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Progressive optic neuropathies such as glaucoma are major causes of blindness globally. Multiple sources of subjectivity and analytical challenges are often encountered by clinicians in the process of early diagnosis and clinical management of these diseases. In glaucoma, the structural damage is often characterized by neuroretinal rim (NRR) thinning of the optic nerve head, and other clinical parameters. Baseline structural heterogeneity in the eyes can play a key role in the progression of optic neuropathies, and present challenges to clinical decision-making. We generated a dataset of Optical Coherence Tomography (OCT) based high-resolution circular measurements on NRR phenotypes, along with other clinical covariates, of 3973 healthy eyes as part of an established clinical cohort of Asian Indian participants. We introduced CIFU, a new computational pipeline for CIrcular FUnctional data modeling and analysis. We demonstrated CIFU by unsupervised circular functional clustering of the OCT NRR data, followed by meta-clustering to characterize the clusters using clinical covariates, and presented a circular visualization of the results. Upon stratification by age, we identified a healthy NRR phenotype cluster in the age group 40-49 years with predictive potential for glaucoma. Our dataset also addresses the disparity of representation of this particular population in normative OCT databases., (© 2021. The Author(s).)

Objectives: To assess the ability of teleophthalmoscopic grading of peripheral anterior chamber depth (PACD) using the van Herick (vH) technique in detecting gonioscopically occludable angle; and to determine whether combining results from vH grading and ocular biometry can improve the accuracy to diagnose gonioscopically occludable angle METHODS: This cross-sectional study was an offshoot of a rural population-based study, Glaucoma Epidemiology and Molecular Genetic Study (GLEAMS). A masked urban ophthalmologist graded digital slit lamp photographs of PACD by vH technique. Sussman four-mirror lens was used to perform dark room indentation gonioscopy. Cutoff values of the tests were, vH technique: grade ≤ 2, central anterior chamber depth (ACD), as well as axial length: ≤ 25th percentile and lens thickness ≥ 75th percentile value of the study population., Results: We studied 1965 eyes of 1029 adult participants. The vH grade was ≤2 in 188 (9.5%) eyes. The angle was occludable by gonioscopy in 101 (5.1%) eyes. The performance of the vH test to rule out gonioscopically occludable angle was good [negative predictive value (NPV): 97.3%], despite low sensitivity (52.5%), while its efficacy to rule in the condition was low [positive predictive value (PPV): 28.2%] despite high specificity (92.8%). However, test combination strategy increased the PPV nearly twofold (53.8%). The calculated PPV at 10% prevalence of gonioscopically occludable angle was even higher (70.5%)., Conclusions: Van Herick technique can be incorporated into a teleophthalmology program by means of slit lamp photographs of PACD. Combined vH grading and ocular biometry improved the predictability of a gonioscopically occludable angle.

Purpose: To report the clinical features, treatment outcomes and blindness associated with steroid-induced glaucoma in vernal keratoconjunctivitis (VKC)., Materials and Methods: Records of patients with VKC, who visited our tertiary centre from 1992 and 2009, were reviewed and those with steroid-induced glaucoma were included in the study. Glaucoma was diagnosed based on intraocular pressure (IOP) ≥22 mm Hg on two consecutive visits (ocular hypertension) and/or glaucomatous optic disc damage. Blindness was defined as best corrected visual acuity of ≤20/400 or visual field <10°., Results: Of the 4062 VKC subjects, 91 (157 eyes) had steroid-induced glaucoma (SIG), showing a prevalence of 2.24%. Of these 87% were men. The median (IQR) age at onset of VKC was 12 years (7-17). At presentation, the median duration of VKC was 48 months (24-72) and the median duration of steroid usage was 24 months (12-36). The median cup-to-disc ratio (CDR) was 0.9 (0.7-0.9) and median mean deviation was -21.9 dB (-30.0 to -10.2). IOP was medically controlled in 66% eyes (104/157) and 34% eyes (53/157) needed glaucoma surgery. High presenting IOP (OR: 1.04; p=0.05) and increased duration of steroid usage (OR: 1.07; p=0.02) were significantly associated with need for glaucoma surgery. At presentation, 29/91 subjects (31.8%) were bilaterally blind due to SIG. Higher CDR at presentation was significantly associated with blindness in this cohort (p=0.02)., Conclusion: In this cohort of VKC with SIG, the disease predominantly affected adolescent males. Glaucoma was severe with one-third needing surgery and one-third blind due to SIG., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: To report the prevalence of primary glaucoma as identified by study optometrists of the L. V. Prasad Eye Institute - Glaucoma Epidemiology and Molecular Genetics Study (LVPEI-GLEAMS)., Methods: Two study optometrists and a total number of 3833 individuals participated in the LVPEI-GLEAMS. All subjects underwent a complete medical history and comprehensive eye examination including slit lamp photography, imaging of anterior and posterior segment, frequency doubling technology and standard automated perimetry including gonioscopy with a Sussman 4 mirror goniolens, post dilated evaluation of the optic disc and fundus was done with a 90 D lens by the study optometrist. A diagnosis of primary open angle glaucoma (POAG), primary angle closure suspect (PACS), primary angle closure (PAC), primary angle closure glaucoma (PACG), normal tension glaucoma (NTG), glaucoma/disc suspect or no glaucoma was made based on the clinical examination., Results: Estimated prevalence of OAG (POAG and NTG) was 1.07% (0.74-1.39), PACS 2.03% (1.58-2.48), PAC 1.77% (1.35-2.19), PACG 0.21% (0.06-0.35) as identified by the study optometrists on site., Conclusions: Prevalence of all the categories of primary glaucoma, as reported by the study optometrists of LVPEI-GLEAMS was comparable to previous findings of other regions in South India.

