Copper, Lysyl Oxidase Activity, and Collagen in Aqueous Humour of Primary Glaucoma: An Association with Clinical Parameters.

INTRODUCTION: To measure copper (Cu), lysyl oxidase (LOX) activity, and collagen levels in aqueous humour (AH) of primary glaucoma patients and correlate with clinical parameters. METHODS: 120 patients with 40 each of primary open angle glaucoma (POAG), primary angle closure glaucoma (PACG), and cataract controls were recruited in this case-control study. AH samples were collected during the trabeculectomy and cataract surgeries. Cu levels were measured using an atomic absorption spectrophotometer. LOX unit activity was determined by Amplex Red assay and collagen concentration by Sirius red assay. RESULTS: Significantly higher levels of Cu expressed as median (IQR) µmol/L were observed in POAG (p = 0.008) and PACG (p = 0.005) compared to controls. The LOX activity was increased in POAG and PACG (p = 0.04) compared to controls represented as median (IQR) µmol/min. The collagen levels given as median (IQR) mg/ml showed an insignificant increase in POAG and PACG compared to controls (p = 0.78). The LOX unit activity was correlated with visual field index (VFI), which showed a significant increase with the progression of the diseases (p < 0.05), whereas Cu levels were negatively correlated with LOX activity in AH. Cu and LOX activity showed weak correlation with YAG peripheral iridotomy (YAGPI), duration of anti-glaucoma medications, and highest preoperative intraocular pressure. CONCLUSION: Elevated Cu and LOX activity was observed in both POAG and PACG groups compared to controls. LOX activity showed notable increase with VFI as the severity of the disease. Although Cu levels are increased in glaucoma, it's insufficient to significantly increase the activity of LOX.

Increased Desmosine in the lens capsules is associated with augmented elastin turnover in Pseudoexfoliation syndrome.

Pseudoexfoliation syndrome (PXF) is an idiopathic disease with a high prevalence rate. The elastosis disorder is contributed by genetic and non-genetic factors. Elastin dysregulation associated with the disease mechanism is incompletely understood. This study evaluated the molecules of the elastogenesis machinery in PXF. Lens capsule and aqueous humor (aqH) samples (age/sex-matched) were collected from the eyes with PXF alone and PXF with glaucoma (PXF-G) undergoing Extra Capsular Cataract Extraction (ECCE) surgery. The Elastin turnover was assessed by estimating Desmosine levels in the lens capsules by HPLC analysis. Expression of elastogenesis genes [EMILIN1, CLU, FBN1, FN1, FBLN5, FBLN4 and LOXL1] were evaluated in the lens capsule by qPCR while the proteins were assessed in aqH by western blot analysis. The Desmosine content in the lens capsules were 3-fold and 6-fold elevated in PXF (P = 0.02) and PXF-G (P = 0.01) respectively compared to the cataract-alone, indicating increased elastin degradation. A significant increase in the transcript levels of the CLU, FBLN4, EMILIN1, FBLN5, FN1, FBN1, LOXL1 along with significant changes in protein expression of CLU, FBLN5, FBN1 and LOXL1 signified up-regulation of the elastogenesis machinery. The study provides direct evidence of augmented elastin degradation and turnover in the lens capsule of PXF marked by increased Desmosine content and the expression of proteins involved in mature elastin formation.

Anti-glaucoma medications lowered decorin and altered profibrotic proteins in human tenon's fibroblasts.

