Evaluation of Primary Angle-Closure Glaucoma Susceptibility Loci in Patients with Early Stages of Angle-Closure Disease.

PURPOSE: To investigate whether newly identified genetic loci for primary angle-closure glaucoma (PACG) are associated with early stage angle-closure disease defined as primary angle closure suspect (PACS). DESIGN: Case-control study. PARTICIPANTS: A total of 1397 PACS patients and 943 controls of Chinese ethnicity from Singapore and 604 PACS patients and 287 controls of Indian ethnicity. METHODS: The 8 PACG single nucleotide polymorphisms (SNPs; rs11024102 at PLEKHA7, rs3753841 at COL11A1, rs1015213 located between PCMTD1 and ST18 son chromosome 8q, rs3816415 at EPDR1, rs1258267 at CHAT, rs736893 at GLIS3, rs7494379 at FERMT2, and rs3739821 mapping in between DPM2 and FAM102A) were genotyped by Taqman assays. The association between SNP genotypes and PACS status was measured using logistic regression. A P value of 0.006 was set to account for the testing of 8 genetic loci using a Bonferroni correction. A meta-analysis was conducted to calculate the overall P value and accompanying per-allele odds ratios for each SNP analyzed. MAIN OUTCOME MEASURES: Association of PACG loci with PACS status. RESULTS: The PACS patients were significantly older in both cohorts (Chinese, P < 0.001; Indian, P = 0.002), and there were also more women (P < 0.001, both Chinese and Indian cohorts). In the Chinese cohort, significant evidence of association was noted at 3 SNPs: rs1015213 [A] in PCMTD1-ST18 (odds ratio [OR], 2.36; 95% confidence interval [CI], 1.36-4.11; P = 0.002), rs3816415 [A] in EPDR1 (OR, 1.49; 95% CI, 1.19-1.85; P < 0.001), and rs3739821 [G] in DPM2-FAM102A (OR, 1.40; 95% CI, 1.18-1.65; P < 0.001). Only PCMTD1-ST-18 was replicated modestly in the Indian population (P = 0.056). Meta-analysis showed significant evidence of association for PCMTD1-ST-18 (OR, 1.55; 95% CI, 1.18-2.04; P = 0.002) and DPM2-FAM102A (OR, 1.27; 95% CI, 1.12-1.45; P = 0.0002). CONCLUSIONS: In this study, 2 of 8 PACG-associated loci were associated significantly with PACS status, the earliest stage in the angle-closure glaucoma disease course. The association of these PACG loci with PACS status suggests that these loci may confer susceptibility to a narrow angle configuration.

Changes in Anterior Segment Morphology and Predictors of Angle Widening after Laser Iridotomy in South Indian Eyes.

PURPOSE: To compare anterior segment optical coherence tomography (ASOCT) angle morphology before and after laser peripheral iridotomy (LPI) in a cohort of South Indian subjects with primary angle-closure suspect (PACS) or primary angle-closure/primary angle-closure glaucoma (PAC/PACG) and to examine baseline parameters associated with angle widening. DESIGN: Prospective observational study. PARTICIPANTS: A total of 244 subjects aged ≥30 years with PACS or PAC/PACG in at least 1 eye. METHODS: The ASOCT images and angle gonioscopic grades were analyzed for all subjects at baseline and 2 weeks after LPI. Multivariable linear and logistic regression models were used to determine predictors of angle widening (change in mean angle opening distance [AOD750]) and angle opening (all 4 quadrants with trabecular meshwork [TM] visible on gonioscopy after LPI). MAIN OUTCOME MEASURES: Change in ASOCT parameters with LPI and baseline predictors of angle widening. RESULTS: Laser peripheral iridotomy resulted in angle widening on ASOCT with significant increases in AOD750, angle recess area, and trabecular iris surface area (P < 0.05 for all). Gonioscopically, 44.7% of all subjects had open angles in all 4 quadrants after LPI, with a greater percentage of angles open in the PACS group compared with the PAC/PACG group (52.4% vs. 36.4%; P = 0.01). In multivariable regression analyses, greater postoperative angle widening as defined by change in AOD750 was associated with shorter baseline AOD750 and axial length, and greater baseline anterior chamber depth, iris curvature, and lens vault (P ≤ 0.002 for all). Gonioscopic angle opening after LPI was more common with wider baseline angle width (modified Shaffer grade) and lower cup-to-disc ratio (P < 0.001 for both). CONCLUSIONS: In a South Indian population with PACS or PAC/PACG, LPI results in significant anterior chamber angle widening seen on both ASOCT and gonioscopy, although some degree of persistent iridotrabecular contact was present in approximately half of PACS eyes and approximately two thirds of PAC/PACG eyes on gonioscopy. The greatest widening by ASOCT was observed in eyes with features most consistent with greater baseline pupillary block.

