Preservation of vision after CaMKII-mediated protection of retinal ganglion cells.

Retinal ganglion cells (RGCs) are the sole output neurons that transmit visual information from the retina to the brain. Diverse insults and pathological states cause degeneration of RGC somas and axons leading to irreversible vision loss. A fundamental question is whether manipulation of a key regulator of RGC survival can protect RGCs from diverse insults and pathological states, and ultimately preserve vision. Here, we report that CaMKII-CREB signaling is compromised after excitotoxic injury to RGC somas or optic nerve injury to RGC axons, and reactivation of this pathway robustly protects RGCs from both injuries. CaMKII activity also promotes RGC survival in the normal retina. Further, reactivation of CaMKII protects RGCs in two glaucoma models where RGCs degenerate from elevated intraocular pressure or genetic deficiency. Last, CaMKII reactivation protects long-distance RGC axon projections in vivo and preserves visual function, from the retina to the visual cortex, and visually guided behavior.

The clinical utility of a glaucoma polygenic risk score in four population-based European-ancestry cohorts.

OBJECTIVE: We used a polygenic risk score (PRS) to identify high-risk groups for primary open-angle glaucoma (POAG) within population-based cohorts. DESIGN: Secondary analysis of four prospective population-based studies. PARTICIPANTS: We included four European-ancestry cohorts: the United States (US) based Nurses' Health Study (NHS), NHS2, and the Health Professionals Follow-up Study, and the Rotterdam Study (RS) in the Netherlands. The US cohorts included female nurses and male health professionals aged 55+ years. The RS included residents aged 45 years or older living in Rotterdam, the Netherlands. METHODS: PRS weights were estimated by applying the Lassosum method on imputed genotype and phenotype data from the UK-Biobank. This resulted in 144,020 variants, single nucleotide polymorphism (SNPs) and indels, with non-zero betas that we used to calculate a PRS in the target populations. Using multivariable Cox proportional hazard models, we estimated the relationship between the standardized PRS and relative risk for POAG. Additionally, POAG prediction was tested by calculating these models' concordance (Harrell's C-statistic). Finally, we assessed the association between PRS tertiles and glaucoma-related traits. MAIN OUTCOME MEASURES: The relative risk for POAG and Harrell's C-statistic (the equivalent of an area-under-the-curve for longitudinal models). RESULTS: Among 1,046 cases and 38,809‬ controls, the relative risk (95% confidence interval) for POAG for participants in the highest PRS quintile was 3.99 (3.08, 5.18) in the US cohorts, and 4.89 (2.93, 8.17) in the Rotterdam Study, compared with participants with median genetic risk (3rd quintile). In restricted cubic spline analyses, the relation between continuous PRS and POAG risk increased exponentially in the US and Rotterdam cohorts (Pspline<0.05). Combining age, sex, intraocular pressure >25 mmHg, and family history resulted in a meta-analyzed concordance of 0.75 (0.73, 0.75). Adding the PRS to this model improved the concordance to 0.82 (0.80, 0.84). In a meta-analysis of all cohorts, cases in the highest tertile had a larger cup-disc ratio at diagnosis, by 0.11 (0.07, 0.15), and a 2.07-fold increased risk of requiring glaucoma surgery (1.19, 3.60). CONCLUSIONS: Incorporating a PRS into a POAG predictive model improves identification concordance from 0.75 up to 0.82, supporting its potential for guiding more cost-effective screening strategies.

Recent developments of telemedicine in glaucoma.

PURPOSE OF REVIEW: Telemedicine has an increasingly significant role in the fields of ophthalmology and glaucoma. This review covers recent advancements in the development and optimization of teleglaucoma techniques and applications. RECENT FINDINGS: Glaucoma monitoring and diagnosis via remote tonometry, perimetry, and fundus imaging have become a possibility based on recent developments. Many applications work in combination with smart devices, virtual reality, and artificial intelligence and have been tested in patient populations against conventional "reference-standard" measurement tools, demonstrating promising results. Of note, there is still much progress to be made in teleglaucoma and telemedicine at large, such as accessibility to internet, broadband, and smart devices, application affordability, and reimbursement for remote services. However, continued development and optimization of these applications suggest that the implementation of remote monitoring will be a mainstay for glaucoma patient care. SUMMARY: Especially since the beginning of the COVID-19 pandemic, remote patient care has taken on an important role in medicine and ophthalmology. Remote versions of tonometry, perimetry, and fundus imaging may allow for a more patient-centered and accessible future for glaucoma care.

Genetic variation affects morphological retinal phenotypes extracted from UK Biobank optical coherence tomography images.