Long term exposure to anti-glaucoma medications (AGMs) leads to an increase in extracellular matrix (ECM) accumulation in primary glaucoma patients. This study aims to evaluate the effect of topical AGMs in primary human tenon's fibroblasts (HTFs) and analyze the expression of profibrotic and anti-fibrotic proteins. Primary HTFs were cultured from patients undergoing cataract (control) and trabeculectomy. The different types of AGMs in single/multiple combinations (BB, PG, AA, CAI, CH, combinations of 3- PG + AA + CAI, 4A- BB + PG + AA + CAI, 4B- BB + PG + CAI + CH and 5- BB + PG + AA + CAI + CH) on chronic exposure were tested for cell viability using MTT assay and morphological alterations. Profibrotic proteins mainly SPARC, LOXL2, COL1A1 and anti-fibrotic DCN were analyzed in treated HTFs using q-PCR and ELISA. Sirius red staining and collagen gel contraction (CGC) assay were performed to assess collagen synthesis and the contractility of HTFs, respectively. Except for AA and CH, the other AGMs at a higher concentration were found to decrease the cell viability of HTFs. The morphology of HTFs were altered on exposure to BB, CH and AA; Profibrotic proteins i.e., SPARC, LOXL2 and COL1A1 were significantly increased (p < 0.05) on exposure to a combination of AGMs with TGF-ß1, whereas the anti-fibrotic DCN expression was significantly lowered (p < 0.05) in single/multiple AGM exposure. Sirius red staining showed increased collagen synthesis with combinations of AGMs with TGF-ß1. Meanwhile, HTFs showed increased collagen gel contraction with TGF-ß1, CAI and CH. This study reveals that altered profibrotic proteins, with significantly lowered DCN on chronic exposure of AGMs in HTFs.

INTRAOCULAR PRESSURE OUTCOMES AFTER SURGERY FOR RHEGMATOGENOUS RETINAL DETACHMENT IN SCHWARTZ SYNDROME.

PURPOSE: To study intraocular pressure (IOP) outcomes after surgery for rhegmatogenous retinal detachment in Schwartz syndrome. METHODS: We reviewed records of 32 eyes of 32 patients with Schwartz syndrome (patients with rhegmatogenous retinal detachment, IOP above 21 mmHg, and open angles without angle recession, chronic steroid use or other secondary causes of increased IOP) who had undergone surgical treatment consisting of scleral buckling or vitrectomy. Intraocular pressure, number of medication, best-corrected visual acuity were compared at baseline and postsurgery visits and also studied association of various factors on long-term IOP. RESULTS: The median duration of rhegmatogenous retinal detachment was 2 months, and the inter quartile range was 1 to 12 months. Follow-up was 15 months (inter quartile range: 7-33 months). Sixteen (50%) had prior ocular trauma. Baseline IOP was 35 ± 8 mmHg, and 12% (4/32) of patients were on IOP-lowering medication at presentation. At the final visit, mean IOP was 17 ± 6 mmHg and 59% patients (19/32) required additional IOP-lowering medication or surgery for IOP control. CONCLUSION: Surgical management of rhegmatogenous retinal detachment resulted in significant reduction in IOP. At the final visit, 41% did not require any IOP-lowering medication or surgical intervention for IOP control.

Six-year incidence of visually significant age-related cataract: the Chennai eye disease incidence study.

BACKGROUND: The aim of this study is to report the 6-year incidence of age-related cataract in a population-based study. DESIGN: The design used is a population-based cohort study. PARTICIPANTS: A cohort of 2484 phakic subjects, aged 40 years and above at baseline, from a south Indian population was included in the study. METHODS: Bilateral phakics with visual acuity of 6/12 or better and cataract less than N2, C2 and P2 on the Lens Opacities Classification System II at baseline were included. Subjects with glaucoma and corneal or retinal diseases were excluded. Incident visually significant cataract was defined as visual acuity of less than 6/18 with a corresponding one grade or greater change in Lens Opacities Classification System II or history of having undergone cataract surgery with evidence of pseudophakia or aphakia at the 6-year follow-up. MAIN OUTCOME MEASURES: Six-year incidence of visually significant cataract and associated risk factors data were collected. RESULTS: Incident visually significant cataract at 6 years was seen in 158 subjects (6.36%, 95% CI: 5.40-7.32, phakics:pseudophakics/aphakics 70:88). Incidence was higher in the rural cohort as compared with the urban cohort (P < 0.001). Incidence increased with age and was highest in the ≥70 years age group (odds ratio (OR):31.23, 95% CI: 15.20-64.16, P < 0.001). Other associated risk factors included illiteracy (OR 1.75, 95% CI: 1.17-2.61, P = 0.007) and smoking (OR 1.77, 95% CI: 1.08-2.88, P = 0.02). CONCLUSIONS: A significant proportion of the population developed visually significant age-related cataract at 6 years. Incident visually significant cataract was significantly greater for the rural cohort between 50 and 69 years old.