Family history is a strong risk factor for prevalent angle closure in a South Indian population.

PURPOSE: To compare the prevalence of angle closure among siblings of patients with open angles (OAs), suspect angle closure (PACS), and either primary angle closure (PAC) or PAC glaucoma (PACG). DESIGN: Cross-sectional, clinical study. PARTICIPANTS: A total of 303 South Indian sibling pairs, including 81 OA probands, 143 PACS probands, and 79 PAC/PACG probands. METHODS: Probands and siblings underwent a clinical examination, including gonioscopy by a masked grader, applanation tonometry, slit-lamp biomicroscopy, optic nerve evaluation, and A-scan ultrasonography. Probands and siblings were classified into 1 of 3 groups based on the phenotype of the more severely affected eye: OA, PACS, or PAC/PACG. Multivariable regression models were used to estimate the odds of prevalent angle closure in PACS or PAC/PACG siblings compared with OA siblings. MAIN OUTCOME MEASURES: Prevalence and relative prevalence of angle closure and PAC/PACG among OA, PACS, and PAC/PACG siblings. RESULTS: Mean sibling age was 49.7 ± 8.7 years, and 56.6% of siblings were females. Angle closure was more prevalent in both PACS siblings (35.0%) and PAC/PACG siblings (36.7%) compared with OA siblings (3.7%; P < 0.001). There was PAC/PACG present in 11.4% of PAC/PACG siblings compared with 4.9% of PACS siblings (P = 0.07) and 0% of OA siblings (P = 0.002). In multivariable models adjusting for sibling age and sex, the odds of angle closure was 13.6 times greater in angle closure (PACS or PAC/PACG) siblings compared with OA siblings (95% confidence interval [CI], 4.1-45.0; P < 0.001). Sibling angle-closure risk was also greater in female (odds ratio [OR], 2.3; 95% CI, 1.3-4.0; P = 0.005) and older siblings (OR, 1.5 per 10-year increment; 95% CI, 1.1-2.0; P = 0.02). Siblings of PAC/PACG probands had a 2.3-fold greater odds (95% CI, 0.8-6.5) of having PAC/PACG compared with siblings of PACS probands, although the association was not significant (P = 0.13). CONCLUSIONS: In the South Indian population screened, siblings of angle-closure patients had a >1 in 3 risk of prevalent angle closure, whereas siblings of PAC/PACG patients had a >10% risk of prevalent PAC/PACG. Screening siblings of angle-closure patients is likely to be of high yield in finding undetected angle closure.

Wound modulation in glaucoma surgery: The role of anti-scarring agents.

Filtration surgery is one of the most frequently performed surgeries in the management of glaucoma, and trabeculectomy is considered the gold standard surgical technique for the same. Though trabeculectomy has been reported to have an excellent initial success rate, about 30% of them fail in 3 years, and nearly 50% of them fail in 5 years. The most significant risk of failure still seems to be wound scarring, especially episcleral fibrosis, leading to bleb failure. As a result, it is essential to explore the role of anti-scarring agents, including mitomycin C, and 5-fluorouracil in wound modulation and improving the bleb survival rate. Since these agents are widely used in trabeculectomy, it is crucial to understand the various modes of application, advantages, and adverse effects of these agents. On an evidence-based approach, all these points have been highlighted in this review article. In addition, the newer agents available for wound modulation and their scope for practical application are discussed.

