.70 ± 0.06 in the control group (P < 0.001). Accordingly, the average of TCA and LA were 2.32 ± 0.63 and 1.52 ± 0.44 mm [1] in patients with IRDs, respectively. The measurements for the TCA and the LA were significantly lower in all subtypes of IRD (P-values < 0.05). CONCLUSION: CVI is significantly lower in patients with IRD than in healthy age-matched individuals. Choroidal changes in IRDs may be related to the changes in the lumen of the choroidal vessels rather than the stromal changes.

Myopic regression after photorefractive keratectomy: a retrospective cohort study.

Background: Myopic regression is a major complication of photorefractive keratectomy (PRK). The rates and causes vary considerably among different studies. This study aimed to investigate myopic regression at six months after myopic PRK. Methods: In this retrospective cohort study, we included all eligible patients with myopia ranging from - 0.75 to - 9 D, aged 18 to 50 years, who underwent PRK by a single surgeon with the availability of preoperative and postoperative data at six months after the initial procedure. All participants underwent comprehensive ophthalmic examinations preoperatively and at six months post-PRK. Overcorrection was planned based on the participant's age range to achieve the desired refractive result after PRK. All patients received the same postoperative antibiotic and steroid eye drops in a similar dosage regimen, and the contact lenses were removed after complete corneal epithelial healing. Based on the spherical equivalent of refraction six months after PRK, eyes without and with myopic regression were allocated into groups 1 and 2, respectively. Results: We included 254 eyes of 132 patients who underwent myopic PRK with a mean (standard deviation) age of 30.12 (7.48) years; 82 (62.12%) were women and 50 (37.88%) were men. The frequency of myopic regression was significantly lower in patients with younger age, lower preoperative cylindrical refraction, and lower ablation depth (all P < 0.05). Overcorrection was more successful in eyes with low myopia than in eyes with high myopia (P < 0.05). The highest frequency of myopic regression occurred in eyes with moderate myopia (25.68%), followed by eyes with high myopia (20.0%) and low myopia (6.54%). Among different age groups, patients aged ≤ 30 years had a lower frequency of myopic regression. The frequency of myopic regression in the different age groups was 5.0% at 18 - 20 years, 7.46% at 26 - 30 years, 12.28% at 21 - 25 years, 21.31% at 31 - 35 years, and 26.53% at 36 - 50 years. Conclusions: Overcorrection was more successful in eyes with low myopia than in eyes with high myopia. The success rate was higher in younger patients with lower astigmatism and ablation depths. Myopic regression was most frequent in eyes with moderate myopia, followed by those with high and low myopia. Further studies should replicate our findings over a longer follow-up period with a larger sample size before generalization is warranted.

A health terminological system for inherited retinal diseases: Content coverage evaluation and a proposed classification.

PURPOSE: To present a classification of inherited retinal diseases (IRDs) and evaluate its content coverage in comparison with common standard terminology systems. METHODS: In this comparative cross-sectional study, a panel of subject matter experts annotated a list of IRDs based on a comprehensive review of the literature. Then, they leveraged clinical terminologies from various reference sets including Unified Medical Language System (UMLS), Online Mendelian Inheritance in Man (OMIM), International Classification of Diseases (ICD-11), Systematized Nomenclature of Medicine (SNOMED-CT) and Orphanet Rare Disease Ontology (ORDO). RESULTS: Initially, we generated a hierarchical classification of 62 IRD diagnosis concepts in six categories. Subsequently, the classification was extended to 164 IRD diagnoses after adding concepts from various standard terminologies. Finally, 158 concepts were selected to be classified into six categories and genetic subtypes of 412 cases were added to the related concepts. UMLS has the greatest content coverage of 90.51% followed respectively by SNOMED-CT (83.54%), ORDO (81.01%), OMIM (60.76%), and ICD-11 (60.13%). There were 53 IRD concepts (33.54%) that were covered by all five investigated systems. However, 2.53% of the IRD concepts in our classification were not covered by any of the standard terminologies. CONCLUSIONS: This comprehensive classification system was established to organize IRD diseases based on phenotypic and genotypic specifications. It could potentially be used for IRD clinical documentation purposes and could also be considered a preliminary step forward to developing a more robust standard ontology for IRDs or updating available standard terminologies. In comparison, the greatest content coverage of our proposed classification was related to the UMLS Metathesaurus.

Peripapillary Capillary Network in Methanol Induced Optic Neuropathy.

PURPOSE: To present the optical coherence tomography angiography (OCT-A) findings of the radial peripapillary capillary (RPC) network in an individual with severe bilateral methanol-induced toxic optic neuropathy (MTON) in comparison to a normal subject and a patient with retinitis pigmentosa. CASE REPORT: A 35-year-old man with severe bilateral MTON was referred to the neuro-ophthalmology clinic at the Labbafinejad Medical Center. The Angio Vue OCT 3D set of 4.5 × 4.5 mm was used to measure the disc and peripapillary vessel density. Two subjects were examined with the same protocol as controls to determine the effect on the RPC vessel density in multiple scenarios. One of the controls was a healthy individual with the prerequisite matches of age and sex while the second one was a known retinitis pigmentosa (RP) patient. RPC density was measured as 37.7 in the patient with MTON, 46.9 in the RP patient, and 54.7 in the healthy control. CONCLUSION: The reduction in the RPC vessel density in a patient with MTON compared to that of a healthy individual and also a patient with RP may be due to the loss of capillaries secondary to the loss of nerve fibers and ganglion cells. Moreover, MTON can be considered an optic neuropathy with direct mitochondrial damage to the endothelial cells of the capillaries.