Six-Year Incidence and Baseline Risk Factors for Pseudoexfoliation in a South Indian Population: The Chennai Eye Disease Incidence Study.

OBJECTIVE: To estimate the 6-year incidence of pseudoexfoliation and its risk factors in a South Indian population. DESIGN: Longitudinal population-based study. PARTICIPANTS: Subjects 40 years of age or older without pseudoexfoliation at baseline. METHODS: Participants were examined at baseline and after a 6-year interval. The presence of pseudoexfoliation was looked for after pupillary dilation in either or both eyes at 1 or more locations. Glaucoma was defined using the International Society of Geographical and Epidemiological Ophthalmology Classification. Logistic regression was performed to identify the baseline risk factors that could predict the incident pseudoexfoliation. MAIN OUTCOME MEASURES: Six-year incidence, associated risk factors, and rural-versus-urban differences. RESULTS: From the study cohort of 4228 subjects, 87 subjects (male-to-female ratio, 48:39; rural-to-urban ratio, 69:18) demonstrated incident pseudoexfoliation (2.03%; 95% confidence interval [CI], 1.6-2.5; rural: -2.86%; 95% CI, 1.6-2.5; urban: 0.96%; 95% CI, 0.5-1.4). Pseudoexfoliation was associated with glaucoma in 1 subject (1.1%), with primary angle-closure suspicion in 10 subjects (11.5%), and with ocular hypertension in 2 subjects (2.2%). Significant predictive baseline risk factors were older age (P < 0.001), rural residence (P < 0.001), illiteracy (P = 0.02), pseudophakia (P = 0.04), and nuclear cataract (P = 0.05). With reference to the 40-to-49-year age group, the risk of incidence increased from 4.7 (95% CI, 2.4-9.4) for the 50-to-59-year age group to 12.9 (95% CI, 6.1-27.2) for 70 years of age and older group. CONCLUSIONS: In 6 years, pseudoexfoliation developed in 2.03% of the population. Rural and urban incidence was significantly different.

Predictors for incidence of primary open-angle glaucoma in a South Indian population: the Chennai eye disease incidence study.

OBJECTIVE: To determine the 6-year incidence of primary open-angle glaucoma (POAG) and its associated predictors. DESIGN: Population-based cohort study. PARTICIPANTS: A total of 4316 subjects without POAG at baseline who were 40 years of age and older from a south Indian population. METHODS: Participants were examined at baseline and after a 6-year interval. Detailed ophthalmic examination included applanation tonometry, gonioscopy, pachymetry, optic disc evaluation, and automated perimetry. Glaucoma was defined using the International Society of Geographical and Epidemiological Ophthalmology Classification. Multivariable logistic regression was performed to identify the baseline risk factors that could predict the incident POAG. MAIN OUTCOME MEASURES: Six-year incidence of POAG and its associated risk factors. RESULTS: In 6 years, incident POAG developed in 129 subjects (2.9%; 95% confidence interval [CI], 2.4-3.4; male-to-female ratio, 65:64). Baseline age was a risk factor. In reference to the group 40 to 49 years of age, the incidence increased from 2.3 (95% CI, 1.4-3.7) for the group 50 to 59 years of age to 3.5 (95% CI, 2.2-5.7) for the group 60 to 69 years of age (P<0.001). Other baseline risk predictors were urban residence (odds ratio [OR], 1.6; 95% CI, 1.1-2.2; P = 0.01), higher intraocular pressure (IOP; OR, 2.0; 95% CI, 1.5-2.6 per 10 mmHg; P<0.001), myopia (OR, 1.7; 95%, CI, 1.1-2.5; P<0.001), and axial length (OR, 1.5; 95% CI, 1.0-2.2 per millimeter; P = 0.03). Thinner corneas with higher IOP at baseline had the highest incidence of POAG. In 80% of the urban population and 100% of the rural population, incident glaucoma was previously undetected. CONCLUSIONS: A significant proportion of this population demonstrated incident POAG. The baseline risk factors could help in identifying those at highest risk of disease.