Diagnostic performance of the offline Medios Artificial Intelligence (AI) for glaucoma detection in a rural tele-ophthalmology setting.

PURPOSE: This study assesses the diagnostic efficacy of offline Medios Artificial Intelligence (AI) glaucoma software in a primary eyecare setting, using non-mydriatic fundus images from Remidio's Fundus-on-Phone (FOP NM-10). AI results were compared with tele-ophthalmologists' diagnoses and with a glaucoma specialist's assessment for those participants referred to tertiary eyecare hospital. DESIGN: Prospective, cross-sectional study PARTICIPANTS: 303 participants from 6 satellite vision centers of a tertiary eye hospital METHODS: At the vision center, participants underwent comprehensive eye evaluations, including clinical history, visual acuity measurement, slit lamp examination, intraocular pressure measurement, and fundus photography using the FOP NM-10 camera. Medios AI-Glaucoma software analysed 42-degrees disc-centric fundus images, categorizing them as normal, glaucoma, or suspect. Tele-ophthalmologists who were glaucoma fellows with a minimum of 3 years of ophthalmology and 1 year of glaucoma fellowship training, masked to AI results, remotely diagnosed subjects based on the history and disc appearance. All participants labelled as disc suspects or glaucoma by AI or tele-ophthalmologists underwent further comprehensive glaucoma evaluation at the base hospital, including clinical examination, Humphrey visual field analysis (HFA), and Optical Coherence Tomography (OCT). AI and tele-ophthalmologist diagnoses were then compared with a glaucoma specialist's diagnosis. MAIN OUTCOME MEASURES: Sensitivity and Specificity of Medios AI RESULTS: Out of 303 participants, 299 with at least one eye of sufficient image quality were included in the study. The remaining 4 participants did not have sufficient image quality in both eyes. Medios AI identified 39 participants (13%) with referable glaucoma. The AI exhibited a sensitivity of 0.91 (95% CI: 0.71 - 0.99) and specificity of 0.93 (95% CI: 0.89 - 0.96) in detecting referable glaucoma (definite perimetric glaucoma) when compared to tele-ophthalmologist. The agreement between AI and the glaucoma specialist was 80.3%, surpassing the 55.3.% agreement between the tele-ophthalmologist and the glaucoma specialist amongst those participants who were referred to the base hospital. Both AI and the tele-ophthalmologist relied on fundus photos for diagnoses, while the glaucoma specialist's assessments at the base hospital were aided by additional tools such as HFA and OCT. Furthermore, AI had fewer false positive referrals (2 out of 10) compared to the tele-ophthalmologist (9 out of 10). CONCLUSION: Medios offline AI exhibited promising sensitivity and specificity in detecting referable glaucoma from remote vision centers in southern India when compared with teleophthalmologists. It also demonstrated better agreement with glaucoma specialist's diagnosis for referable glaucoma participants.

Prostaglandin analogs in ophthalmology.

Glaucoma is a major cause of irreversible blindness worldwide. Reducing intraocular pressure (IOP) is currently the only approach to prevent further optic nerve head damage. Pharmacotherapy is the mainstay of treatment for glaucoma patients. In recent years, a significant milestone in glaucoma treatment has been a transition to prostaglandin analogs (PGAs) as the first line of drugs. The rapid shift from traditional ß-blockers to PGAs is primarily due to their excellent efficacy, convenient once-a-day usage, better diurnal control of IOP, and systemic safety profiles. This review article aims to provide information regarding the various PGAs in practice and also the newer promising drugs.

Changes in emergency glaucoma care during the COVID-19 pandemic in South India.