Optical Coherence Tomography (OCT) enables non-invasive imaging of the retina and is used to diagnose and manage ophthalmic diseases including glaucoma. We present the first large-scale genome-wide association study of inner retinal morphology using phenotypes derived from OCT images of 31,434 UK Biobank participants. We identify 46 loci associated with thickness of the retinal nerve fibre layer or ganglion cell inner plexiform layer. Only one of these loci has been associated with glaucoma, and despite its clear role as a biomarker for the disease, Mendelian randomisation does not support inner retinal thickness being on the same genetic causal pathway as glaucoma. We extracted overall retinal thickness at the fovea, representative of foveal hypoplasia, with which three of the 46 SNPs were associated. We additionally associate these three loci with visual acuity. In contrast to the Mendelian causes of severe foveal hypoplasia, our results suggest a spectrum of foveal hypoplasia, in part genetically determined, with consequences on visual function.

Correction: Genetic variation affects morphological retinal phenotypes extracted from UK Biobank optical coherence tomography images.

[This corrects the article DOI: 10.1371/journal.pgen.1009497.].

Genome-wide polygenic risk score for retinopathy of type 2 diabetes.

Diabetic retinopathy (DR) is a common consequence in type 2 diabetes (T2D) and a leading cause of blindness in working-age adults. Yet, its genetic predisposition is largely unknown. Here, we examined the polygenic architecture underlying DR by deriving and assessing a genome-wide polygenic risk score (PRS) for DR. We evaluated the PRS in 6079 individuals with T2D of European, Hispanic, African and other ancestries from a large-scale multi-ethnic biobank. Main outcomes were PRS association with DR diagnosis, symptoms and complications, and time to diagnosis, and transferability to non-European ancestries. We observed that PRS was significantly associated with DR. A standard deviation increase in PRS was accompanied by an adjusted odds ratio (OR) of 1.12 [95% confidence interval (CI) 1.04-1.20; P = 0.001] for DR diagnosis. When stratified by ancestry, PRS was associated with the highest OR in European ancestry (OR = 1.22, 95% CI 1.02-1.41; P = 0.049), followed by African (OR = 1.15, 95% CI 1.03-1.28; P = 0.028) and Hispanic ancestries (OR = 1.10, 95% CI 1.00-1.10; P = 0.050). Individuals in the top PRS decile had a 1.8-fold elevated risk for DR versus the bottom decile (P = 0.002). Among individuals without DR diagnosis, the top PRS decile had more DR symptoms than the bottom decile (P = 0.008). The PRS was associated with retinal hemorrhage (OR = 1.44, 95% CI 1.03-2.02; P = 0.03) and earlier DR presentation (10% probability of DR by 4 years in the top PRS decile versus 8 years in the bottom decile). These results establish the significant polygenic underpinnings of DR and indicate the need for more diverse ancestries in biobanks to develop multi-ancestral PRS.

Long-term Alcohol Consumption and Risk of Exfoliation Glaucoma or Glaucoma Suspect Status among United States Health Professionals.

PURPOSE: To assess the association between intakes of total alcohol and individual alcoholic beverages and the incidence of exfoliation glaucoma/glaucoma suspect (XFG/XFGS) status. DESIGN: Prospective cohort study. PARTICIPANTS: A total of 195 408 participants in the Nurses' Health Study (1980-2018), the Health Professionals Follow-up Study (1986-2018), and the Nurses' Health Study II (1991-2019) were followed biennially. Eligible participants at each 2-year risk period were ≧ 40 years and free of XFG/XFGS status with available data on diet and ophthalmic examination findings. METHODS: Cumulatively averaged total (primary exposure) and individual alcoholic beverage (beer, wine, and liquor) intakes from validated dietary information every 2-4 years. MAIN OUTCOME MEASURES: Confirmed incident XFG/XFGS status using medical records. We used per-eye Cox proportional hazards models, accounting for intereye correlations, to estimate multivariate-adjusted relative risks (MVRRs) and 95% confidence intervals (CIs). RESULTS: During 6 877 823 eye-years of follow-up, 705 eyes with XFG/XFGS status were documented. Greater total alcohol consumption was associated significantly with higher XFG/XFGS status risk: the MVRR for XFG/XFGS status for cumulatively averaged alcohol consumption of ≧15 g/day or more versus nondrinking was 1.55 (95% CI, 1.17-2.07; P = 0.02 for trend). Long- and short-term alcohol intake was associated significantly with XFG/XFGS status risk, with the strongest associations with cumulatively averaged alcohol intake as of 4 years before diagnosis (MVRR ≥ 15 g/day vs. nondrinking, 1.65; 95% CI, 1.25-2.18; P = 0.002 for trend). Compared with nondrinkers, consuming ≧ 3.6 drinks of beer, wine, or liquor per week was associated with the following MVRRs for XFG/XFGS status: 1.26 (95% CI, 0.89-1.77; P = 0.40 for trend), 1.30 (95% CI, 1.00-1.68; P = 0.15 for trend), and 1.46 (95% CI, 1.15-1.85; P = 0.01 for trend), respectively. We did not observe interactions by age, latitude, residential tier, or intakes of folate or vitamin A (P > 0.40 for interaction); however, the association between alcohol and XFG/XFGS status was suggestively stronger for those without a family history of glaucoma (P = 0.10 for interaction). CONCLUSIONS: Long-term alcohol consumption was associated with a higher risk of XFG/XFGS status. Our findings provide further clues regarding the XFG/XFGS etiology.