Understanding the treatment paradigm and the sequencing of antiglaucoma fixed-dose combinations in a tertiary center in South India.

PURPOSE: To analyze the medical management of primary open-angle glaucoma (POAG) and ocular hypertension (OHT) and the placement of fixed-drug combination drugs (FDC) in the treatment paradigm at a tertiary eye care center in South India. METHODS: Retrospective study (January 2011-December 2015) of newly diagnosed POAG and OHT patients (≥18 years) with ≥5 years follow-up. Primary outcome included percentage use of different antiglaucoma drugs (at initiation) and FDCs at the first, second, and third progression (sequencing). Secondary outcomes: Percentage discontinuation for different FDCs, efficacy parameters (decrease in intraocular pressure (IOP)/visual field), adverse events, and the median number of antiglaucoma medications (AGMs) after 5 years. RESULTS: Three hundred and seventy eyes (198 patients) were analyzed; 84% of them had POAG. Prostaglandin analogs (PGAs) were the most common (66.2%). FDCs were started in 48 eyes (12.9%), with brimonidine + timolol combination being the most common. FDC usage at subsequent modifications was 10.1%, 24.04%, and 30.0%. Beta-blockers and PGAs were the most frequently prescribed AGMs in our practice pattern, with ß-blockers being the most consistent one. CONCLUSION: This study is a fairly large study with a minimum of a 5-year follow-up of patients with POAG and OHT and gives insights into the treatment patterns, use of FDCs, and the need for multiple medications over time.

Effect of beta blockers on optical coherence tomography angiography in normal, suspect, and glaucomatous eyes: A prospective study.

PURPOSE: The study aimed to assess the effect of hypertension, and use of systemic beta blockers (BB) and other antihypertensives on ocular perfusion by optical coherence tomography angiography (OCTA) in normal, suspect, and glaucomatous eyes. METHODS: Cross-sectional study in tertiary eye care center. Prospectively recruited consenting subjects between 18 and 90 years with or without glaucoma. Measured the optic nerve peripapillary perfusion and flux and macular vessel density (MVD: 6 × 6 and 3 × 3 mm) in the superficial retinal layer using OCTA. RESULTS: Included 200 eyes (112 patients). Compared to nonhypertensives or those on non-BB antihypertensives (NBB), hypertensives on BB had lower peripapillary perfusion (43.45,43.40, 42.05%, P = 0.003), and MVD (6 × 6 mm: 16.65, 16.70,15.75 mm/mm 2 , P = 0.002; 3 × 3 mm: 18.70, 18.50, 18.00 mm/mm 2 , P = 0.025). Those on systemic BB with vasodilatory properties had similar perfusion parameters as nonhypertensives and NBB. Those on systemic BB without vasodilating properties had significantly lower peripapillary perfusion (42.05 vs 43.30%, P = 0.011) and MVD (6 × 6 mm: 15.15 vs 16.60 mm/mm 2 , P < 0.001; 3 × 3 mm: 17.40 vs 18.70 mm/mm 2 , P = 0.005) compared to nonhypertensives. On multivariate analysis, peripapillary perfusion increased with increase in diastolic blood pressure (ß:0.051, p: 0.04) and increasing age was the only factor found to be significantly associated with decreased peripapillary and macular perfusion parameters. CONCLUSION: Systemic BB users have worse ocular perfusion parameters compared to those on other medications or nonhypertensives on univariate analysis but similar perfusion on multivariate analysis. Those on BB with vasodilation have better ocular perfusion parameters. All BB cannot be considered equally detrimental to ocular perfusion. Further well-controlled prospective studies are needed to reassess the effects of BB with or without vasodilation on ocular perfusion.

Comparison of conjunctiva-related complications between scleral and corneal patch grafts in Ahmed glaucoma valve implantation.