Purpose: To assess the differences in the pattern of presentation of glaucoma emergency conditions during the various phases of pandemic-related travel restrictions: first wave-related lockdown, unlock period, and the second wave-related lockdown. Methods: The number of new emergency glaucoma conditions, the various diagnoses, and the total number of all new glaucoma patients presenting to the glaucoma services at five tertiary eye care centers in south India from 24th March 2020 to 30th June 2021 were collected from the electronic medical records and were analyzed. The data were compared with the corresponding time period in the year 2019. Results: In total, 620 patients presented with an emergency glaucoma diagnosis during the first wave-related lockdown as against 1337 during the same period in 2019 (P < 0.0001). During the unlock period, 2659 such patients visited the hospital compared with 2122 in 2019 (P = 0.0145). During the second wave-related lockdown, there were 351 emergency patients compared with 526 patients in 2019 (P < 0.0001). Lens-induced glaucomas (50.4%) and neovascular glaucoma (20.6%) were the most common diagnoses during the first wave-related lockdown. During the unlock period, there was a greater proportion of neovascular glaucoma (P = 0.0123). The second wave-related lockdown had a greater proportion of phacolytic glaucomas (P = 0.005) and acute primary angle closure (P = 0.0397) patients. Conclusion: The study demonstrates that emergency glaucoma care was grossly underutilized by the people during the lockdowns. Trivial conditions like cataracts or retinal vascular diseases if not treated appropriately may progress to become emergencies in the future.

Automatic detection of glaucoma via fundus imaging and artificial intelligence: A review.

Glaucoma is a leading cause of irreversible vision impairment globally, and cases are continuously rising worldwide. Early detection is crucial, allowing timely intervention that can prevent further visual field loss. To detect glaucoma an examination of the optic nerve head via fundus imaging can be performed, at the center of which is the assessment of the optic cup and disc boundaries. Fundus imaging is noninvasive and low-cost; however, image examination relies on subjective, time-consuming, and costly expert assessments. A timely question to ask is: "Can artificial intelligence mimic glaucoma assessments made by experts?" Specifically, can artificial intelligence automatically find the boundaries of the optic cup and disc (providing a so-called segmented fundus image) and then use the segmented image to identify glaucoma with high accuracy? We conducted a comprehensive review on artificial intelligence-enabled glaucoma detection frameworks that produce and use segmented fundus images and summarized the advantages and disadvantages of such frameworks. We identified 36 relevant papers from 2011 to 2021 and 2 main approaches: 1) logical rule-based frameworks, based on a set of rules; and 2) machine learning/statistical modeling-based frameworks. We critically evaluated the state-of-art of the 2 approaches, identified gaps in the literature and pointed at areas for future research.

Clinical and demographic profile of patients less than 40 years of age presenting to glaucoma services at a tertiary care eye hospital in South India.

Purpose: To study the clinical and demographic profile of patients less than 40 years of age presenting to glaucoma services including the reasons for referral. Methods: Patients in the age group of 5 to 39 years, visiting the glaucoma clinic, who were either suspected to have glaucoma or who had been newly/previously diagnosed with glaucoma were included in the study. After informed written consent, basic demographic details of the participants including age, gender, education, socioeconomic status, and family history were obtained. A comprehensive ophthalmological evaluation was performed by glaucoma specialists. Results: The proportion of glaucoma in the study population (n = 384) was found to be 31.25%, and the incidence of glaucoma among new patients was found to be 11.9%. Among all glaucomas (n = 120), 44.2% of patients had secondary glaucomas, 27.5% had primary glaucomas, and 28.3% had congenital glaucomas. Also, 67.3% of all glaucoma patients were males. Newly diagnosed glaucoma patients presented with a mean intraocular pressure (IOP) of 32.9 mmHg and mild-moderate disc damage with a mean cup-disc ratio of 0.65. Nearly one-third of them had a presenting visual acuity worse than 5/60. The most common reason for referral was raised IOP. Univariate and multivariate analysis revealed that the odds of developing glaucoma were less in females (P = 0.04) and in patients with a higher standard of living index (P < 0.001). Conclusion: One-third of the patients had glaucoma and another one-third were suspects. Secondary glaucomas are more common than primary/congenital glaucomas. A comprehensive eye evaluation is a must, especially in those with predisposing factors.

Neuroprotection in glaucoma.