Effect of Low-Fat Dietary Modification on Incident Open-Angle Glaucoma.

PURPOSE: We tested whether dietary modification (DM) altered the risk for incident primary open-angle glaucoma (POAG). DESIGN: Secondary analysis of a randomized intervention trial. PARTICIPANTS: We linked Medicare claims data to 45 203 women in the Women's Health Initiative Dietary Modification Trial, of which 23 776 participants were enrolled in fee-for-service Medicare Part B and had physician claims. METHODS: Women were randomized to follow either DM (a low-fat diet, with increased vegetable, fruit, and grain intake) or their usual diet without modification. Nine thousand three hundred forty women were randomized to the DM intervention, whereas 13 877 women were randomized to the control group. Our analyses were based on an intention-to-treat design, with a follow-up to the end of continuous Medicare coverage, death, or the last claims date (12/31/2018), whichever occurred first. Primary open-angle glaucoma was defined as the first claim with the International Classification of Diseases, Ninth or Tenth Revision, codes. Dietary data were assessed using a food frequency questionnaire. MAIN OUTCOME MEASURES: We used Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for risk of POAG. Subgroup analyses were performed with P values for interaction. RESULTS: After exclusion of women with Medicare-derived glaucoma before randomization, the final analysis included 23 217 women (mean age, 64.4 ± 5.8 years). Baseline characteristics were balanced between the intervention and control groups. Primary open-angle glaucoma incidence was 11.1 per 1000 woman-years (mean follow-up, 11.6 ± 7.4 years; mean DM duration, 5.2 ± 3.2 years). We found no overall benefit of DM in reducing incident POAG (HR, 1.04; 95% CI, 0.96-1.12). Race and participant age did not modify this relation (P = 0.08 and P = 0.24 for interaction, respectively). In further analysis of baseline nutrient and food intake stratified by quartile groups, risk of open-angle glaucoma (OAG) in DM participants in the lowest quartile group for percentage calories (kilocalories) from total fat (33.8 or lower) was increased (HR, 1.22; 95% CI, 1.05-1.41; P = 0.007 for interaction). CONCLUSIONS: Analysis suggests that DM in participants in the lowest quartile group for percentage calories from total fat at baseline increased the risk of incident OAG among women regardless of age or race. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Mitochondrial TXNRD2 and ME3 Genetic Risk Scores Are Associated with Specific Primary Open-Angle Glaucoma Phenotypes.