Purpose: Comparison of the conjunctiva related complication rates and success rates among eyes with Ahmed glaucoma valve (AGV) implantation in which eye bank derived scleral and corneal patch grafts had been used to cover the tube. Methods: Retrospective comparative study. Patients who underwent AGV implantation between January 2000 to December 2016 were included. Demographic, clinical data, intra and post operative data was obtained from electronic medical records. Conjunctiva related complications were divided into two groups: with and without implant exposure. Conjunctiva related complication rates, success rate, risk factors among eyes with corneal and scleral patch graft were compared. Results: Three hundred and twenty three eyes of 316 patients underwent AGV implantation. Scleral patch graft was used in 214 eyes of 210 patients (65.9%) and corneal patch graft was used in 109 eyes of 107 patients (34%). Median follow up was 14 months. There was no significant difference in the conjunctiva related complication rate (7.3 % in corneal patch graft versus 7.0% in scleral patch graft;p=0.5) and conjunctival dehiscence rate (3.7% versus 4.6%, P = 0.7) among the two groups. Success rate was significantly higher in the corneal patch graft group versus the scleral patch graft group (98% versus 72%; p=0.001). Eyes with corneal patch graft had a higher survival rate (P = 0.01). Conclusion: There was no significant difference in the rate of conjunctiva related complications following corneal and scleral patch grafts used to cover the AGV tube. Eyes with corneal patch graft had a higher success rate and survival rate.

Examination under anesthesia: Preferred Practice.

Pediatric ocular examinations are often a challenge in the outpatient setting due to limited cooperation of the child. Hence an evaluation under anesthesia (EUA) or sedation is important for a holistic ophthalmic examination. It can be combined with short procedures, such as suture removal and corneal scrappings, both for diagnosis and for the management of several ophthalmic disorders. It can also be performed before planning a surgical intervention to record the baseline characters and formulate or refine a surgical plan. Every EUA must be used as a chance to perform a complete ophthalmic examination rather than perform a single task such as recording the intraocular pressure. This article aims to provide a protocol that can be followed for a complete EUA.

Change in iris parameters with physiological mydriasis.

PURPOSE: A pilot study to analyze the association of change in iris parameters with physiological mydriasis in angle closure eyes compared with normal control eyes among south Indian participants. METHODS: Sixteen eyes diagnosed with primary angle closure and 14 age, gender-matched open-angle control eyes were selected. All participants underwent anterior segment imaging using anterior segment optical coherence tomography in dim and bright illumination. The iris area (IA), iris volume (IV), and pupillary diameter were calculated using customized image processing software. RESULTS: The IA and IV were found to be lesser in angle closure compared with normal controls. Average IA (dim and bright) was found to be 3.4 and 3.7 mm(2) in normals and 3.03 and 3.35 mm(2) in angle closure, and average IV (dim and bright) was found to be 24.28 and 26.09 mm(2) in normals and 21.38 and 22.6 mm(2) in angle closure. The IA and IV decreased significantly with pupillary dilation in normals and in angle closures. However, decrease in the IA (slope = 0.52 and 0.42; p = 0.012) and IV (slope = 1.97 and 1.41; p = 0.014) with pupillary dilation was significantly higher in normals compared with angle closures, respectively. CONCLUSIONS: IA and IV were found to decrease as pupil dilates in normal and angle closure eyes among South Indians. Loss in the IV was found to be lower in angle closure eyes.

Blindness in glaucoma: primary open-angle glaucoma versus primary angle-closure glaucoma-a meta-analysis.

AIM: To estimate the risk of blindness with primary angle-closure glaucoma (PACG) compared to primary open-angle glaucoma (POAG) in those population-based studies that reported blindness rates for both PACG and POAG. METHOD: A systematic search was performed in PubMed for articles published in English between 2000 and 2020 reporting the prevalence of POAG as well as PACG among various ethnic populations. A study was included if it was (1) population-based (2) had published prevalence and blindness rates for both PACG and POAG in the same cohort. (3) Glaucoma was defined as per the International Society for Geographical and Epidemiological Ophthalmology (ISGEO) criteria. The proportion of blindness for both POAG and PACG for each study and the cumulative proportion taking all the studies were calculated. RESULTS: We included 23 studies with 78,434 participants. POAG was diagnosed in 1702 persons with 151 (8.9%) blind. There were 724 cases of PACG with 196 (27.0%) blind. The risk ratio of blindness in PACG to POAG varied from 0.73 to 10.6 among the studies. The cumulative risk ratio was 2.39 (95% confidence interval (CI); 1.99, 2.87). Risk ratios for studies including visual field restriction while defining blindness were similar to studies that did not (1.92 vs 2.64, P = 0.11). Risk ratios were also similar for studies that used greater than 2 instead of 3 or more quadrants of iridotrabecular contact to define angle closure (2.79 vs 2.25). CONCLUSION: Primary angle-closure disease is more likely to be associated with blindness.