Neuroprotective therapies in glaucoma may play a role in preventing ischemia and oxidative damage that results in apoptosis of retinal ganglion cells and optic nerve damage. Although intraocular pressure (IOP) is the only known modifiable risk factor for glaucoma, disease progression commonly occurs despite IOP control, suggesting that factors other than IOP play a role in its pathogenesis and can potentially act as targets for neuroprotection. Factors including mediators of apoptosis, ischemic changes, poor ocular blood flow and neurotoxins have been hypothesized to play a role in glaucoma progression. Neuroprotective targets include glutamate-induced neurotoxicity, nitric oxidase synthetase, neurotropins, calcium channel receptors, free radicals, vascular insufficiency, the rho-kinase pathway, and more. Drugs related to these factors are being evaluated for their role in neuroprotection, although this area of investigation faces several challenges including limited evidence for these agents' efficacy in clinical studies. Additionally, while IOP-lowering therapies are considered neuroprotective as they generally slow the progress of glaucoma progression, they are limited by the extent of their effect beyond IOP control. The aim of this article is to review the current treatment options available for neuroprotection and to explore the drugs in the pipeline.

Assessment of Reasons for Presentation in New Primary Glaucoma Patients and Identification of Risk Factors for Late Presentation.

PURPOSE: To evaluate the reasons for seeking care among South Indian primary glaucoma patients and to determine the relationship of various patient characteristics to glaucoma severity at presentation. DESIGN: Cross-sectional study. PARTICIPANTS: One hundred sixty-one new primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) patients seeking treatment at a tertiary eye hospital. METHODS: After confirmation of diagnosis, participants' clinical information and their reported reasons for presentation were assessed. Data collected include age, gender, education, occupation, rural or urban residence, distance traveled to the hospital, method of transportation, need for an accompanying person, place of screening before referral or whether they came by themselves for testing. Advanced glaucoma was defined by a cup-to-disc ratio of 0.85 or higher in either eye. MAIN OUTCOME MEASURES: The primary outcomes were the various reasons for presentation. The secondary outcome was to determine whether a relationship existed between the patient characteristics mentioned above and presentation with advanced glaucoma. RESULTS: The mean age of the participants was 60.8 years. The primary reason for presentation was defective vision (55.2%) followed by routine ophthalmic evaluation (13%). Sixty-four patients (39.8%) showed advanced glaucoma in at least 1 eye at presentation. Unilateral blindness was noted in 18 patients (11.2%). The mean vertical cup-to-disc ratio was 0.66 (standard deviation [SD], ±0.16) in the better-seeing eye and 0.76 (SD, ±0.12) in the worse-seeing eye. The mean presenting intraocular pressure was 22.9 mmHg in POAG and 25.5 mmHg in PACG patients. Multivariate logistic regression analyses showed that people who are currently unemployed (P < 0.001; odds ratio [OR], 4.19; 95% confidence interval [CI], 1.95-8.99) and rural residence (P = 0.04; OR, 0.46; 95% CI, 0.21-0.99) had greater odds of demonstrating advanced glaucoma at presentation. Presentation with defective vision, older age, and education less than college graduation were associated with greater odds of showing advanced glaucoma in univariate analysis, but not in multivariate analyses. CONCLUSIONS: In a South Indian population, absence of work and rural residence was associated with advanced glaucoma at presentation. The population in whom these risk factors are common should be targeted for screening and outreach.

EffUnet-SpaGen: An Efficient and Spatial Generative Approach to Glaucoma Detection.

Current research in automated disease detection focuses on making algorithms "slimmer" reducing the need for large training datasets and accelerating recalibration for new data while achieving high accuracy. The development of slimmer models has become a hot research topic in medical imaging. In this work, we develop a two-phase model for glaucoma detection, identifying and exploiting a redundancy in fundus image data relating particularly to the geometry. We propose a novel algorithm for the cup and disc segmentation "EffUnet" with an efficient convolution block and combine this with an extended spatial generative approach for geometry modelling and classification, termed "SpaGen" We demonstrate the high accuracy achievable by EffUnet in detecting the optic disc and cup boundaries and show how our algorithm can be quickly trained with new data by recalibrating the EffUnet layer only. Our resulting glaucoma detection algorithm, "EffUnet-SpaGen", is optimized to significantly reduce the computational burden while at the same time surpassing the current state-of-art in glaucoma detection algorithms with AUROC 0.997 and 0.969 in the benchmark online datasets ORIGA and DRISHTI, respectively. Our algorithm also allows deformed areas of the optic rim to be displayed and investigated, providing explainability, which is crucial to successful adoption and implementation in clinical settings.