Purpose: To report the clinical features, management, and treatment outcomes of glaucoma in microspherophakia., Methods: Medical records of 159 eyes of 80 subjects with microspherophakia were reviewed. The clinical features at presentation, presence of glaucoma, methods of treatment, and their outcomes were noted. Glaucoma was diagnosed based on intraocular pressure (IOP)≥22 mm Hg on 2 different occasions and/or glaucomatous optic disc damage. Angle closure was defined as occludable angles >270 degrees with or without presence of peripheral anterior synechiae., Results: Glaucoma was diagnosed in 81 eyes (51%). The mean age of subjects was 20±13 years, mean refractive error was -13.5±5.5, the mean IOP was 27.7±11.1 mm Hg. IOP≥22 mm Hg was present in 84% of eyes, disc damage in 59% of the eyes, 75% eyes had angle closure, and 25% had open angle on gonioscopy. Subluxation of crystalline lens was seen in 53 eyes and 14 eyes had dislocation of the lens; systemic associations were present in 21 subjects (3 Marfan syndrome, 18 Weill-Marchesani syndrome). Nine eyes out of 51 and 2 out of 16 eyes responded to medical treatment and laser iridotomy, respectively. Of the 48 eyes that required surgical intervention, 24 eyes underwent trabeculectomy. Complete success probability of trabeculectomy was 86% [95% confidence interval (CI), 63%-95%] at 6 months, 77% (95% CI, 53%-90%) at 1 year, which was maintained till 7 years, and reduced to 61% (95% CI, 26%-84%) at 8 years. Nearly 20% of eyes at presentation and 30% of the eyes at last follow-up were blind due to glaucoma., Conclusions: More than half of the eyes with microspherophakia in this series presented with glaucoma; angle closure was the predominant form of glaucoma. Blindness due to glaucoma in microspherophakia was 20% to 30%.

Background: With the advent of spectral domain optical coherence tomography (SDOCT), there has been a renewed interest in macular region for detection of glaucoma. However, most macular SDOCT parameters currently are thickness parameters which evaluate thinning of the macular layers but do not quantify the extent of area over which the thinning has occurred. We therefore calculated a new macular parameter, "ganglion cell complex surface abnormality ratio (GCC SAR)" that represented the surface area over which the macular thickness was decreased., Purpose: To evaluate the ability of SAR in detecting perimetric and preperimetric glaucoma., Design: Retrospective image analysis., Materials and Methods: 68 eyes with perimetric glaucoma, 62 eyes with preperimetric glaucoma and 165 control eyes underwent GCC imaging with SDOCT. SAR was calculated as the ratio of the abnormal to total area on the GCC significance map., Statistical Analysis: Diagnostic ability of SAR in glaucoma was compared against that of the standard parameters generated by the SDOCT software using area under receiver operating characteristic curves (AUC) and sensitivities at fixed specificities., Results: AUC of SAR (0.91) was statistically significantly better than that of GCC average thickness (0.86, P = 0.001) and GCC global loss volume (GLV; 0.88, P = 0.01) in differentiating perimetric glaucoma from control eyes. In differentiating preperimetric glaucoma from control eyes, AUC of SAR (0.72) was comparable to that of GCC average thickness (0.70, P > 0.05) and GLV (0.72, P > 0.05). Sensitivities at specificities of 80% and 95% of SAR were comparable (P > 0.05 for all comparisons) to that of GCC average thickness and GLV in diagnosing perimetric and preperimetric glaucoma., Conclusion: GCC SAR had a better ability to diagnose perimetric glaucoma compared to the SDOCT software provided global GCC parameters. However, in diagnosing preperimetric glaucoma, the ability of SAR was similar to that of software provided global GCC parameters.

Purpose: In the developing world, more than 90% of glaucoma is undetected due to the lack of appropriate screening methods. The LV Prasad Eye Institute Glaucoma Epidemiology and Molecular Genetic Study (LVPEI-GLEAMS) is a population-based study which aims to estimate the prevalence of, along with clinical, systemic and genetic risk factors for glaucoma in a rural population sampled from the state of Andhra Pradesh, India. The study aims to develop community screening strategies to diagnose glaucoma. This article describes the methodology adopted in LVPEI-GLEAMS., Methods: A sample of 3833 participants aged 40 years and older has been estimated to be enrolled using a compact segment sampling method with probability proportionate to size. Each participant will undergo a complete medical history and comprehensive eye examination including slit lamp photography, imaging of anterior and posterior segment, frequency doubling technology and standard automated perimetry. Additionally, glycosylated hemoglobin will be measured and a genetic profile based on candidate gene analysis will be undertaken. Clinical, biochemical and genetic data will be stored in a computerized database and analyzed. The novelty of this study lies in the fact that it is conducted at a vision center (primary eye care center serving a population of 50,000) by a vision technician (high school educated rural youth trained in basic ophthalmic techniques for a year)., Conclusion: Information from the diagnostic techniques of the study will be used to develop effective community-level screening strategies, and insights from risk factors associated with glaucoma will help develop appropriate detection and management strategies.