PURPOSE: Genetic variants in regions that include the mitochondrial genes thioredoxin reductase 2 (TXNRD2) and malic enzyme 3 (ME3) are associated with primary open-angle glaucoma (POAG) in genome-wide association studies (GWASs). To assess their clinical impact, we investigated whether TXNRD2 and ME3 genetic risk scores (GRSs) are associated with specific glaucoma phenotypes. DESIGN: Cross-sectional study. PARTICIPANTS: A total of 2617 patients with POAG and 2634 control participants from the National Eye Institute Glaucoma Human Genetics Collaboration Hereditable Overall Operational Database (NEIGHBORHOOD) consortium. METHODS: All POAG-associated single nucleotide polymorphisms (SNPs) in the TXNRD2 and ME3 loci were identified using GWAS data (P < 0.05). Of these, 20 TXNRD2 and 24 ME3 SNPs were selected after adjusting for linkage disequilibrium. The correlation between SNP effect size and gene expression levels was investigated using the Gene-Tissue Expression database. Genetic risk scores were constructed for each individual using the unweighted sum of TXNRD2, ME3, and TXNRD2 + ME3 combined risk alleles. Age- and sex-adjusted odds ratios (ORs) for POAG diagnosis were calculated per decile for each GRS. Additionally, the clinical features of patients with POAG in the top 1%, 5%, and 10% of each GRS were compared with those in the bottom 1%, 5%, and 10%, respectively. MAIN OUTCOME MEASURES: Primary open-angle glaucoma OR per GRS decile, maximum treated intraocular pressure (IOP), and prevalence of paracentral visual field loss among patients with POAG with high versus low GRSs. RESULTS: A larger SNP effect size strongly correlated with higher TXNRD2 and lower ME3 expression levels (r = 0.95 and r = -0.97, respectively; P < 0.05 for both). Individuals in decile 10 of the TXNRD2 + ME3 GRS had the highest odds of POAG diagnosis (OR, 1.79 compared with decile 1; 95% confidence interval, 1.39-2.30; P < 0.001). Patients with POAG in the top 1% of the TXNRD2 GRS showed higher mean maximum treated IOP compared with the bottom 1% (19.9 mmHg vs. 15.6 mmHg; adjusted P = 0.03). Patients with POAG in the top 1% of the ME3 and TXNRD2 + ME3 GRS showed a higher prevalence of paracentral field loss than the bottom 1% (72.7% vs. 14.3% for ME3 GRS and 88.9% vs. 33.3% for TXNRD2+ME3 GRS; adjusted P = 0.03 for both). CONCLUSIONS: Patients with POAG with higher TXNRD2 and ME3 GRSs showed higher treated IOP and a greater prevalence of paracentral field loss. Functional studies exploring how these variants impact mitochondrial function in patients with glaucoma are warranted. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

The Association of Physical Activity with Glaucoma and Related Traits in the UK Biobank.

PURPOSE: To examine the association of physical activity (PA) with glaucoma and related traits, to assess whether genetic predisposition to glaucoma modified these associations, and to probe causal relationships using Mendelian randomization (MR). DESIGN: Cross-sectional observational and gene-environment interaction analyses in the UK Biobank. Two-sample MR experiments using summary statistics from large genetic consortia. PARTICIPANTS: UK Biobank participants with data on self-reported or accelerometer-derived PA and intraocular pressure (IOP; n = 94 206 and n = 27 777, respectively), macular inner retinal OCT measurements (n = 36 274 and n = 9991, respectively), and glaucoma status (n = 86 803 and n = 23 556, respectively). METHODS: We evaluated multivariable-adjusted associations of self-reported (International Physical Activity Questionnaire) and accelerometer-derived PA with IOP and macular inner retinal OCT parameters using linear regression and with glaucoma status using logistic regression. For all outcomes, we examined gene-PA interactions using a polygenic risk score (PRS) that combined the effects of 2673 genetic variants associated with glaucoma. MAIN OUTCOME MEASURES: Intraocular pressure, macular retinal nerve fiber layer (mRNFL) thickness, macular ganglion cell-inner plexiform layer (mGCIPL) thickness, and glaucoma status. RESULTS: In multivariable-adjusted regression models, we found no association of PA level or time spent in PA with glaucoma status. Higher overall levels and greater time spent in higher levels of both self-reported and accelerometer-derived PA were associated positively with thicker mGCIPL (P < 0.001 for trend for each). Compared with the lowest quartile of PA, participants in the highest quartiles of accelerometer-derived moderate- and vigorous-intensity PA showed a thicker mGCIPL by +0.57 µm (P < 0.001) and +0.42 µm (P = 0.005). No association was found with mRNFL thickness. High overall level of self-reported PA was associated with a modestly higher IOP of +0.08 mmHg (P = 0.01), but this was not replicated in the accelerometry data. No associations were modified by a glaucoma PRS, and MR analyses did not support a causal relationship between PA and any glaucoma-related outcome. CONCLUSIONS: Higher overall PA level and greater time spent in moderate and vigorous PA were not associated with glaucoma status but were associated with thicker mGCIPL. Associations with IOP were modest and inconsistent. Despite the well-documented acute reduction in IOP after PA, we found no evidence that high levels of habitual PA are associated with glaucoma status or IOP in the general population. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Estrogen dysregulation, intraocular pressure, and glaucoma risk.