The Heritability of Primary Angle Closure Anatomic Traits and Predictors of Angle Closure in South Indian Siblings.

PURPOSE: To estimate the heritability of ocular biometric and anterior chamber morphologic parameters and to determine predictors of angle closure concordance in South Indian probands with angle closure and their siblings DESIGN: Prospective observational cohort study METHODS: Subjects received a standardized ophthalmic examination, A-scan ultrasonography, pachymetry, and anterior segment optical coherence tomography (ASOCT) imaging. Heritability was calculated using residual correlation coefficients adjusted for age, sex, and home setting. Concordant sibling pairs were defined as both proband and sibling with angle closure. Predictors of angle closure concordance among siblings were calculated using multivariable logistic regression models. RESULTS: A total of 345 sibling pairs participated. All anterior chamber parameters were highly heritable (P < .001 for all). Similarly, all iris parameters, axial length, lens thickness (LT), central corneal thickness, anterior lens curvature, lens vault (LV), spherical equivalent, and intraocular pressure were moderately to highly heritable (P < .004 for all). LV and LT were more heritable among concordant siblings (P < .05 for both). In contrast, ASOCT angle parameters had statistically insignificant heritability estimates. In multivariable analyses, siblings older than their probands were more likely to be concordant for angle closure (OR 1.05, 95% CI 1.01, 1.09; P = .02) and siblings with deeper anterior chamber depths (ACDs) compared to their proband were less likely to be concordant for angle closure (OR 0.74, 95% CI 0.64, 0.86; P < .001). CONCLUSIONS: Iris, anterior chamber, and lens parameters may be heritable whereas angle parameters were not. LT and LV may play important roles in the pathogenesis of angle closure. Siblings who are older or have a shallower ACD may need more careful disease monitoring.

Comparison of the corrected intraocular pressure by tonopachy with that of Goldmann applanation tonometry in normal and glaucomatous patients.

Purpose: To compare corrected intraocular pressure (IOP) by tonopachy with that of Goldmann applanation tonometry (GAT) in normal and glaucomatous patients. Methods: In this cross-sectional study, IOP and central corneal thickness (CCT) were measured in 426 eyes (213 normal eyes and 213 glaucomatous eyes) of 426 patients by tonopachy followed by GAT and ultrasound pachymetry. IOP was corrected for CCT by in-built formula in tonopachy and Ehlers correction factor for Goldmann tonometer. Limits of agreements were assessed using Bland-Altman plots. Intraclass correlation coefficient was calculated to estimate the absolute agreement between single and average measurements of IOP and CCT of tonopachy with that of Goldmann tonometer and ultrasound pachymetry respectively. Results: Mean corrected IOP measured with tonopachy and GAT in glaucomatous eyes was 17.63 ± 5.04 mmHg and 19.42 ± 5.83 mmHg, and in controls it was 13.4 ± 2.5 mmHg and 16.2 ± 3.1 mmHg, respectively. Limits of agreement ranged from -4.63 to +9.25 mmHg for total population (mean = 2.31), -6.01 to +9.59 mmHg (mean = 1.79) for glaucoma group and -2.99 to +8.65 mmHg (mean = 2.83) for controls. Intraclass correlation coefficient for IOP measurement between tonopachy and Goldmann tonometer was 0.84 for total population, 0.85 for glaucoma group, and 0.63 for controls, respectively. Conclusion: Corrected IOP obtained by tonopachy showed moderate agreement with GAT and it is more in glaucoma patients than controls. Thus, tonopachy can be used as a screening tool, but cannot replace GAT.

The Impact of Routinely Measuring IOP in Younger Adults to Screen for Glaucoma in a Large Eye Hospital.