Outcomes of medical and surgical management in eyes with idiopathic elevated episcleral venous pressure.

Purpose: Idiopathic elevated episcleral venous pressure (IEEVP) is a rare cause of secondary glaucoma and is a diagnosis of exclusion. The aim of this study was to describe the clinical presentation and analyze the outcomes of medical and surgical management in eyes diagnosed with idiopathic elevated episcleral venous pressure. Methods: A retrospective analysis of eyes diagnosed with IEEVP over a 5-year period between April 2012 and March 2016 was performed. The demographic details, medical history, and clinical course of the cases were obtained from the medical records. Data pertaining to the severity of glaucomatous damage, response to medical management, need for surgical intervention, and their outcomes were analyzed. Results: Fifteen eyes of 13 patients were included. Thirteen eyes (86.6%) had open angle configuration. Among the 13 eyes that had glaucoma, eight eyes (61.5%) had severe glaucoma, four eyes (30.7%) had moderate glaucoma, and one eye (7.6%) had mild glaucoma. The median follow-up was 210 days. Seven of the 15 eyes (46.6%) required a glaucoma filtration procedure, and three underwent prophylactic sclerotomies. 71.4% of these eyes had complete success. One out of the seven operated eyes required choroidal drainage post-operatively. Conclusion: IEEVP is an extremely rare condition and presents with raised intra-ocular pressure and tortuous episcleral vessels. The management of IEEVP is similar to that of primary open angle glaucoma. Uveal effusion is to be anticipated, and hence, combining trabeculectomy with prophylactic sclerotomies is advisable.

Long Anterior Zonules and Angle Closure Disease.

PRCIS: Angle closure disease was present in 59.3% of eyes with long anterior zonules (LAZ). The cause is multifactorial including a thick anteriorly positioned crystalline lens, shorter axial length, and increased lens thickness to axial length factor. PURPOSE: To study the profile of eyes with LAZ presenting in a glaucoma clinic in a tertiary eye care centre and understand the pathogenesis of angle closure disease in these eyes. METHODS: This was a retrospective cross-sectional study.All patients with LAZ seen from January 2014 to December 2018 were included. Demographic and clinical characteristics were noted. LAZ eyes (177 eyes of 177 patients) were compared with an equal number of age and sex-matched controls. LAZ was defined as radially oriented zonular fibers (both pigmented and nonpigmented), extending central to the normal zonular termination zone on the anterior lens surface >1 mm beyond their usual insertion of 1.42±0.24 mm from the lens equator onto the mid peripheral zone or central to it, as seen on slit-lamp examination, following pupillary dilation by a single examiner. Glaucoma was defined according to the International Society for Geographical and Epidemiological Ophthalmology classification. The following biometric parameters were compared: anterior chamber depth (ACD), axial length (AXL), lens thickness (LT), lens position (LP=ACD+0.5×LT), relative lens position (RLP=LP/AXL); lens thickness to axial length factor (LAF=(LT/AXL)×10). LAZ eyes without angle closure disease were also compared with controls. RESULTS: Mean age of patients with LAZ was 64.8±8.1 years. Of these, 63.3% were females. Angle closure disease was present in 59.3% (105/177) patients. Majority of these eyes were primary angle closure suspects (PACS) (53.3%, n=56). Significant differences were found between LAZ eyes and controls for LT (4.8±0.38 mm vs. 4.49±0.40 mm, P<0.0001), ACD (2.68±0.39 mm vs. 3.0±0.32 mm, P<0.0001), AXL (22.37±0.79 mm vs. 22.94±1.1, P<0.0001), LAF (2.14±0.19 vs. 1.96±0.21, P<0.0001), and LP (5.07±0.37 vs. 5.3±0.25, P<0.0001). CONCLUSIONS: Angle closure was present in more than half the eyes with LAZ. Majority of these eyes were PACS or had primary angle closure. LAZ eyes had a thicker lens, shallow AC, a shorter axial length and an increased LAF as compared with age and sex matched normal controls. The presence of LAZ may be an indicator of increased risk for angle closure.