Characterized by optic nerve atrophy due to retinal ganglion cell (RGC) death, glaucoma is the leading cause of irreversible blindness worldwide. Of the major risk factors for glaucoma (age, ocular hypertension, and genetics), only elevated intraocular pressure (IOP) is modifiable, which is largely regulated by aqueous humor outflow through the trabecular meshwork. Glucocorticoids such as dexamethasone have long been known to elevate IOP and lead to glaucoma. However, several recent studies have reported that steroid hormone estrogen levels inversely correlate with glaucoma risk, and that variants in estrogen signaling genes have been associated with glaucoma. As a result, estrogen dysregulation may contribute to glaucoma pathogenesis, and estrogen signaling may protect against glaucoma. The mechanism for estrogen-related protection against glaucoma is not completely understood but likely involves both regulation of IOP homeostasis and neuroprotection of RGCs. Based upon its known activities, estrogen signaling may promote IOP homeostasis by affecting extracellular matrix turnover, focal adhesion assembly, actin stress fiber formation, mechanosensation, and nitric oxide production. In addition, estrogen receptors in the RGCs may mediate neuroprotective functions. As a result, the estrogen signaling pathway may offer a therapeutic target for both IOP control and neuroprotection. This review examines the evidence for a relationship between estrogen and IOP and explores the possible mechanisms by which estrogen maintains IOP homeostasis.

Machine-Identified Patterns of Visual Field Loss and an Association with Rapid Progression in the Ocular Hypertension Treatment Study.

PURPOSE: To identify patterns of visual field (VF) loss based on unsupervised machine learning and to identify patterns that are associated with rapid progression. DESIGN: Cross-sectional and longitudinal study. PARTICIPANTS: A total of 2231 abnormal VFs from 205 eyes of 176 Ocular Hypertension Treatment Study (OHTS) participants followed over approximately 16 years. METHODS: Visual fields were assessed by an unsupervised deep archetypal analysis algorithm and an OHTS-certified VF reader to identify prevalent patterns of VF loss. Machine-identified patterns of glaucoma damage were compared against those patterns previously identified (expert-identified) in the OHTS in 2003. Based on the longitudinal VFs of each eye, VF loss patterns that were strongly associated with rapid glaucoma progression were identified. MAIN OUTCOME MEASURES: Machine-expert correspondence and type of patterns of VF loss associated with rapid progression. RESULTS: The average VF mean deviation (MD) at conversion to glaucoma was -2.7 decibels (dB) (standard deviation [SD] = 2.4 dB), whereas the average MD of the eyes at the last visit was -5.2 dB (SD = 5.5 dB). Fifty out of 205 eyes had MD rate of -1 dB/year or worse and were considered rapid progressors. Eighteen machine-identified patterns of VF loss were compared with expert-identified patterns, in which 13 patterns of VF loss were similar. The most prevalent expert-identified patterns included partial arcuate, paracentral, and nasal step defects, and the most prevalent machine-identified patterns included temporal wedge, partial arcuate, nasal step, and paracentral VF defects. One of the machine-identified patterns of VF loss predicted future rapid VF progression after adjustment for age, sex, and initial MD. CONCLUSIONS: An automated machine learning system can identify patterns of VF loss and could provide objective and reproducible nomenclature for characterizing early signs of visual defects and rapid progression in patients with glaucoma.

Unsupervised Machine Learning Shows Change in Visual Field Loss in the Idiopathic Intracranial Hypertension Treatment Trial.

PURPOSE: We previously reported that archetypal analysis (AA), a type of unsupervised machine learning, identified and quantified patterns of visual field (VF) loss in idiopathic intracranial hypertension (IIH), referred to as archetypes (ATs). We assessed whether AT weight changes over time are consistent with changes in conventional global indices, whether visual outcome or treatment effects are associated with select AT, and whether AA reveals residual VF defects in eyes deemed normal after treatment. DESIGN: Analysis of data collected from a randomized controlled trial. PARTICIPANTS: Two thousand eight hundred sixty-two VFs obtained from 165 participants during the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT). METHODS: We applied a 14-AT model derived from IIHTT VFs. We examined changes in individual AT weights over time for all study eyes and evaluated differences between treatment groups. We created an AT change score to assess overall VF change from baseline. We tested threshold baseline AT weights for association with VF outcome and treatment effect at 6 months. We determined the abnormal ATs with meaningful weight at outcome for VFs with a mean deviation (MD) of -2.00 dB or more. MAIN OUTCOME MEASURES: Individual AT weighting coefficients and MD. RESULTS: Archetype 1 (a normal VF pattern) showed the greatest weight change for all study eyes, increasing from 11.9% (interquartile range [IQR], 0.44%-24.1%) at baseline to 31.2% (IQR, 16.0%-45.5%) at outcome (P < 0.001). Archetype 1 weight change (r = 0.795; P < 0.001) and a global score of AT change (r = 0.988; P < 0.001) correlated strongly with MD change. Study eyes with baseline AT2 (a mild diffuse VF loss pattern) weight of 44% or more (≥ 1 standard deviation more than the mean) showed higher AT2 weights at outcome than those with AT2 weight of < 44% at baseline (P < 0.001). Only the latter group showed a significant acetazolamide treatment effect. Archetypal analysis revealed residual VF loss patterns, most frequently representing mild diffuse loss and an enlarged blind spot in 64 of 66 study eyes with MD of -2.00 dB or more at outcome. CONCLUSIONS: Archetypal analysis provides a quantitative approach to monitoring VF changes in IIH. Baseline AT features may be associated with treatment response and VF outcome. Archetypal analysis uncovers residual VF defects not otherwise revealed by MD.