PRECIS: Intraocular pressure (IOP) screening in adults 18 to 40 years of age identified 1 in 535 young adults with or at risk for developing glaucoma in India with a cost of about Indian rupee 596 (USD 8) per patient diagnosed. PURPOSE: The purpose of this study was to evaluate the outcomes of routine noncontact tonometry as a screening modality for glaucoma in young adults receiving an eye examination at Aravind Eye Hospital, Pondicherry, India. METHODS: Retrospective chart review of adults 18 to 40 years of age screened for IOP from November 2017 to June 2018. The diagnoses were determined by a glaucoma specialist using gonioscopy, dilated fundus examination, and occasionally, Humphrey Field Analyzer, and/or optical coherence tomography. Analyses include detection of glaucoma, ocular hypertension (OHT), angle closure, and calculation of the yield of this screening paradigm. RESULTS: A total of 28,369 younger adults were screened and 296 (1.05%) were referred to the glaucoma unit, 84 for an IOP >21 mm Hg and 208 for other reasons. The hypertensive group had a mean screening IOP of 29.3±8.4 mm Hg and the following diagnoses: OHT (19%), secondary raised IOP (14%), glaucoma (26%), angle closure (4%), healthy (11%) and need for further examination (26%). Fifty-five percent of those with glaucoma were previously undiagnosed. In comparison, the normotensive group had a mean IOP of 16±2.5 mm Hg and the following diagnoses: OHT (1%), glaucoma (5%), occludable angles (8%), healthy (47%) and need of further examination (33%). Nearly 40% of these patients with glaucoma were previously undiagnosed. CONCLUSIONS: One of every 535 young adults screened had both IOP >21 mm Hg and angle closure, OHT, secondary raised IOP or glaucoma. Given their young age and the potential to treat and delay progression, the benefits seem to outweigh the low cost of this screening.

Predictors of Short-Term Intraocular Pressure Change after Laser Peripheral Iridotomy: A Prospective Randomized Study.

PURPOSE: To describe short-term intraocular pressure (IOP) changes after laser peripheral iridotomy (LPI) and identify factors predicting IOP lowering. DESIGN: Multicenter, prospective randomized study. PARTICIPANTS: Four hundred fifty-five South Indian eyes of 455 participants 30 years of age or older with a diagnosis of primary angle-closure suspect (PACS), primary angle closure (PAC), or PAC glaucoma (PACG). METHODS: Participants were randomized to superior or nasal/temporal LPI. Multivariate regression models were used to determine preoperative features and LPI parameters associated with change in IOP from baseline to the 2-week postoperative examination. MAIN OUTCOME MEASURES: Change in IOP at 2 weeks after LPI compared with baseline. RESULTS: Among all treated eyes, 11.0% of eyes demonstrated a 20% or more decrease in IOP after LPI, whereas 19.6% demonstrated at least a 20% increase in IOP. Intraocular pressure changes occurring after LPI did not differ by LPI location (P > 0.5 for all comparisons). Although the anterior chamber angle widened after LPI (P < 0.001) and was classified as open after laser in most eyes (64% in all 4 quadrants), there was no significant association between gonioscopic angle opening and LPI-induced IOP change (P = 0.7). Linear regression analysis demonstrated more IOP lowering with higher baseline IOP (3.2 mmHg more lowering per 10-mmHg higher baseline IOP; 95% confidence interval [CI], 2.3-4.1 mmHg) and PAC/PACG diagnosis (1.4 mmHg more IOP lowering vs. PACS diagnosis; 95% CI, 0.2-2.6 mmHg) predicted a lower IOP after LPI. After multivariate adjustment, only higher baseline IOP predicted lower IOP after LPI (P < 0.001). Features not associated with IOP lowering included demographic, visual, and A-scan measures; baseline gonioscopic angle width; total laser energy; LPI area; and LPI location (P > 0.08 for all). Eyes with PAC/PACG, as compared with PACS, demonstrated more IOP lowering after LPI (1.2±1.7 mmHg vs. -0.4±1.0 mmHg; P < 0.001) after adjusting for baseline IOP. CONCLUSIONS: Neither LPI location nor degree of gonioscopic angle opening was associated with statistically significant change in IOP after LPI. Although significant IOP lowering after LPI was uncommon in the overall cohort, higher baseline IOP and PAC/PACG diagnosis predicted lower postoperative IOP.