Effective refractive error coverage in adults aged 50 years and older: estimates from population-based surveys in 61 countries.

BACKGROUND: In 2021, WHO Member States endorsed a global target of a 40-percentage-point increase in effective refractive error coverage (eREC; with a 6/12 visual acuity threshold) by 2030. This study models global and regional estimates of eREC as a baseline for the WHO initiative. METHODS: The Vision Loss Expert Group analysed data from 565 448 participants of 169 population-based eye surveys conducted since 2000 to calculate eREC (met need/[met need + undermet need + unmet need]). A binary logistic regression model was used to estimate eREC by Global Burden of Disease (GBD) Study super region among adults aged 50 years and older. FINDINGS: In 2021, distance eREC was 79·1% (95% CI 72·4-85·0) in the high-income super region; 62·1% (54·7-68·8) in north Africa and Middle East; 49·5% (45·0-54·0) in central Europe, eastern Europe, and central Asia; 40·0% (31·7-48·2) in southeast Asia, east Asia, and Oceania; 34·5% (29·4-40·0) in Latin America and the Caribbean; 9·0% (6·5-12·0) in south Asia; and 5·7% (3·1-9·0) in sub-Saharan Africa. eREC was higher in men and reduced with increasing age. Global distance eREC increased from 2000 to 2021 by 19·0%. Global near vision eREC for 2021 was 20·5% (95% CI 17·8-24·4). INTERPRETATION: Over the past 20 years, distance eREC has increased in each super region yet the WHO target will require substantial improvements in quantity and quality of refractive services in particular for near vision impairment. FUNDING: WHO, Sightsavers, The Fred Hollows Foundation, Fondation Thea, Brien Holden Vision Institute, Lions Clubs International Foundation.

Association of metformin use among diabetics and the incidence of primary open-angle glaucoma - The Chennai Eye Disease Incidence Study.

PURPOSE: Studies have reported the usage of metformin being associated with the reduced risk of progression of glaucoma. The current study aims to determine the association of metformin usage among subjects with diabetes mellitus and the six-year incidence of primary open-angle glaucoma (POAG). METHODS: In this prospective cohort study, subjects who did not have glaucoma at the baseline and had a follow-up after a six-year interval were included. Details such as medical and drug history, applanation tonometry, gonioscopy, pachymetry, optic disc evaluation, and automated perimetry were collected. Incident POAG was defined as subjects who do not have glaucoma at baseline and developed glaucoma as classified International Society of Geographical and Epidemiological Ophthalmology Classification at the follow-up. The association between the subjects who were on metformin for treatment of diabetes mellitus and development of incident POAG was assessed. RESULTS: Among the 4302 eligible participants, 128 (3%) had incident POAG. There were 905 (21.0%) subjects who had diabetes mellitus of which 142 (15.7%) were using metformin. Of the subjects with POAG, 92 (71.9%) were nondiabetics and 36 were diabetics (28.1%). Among the diabetics, the incidence of POAG among those on metformin was 5.6% (8 participants) and those not on metformin was 3.6% (28 participants). There was no difference in the incidence of POAG in subjects with diabetes mellitus, with and without metformin use (P = 0.25). Logistic regression showed no association of metformin use with the incidence of POAG (OR: 1.33, 95 CI: 0.58-3.04, P = 0.49) after adjusting for age, gender, and place of residence. CONCLUSION: The current study did not find any association between the effects of metformin on the incidence of POAG.

Tube Obstruction of a Nonvalved Glaucoma Drainage Device by a Dislocated Soemmering's Ring.