Alcohol, Intraocular Pressure, and Open-Angle Glaucoma: A Systematic Review and Meta-analysis.

TOPIC: This systematic review and meta-analysis summarizes the existing evidence for the association of alcohol use with intraocular pressure (IOP) and open-angle glaucoma (OAG). CLINICAL RELEVANCE: Understanding and quantifying these associations may aid clinical guidelines or treatment strategies and shed light on disease pathogenesis. The role of alcohol, a modifiable factor, in determining IOP and OAG risk also may be of interest from an individual or public health perspective. METHODS: The study protocol was preregistered in the Open Science Framework Registries (https://osf.io/z7yeg). Eligible articles (as of May 14, 2021) from 3 databases (PubMed, Embase, Scopus) were independently screened and quality assessed by 2 reviewers. All case-control, cross-sectional, and cohort studies reporting a quantitative effect estimate and 95% confidence interval (CI) for the association between alcohol use and either IOP or OAG were included. The evidence for the associations with both IOP and OAG was qualitatively summarized. Effect estimates for the association with OAG were pooled using random effects meta-analysis. Studies not meeting formal inclusion criteria for systematic review, but with pertinent results, were also appraised and discussed. Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. RESULTS: Thirty-four studies were included in the systematic review. Evidence from 10 studies reporting an association with IOP suggests that habitual alcohol use is associated with higher IOP and prevalence of ocular hypertension (IOP > 21 mmHg), although absolute effect sizes were small. Eleven of 26 studies, comprising 173 058 participants, that tested for an association with OAG met inclusion criteria for meta-analysis. Pooled effect estimates indicated a positive association between any use of alcohol and OAG (1.18; 95% confidence interval [CI], 1.02-1.36; P = 0.03; I2 = 40.5%), with similar estimates for both prevalent and incident OAG. The overall GRADE certainty of evidence was very low. CONCLUSIONS: Although this meta-analysis suggests a harmful association between alcohol use and OAG, our results should be interpreted cautiously given the weakness and heterogeneity of the underlying evidence base, the small absolute effect size, and the borderline statistical significance. Nonetheless, these findings may be clinically relevant, and future research should focus on improving the quality of evidence.

The Association between Serum Lipids and Intraocular Pressure in 2 Large United Kingdom Cohorts.

PURPOSE: Serum lipids are modifiable, routinely collected blood test features associated with cardiovascular health. We examined the association of commonly collected serum lipid measures (total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], and triglycerides) with intraocular pressure (IOP). DESIGN: Cross-sectional study in the UK Biobank and European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk cohorts. PARTICIPANTS: We included 94 323 participants from the UK Biobank (mean age, 57 years) and 6230 participants from the EPIC-Norfolk (mean age, 68 years) cohorts with data on TC, HDL-C, LDL-C, and triglycerides collected between 2006 and 2009. METHODS: Multivariate linear regression adjusting for demographic, lifestyle, anthropometric, medical, and ophthalmic covariables was used to examine the associations of serum lipids with corneal-compensated IOP (IOPcc). MAIN OUTCOME MEASURES: Corneal-compensated IOP. RESULTS: Higher levels of TC, HDL-C, and LDL-C were associated independently with higher IOPcc in both cohorts after adjustment for key demographic, medical, and lifestyle factors. For each 1-standard deviation increase in TC, HDL-C, and LDL-C, IOPcc was higher by 0.09 mmHg (95% confidence interval [CI], 0.06-0.11 mmHg; P < 0.001), 0.11 mmHg (95% CI, 0.08-0.13 mmHg; P < 0.001), and 0.07 mmHg (95% CI, 0.05-0.09 mmHg; P < 0.001), respectively, in the UK Biobank cohort. In the EPIC-Norfolk cohort, each 1-standard deviation increase in TC, HDL-C, and LDL-C was associated with a higher IOPcc by 0.19 mmHg (95% CI, 0.07-0.31 mmHg; P = 0.001), 0.14 mmHg (95% CI, 0.03-0.25 mmHg; P = 0.016), and 0.17 mmHg (95% CI, 0.06-0.29 mmHg; P = 0.003). An inverse association between triglyceride levels and IOP in the UK Biobank (-0.05 mmHg; 95% CI, -0.08 to -0.03; P < 0.001) was not replicated in the EPIC-Norfolk cohort (P = 0.30). CONCLUSIONS: Our findings suggest that serum TC, HDL-C, and LDL-C are associated positively with IOP in 2 United Kingdom cohorts and that triglyceride levels may be associated negatively. Future research is required to assess whether these associations are causal in nature.

Genetic pleiotropy of ERCC6 loss-of-function and deleterious missense variants links retinal dystrophy, arrhythmia, and immunodeficiency in diverse ancestries.

Biobanks with exomes linked to electronic health records (EHRs) enable the study of genetic pleiotropy between rare variants and seemingly disparate diseases. We performed robust clinical phenotyping of rare, putatively deleterious variants (loss-of-function [LoF] and deleterious missense variants) in ERCC6, a gene implicated in inherited retinal disease. We analyzed 213,084 exomes, along with a targeted set of retinal, cardiac, and immune phenotypes from two large-scale EHR-linked biobanks. In the primary analysis, a burden of deleterious variants in ERCC6 was strongly associated with (1) retinal disorders; (2) cardiac and electrocardiogram perturbations; and (3) immunodeficiency and decreased immunoglobulin levels. Meta-analysis of results from the BioMe Biobank and UK Biobank showed a significant association of deleterious ERCC6 burden with retinal dystrophy (odds ratio [OR] = 2.6, 95% confidence interval [CI]: 1.5-4.6; p = 8.7 × 10-4 ), atypical atrial flutter (OR = 3.5, 95% CI: 1.9-6.5; p = 6.2 × 10-5 ), arrhythmia (OR = 1.5, 95% CI: 1.2-2.0; p = 2.7 × 10-3 ), and lymphocyte immunodeficiency (OR = 3.8, 95% CI: 2.1-6.8; p = 5.0 × 10-6 ). Carriers of ERCC6 LoF variants who lacked a diagnosis of these conditions exhibited increased symptoms, indicating underdiagnosis. These results reveal a unique genetic link among retinal, cardiac, and immune disorders and underscore the value of EHR-linked biobanks in assessing the full clinical profile of carriers of rare variants.

Non-Synonymous variants in premelanosome protein (PMEL) cause ocular pigment dispersion and pigmentary glaucoma.

Pigmentary glaucoma (PG) is a common glaucoma subtype that results from release of pigment from the iris, called pigment dispersion syndrome (PDS), and its deposition throughout the anterior chamber of the eye. Although PG has a substantial heritable component, no causative genes have yet been identified. We used whole exome sequencing of two independent pedigrees to identify two premelanosome protein (PMEL) variants associated with heritable PDS/PG. PMEL encodes a key component of the melanosome, the organelle essential for melanin synthesis, storage and transport. Targeted screening of PMEL in three independent cohorts (n = 394) identified seven additional PDS/PG-associated non-synonymous variants. Five of the nine variants exhibited defective processing of the PMEL protein. In addition, analysis of PDS/PG-associated PMEL variants expressed in HeLa cells revealed structural changes to pseudomelanosomes indicating altered amyloid fibril formation in five of the nine variants. Introduction of 11-base pair deletions to the homologous pmela in zebrafish by the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 method caused profound pigmentation defects and enlarged anterior segments in the eye, further supporting PMEL's role in ocular pigmentation and function. Taken together, these data support a model in which missense PMEL variants represent dominant negative mutations that impair the ability of PMEL to form functional amyloid fibrils. While PMEL mutations have previously been shown to cause pigmentation and ocular defects in animals, this research is the first report of mutations in PMEL causing human disease.

Intraocular Pressure, Glaucoma, and Dietary Caffeine Consumption: A Gene-Diet Interaction Study from the UK Biobank.