The authors report a case of tube obstruction of a nonvalved glaucoma drainage device (Aurolab aqueous drainage implant; AADI) with a dislocated Soemmering's ring (SR) leading to a postoperative intraocular pressure (IOP) spike after an initial IOP reduction. A 24-year-old man with bilateral aphakia, bilateral secondary glaucoma developed corneal decompensation in the left eye. The IOP in the left eye was 22 mm Hg with 3 topical IOP-lowering medications (timolol 0.5%, brimonidine 0.2%, and latanoprost 0.005%). To control the IOP before performing a penetrating keratoplasty, AADI was implanted. A good bleb and an IOP of 10 mm Hg were noted at 6.5 weeks postoperatively. The following day the patient developed an acute rise in IOP (42 mm Hg) because of tube obstruction of the AADI by a SR. The IOP spike was initially controlled with oral acetazolamide and topical IOP-lowering medications (fixed combination of timolol 0.5% and brimonidine 0.2%). Six days later, pars plana vitrectomy, SR removal, penetrating keratoplasty, and tube trimming were performed. Following this, the patient had good IOP control and a clear corneal graft at 1-year follow-up. In aphakic eyes undergoing nonvalved glaucoma drainage device implantation, a complete pars plana vitrectomy combined with any lens remnant removal may be considered. It helps to avoid tube obstruction because of these lens remnants, which can migrate anteriorly along with the aqueous currents.

Neovascular glaucoma - A review.

Neovascular glaucoma (NVG) is a sight-threatening secondary glaucoma characterized by appearance of new vessels over the iris and proliferation of fibrovascular tissue in the anterior chamber angle. Retinal ischemia is the common driving factor and common causes are central retinal vein occlusion, proliferative diabetic retinopathy, and ocular ischemic syndrome. The current rise in the prevalence of NVG is partly related to increase in people with diabetes. A high index of suspicion and a thorough anterior segment evaluation to identify the early new vessels on the iris surface or angle are essential for early diagnosis of NVG. With newer imaging modalities such as the optical coherence tomography angiography and newer treatment options such as the anti-vascular endothelial growth factor, it is possible to detect retinal ischemia early, tailor appropriate treatment, monitor disease progression, and treatment response. The management strategies are aimed at reducing the posterior segment ischemia, reduce the neovascular drive, and control the elevated intraocular pressure. This review summarizes the causes, pathogenesis, and differential diagnoses of NVG, and the management guidelines. We also propose a treatment algorithm of neovascular glaucoma.

Central corneal thickness in adult South Indians: the Chennai Glaucoma Study.

OBJECTIVE: To evaluate the characteristics of central corneal thickness (CCT) and its association with age, gender, and intraocular pressure in rural and urban South Indian populations. DESIGN: Population-based cross-sectional study. PARTICIPANTS: Seven thousand seven hundred seventy-four subjects (rural-to-urban ratio, 3924:3850) aged 40 years and older were examined at a dedicated facility in the base hospital. INTERVENTION: All subjects underwent a complete ophthalmic examination that included CCT measurements with an ultrasonic pachymeter and applanation tonometry. MAIN OUTCOME MEASURES: Central corneal thickness. RESULTS: Of the 7774 subjects examined, 974 had undergone cataract surgery and were excluded. The remaining 6800 were bilaterally phakic, of which 46 were excluded (17 glaucoma subjects receiving treatment, 12 with corneal pathologic features and 17 with incomplete data) and 6754 subjects data were analyzed. The mean CCT for the population was 511.4+/-33.5 microm, and CCT in males (515.6+/-33.8 microm) was significantly (P = 0.0001) greater than females (508.0+/-32.8 microm). The CCT was significantly greater (by 18 microm) in the urban population and decreased with age in both genders (P<0.0001). The decrease per decade was 4.34 microm (95% confidence interval [CI], 3.24-5.44) in the rural population and 2.41 microm (95% CI, 1.25-3.53) in the urban population. A 100-microm increase in CCT was associated with a 1.96-mmHg increase in intraocular pressure in the rural population, versus 2.45 mmHg for every 100 microm in the urban population. CONCLUSIONS: In this population-based study, females and subjects living in a rural area had thinner corneas. A negative association with age and a positive association with intraocular pressure were seen. These findings will have implications in the diagnosis and management of glaucoma in this population. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.