PURPOSE: We examined the association of habitual caffeine intake with intraocular pressure (IOP) and glaucoma and whether genetic predisposition to higher IOP modified these associations. We also assessed whether genetic predisposition to higher coffee consumption was related to IOP. DESIGN: Cross-sectional study in the UK Biobank. PARTICIPANTS: We included 121 374 participants (baseline ages, 39-73 years) with data on coffee and tea intake (collected 2006-2010) and corneal-compensated IOP measurements in 2009. In a subset of 77 906 participants with up to 5 web-based 24-hour-recall food frequency questionnaires (2009-2012), we evaluated total caffeine intake. We also assessed the same relationships with glaucoma (9286 cases and 189 763 controls). METHODS: We evaluated multivariable-adjusted associations with IOP using linear regression and with glaucoma using logistic regression. For both outcomes, we examined gene-diet interactions using a polygenic risk score (PRS) that combined the effects of 111 genetic variants associated with IOP. We also performed Mendelian randomization using 8 genetic variants associated with coffee intake to assess potential causal effects of coffee consumption on IOP. MAIN OUTCOME MEASURES: Intraocular pressure and glaucoma. RESULTS: Mendelian randomization analysis did not support a causal effect of coffee drinking on IOP (P > 0.1). Greater caffeine intake was associated weakly with lower IOP: the highest (≥232 mg/day) versus lowest (<87 mg/day) caffeine consumption was associated with a 0.10-mmHg lower IOP (Ptrend = 0.01). However, the IOP PRS modified this association: among those in the highest IOP PRS quartile, consuming > 480 mg/day versus < 80 mg/day was associated with a 0.35-mmHg higher IOP (Pinteraction = 0.01). The relationship between caffeine intake and glaucoma was null (P ≥ 0.1). However, the IOP PRS also modified this relationship: compared with those in the lowest IOP PRS quartile consuming no caffeine, those in the highest IOP PRS quartile consuming ≥ 321 mg/day showed a 3.90-fold higher glaucoma prevalence (Pinteraction = 0.0003). CONCLUSIONS: Habitual caffeine consumption was associated weakly with lower IOP, and the association between caffeine consumption and glaucoma was null. However, among participants with the strongest genetic predisposition to elevated IOP, greater caffeine consumption was associated with higher IOP and higher glaucoma prevalence.

Identification of Estrogen Signaling in a Prioritization Study of Intraocular Pressure-Associated Genes.

Elevated intraocular pressure (IOP) is the only modifiable risk factor for primary open-angle glaucoma (POAG). Herein we sought to prioritize a set of previously identified IOP-associated genes using novel and previously published datasets. We identified several genes for future study, including several involved in cytoskeletal/extracellular matrix reorganization, cell adhesion, angiogenesis, and TGF-ß signaling. Our differential correlation analysis of IOP-associated genes identified 295 pairs of 201 genes with differential correlation. Pathway analysis identified ß-estradiol as the top upstream regulator of these genes with ESR1 mediating 25 interactions. Several genes (i.e., EFEMP1, FOXC1, and SPTBN1) regulated by ß-estradiol/ESR1 were highly expressed in non-glaucomatous human trabecular meshwork (TM) or Schlemm's canal (SC) cells and specifically expressed in TM/SC cell clusters defined by single-cell RNA-sequencing. We confirmed ESR1 gene and protein expression in human TM cells and TM/SC tissue with quantitative real-time PCR and immunofluorescence, respectively. 17ß-estradiol was identified in bovine, porcine, and human aqueous humor (AH) using ELISA. In conclusion, we have identified estrogen receptor signaling as a key modulator of several IOP-associated genes. The expression of ESR1 and these IOP-associated genes in TM/SC tissue and the presence of 17ß-estradiol in AH supports a role for estrogen signaling in IOP regulation.

Genome-wide association study identifies seven novel susceptibility loci for primary open-angle glaucoma.

Primary open-angle glaucoma (POAG) is the leading cause of irreversible blindness worldwide for which 15 disease-associated loci had been discovered. Among them, only 5 loci have been associated with POAG in Asians. We carried out a genome-wide association study and a replication study that included a total of 7378 POAG cases and 36 385 controls from a Japanese population. After combining the genome-wide association study and the two replication sets, we identified 11 POAG-associated loci, including 4 known (CDKN2B-AS1, ABCA1, SIX6 and AFAP1) and 7 novel loci (FNDC3B, ANKRD55-MAP3K1, LMX1B, LHPP, HMGA2, MEIS2 and LOXL1) at a genome-wide significance level (P < 5.0×10-8), bringing the total number of POAG-susceptibility loci to 22. The 7 novel variants were subsequently evaluated in a multiethnic population comprising non-Japanese East Asians (1008 cases, 591 controls), Europeans (5008 cases, 35 472 controls) and Africans (2341 cases, 2037 controls). The candidate genes located within the new loci were related to ocular development (LMX1B, HMGA2 and MAP3K1) and glaucoma-related phenotypes (FNDC3B, LMX1B and LOXL1). Pathway analysis suggested epidermal growth factor receptor signaling might be involved in POAG pathogenesis. Genetic correlation analysis revealed the relationships between POAG and systemic diseases, including type 2 diabetes and cardiovascular diseases. These results improve our understanding of the genetic factors that affect the risk of developing POAG and provide new insight into the genetic architecture of POAG in Asians.