Primary open-angle glaucoma (POAG), is a heritable common cause of blindness world-wide. To identify risk loci, we conduct a large multi-ethnic meta-analysis of genome-wide association studies on a total of 34,179 cases and 349,321 controls, identifying 44 previously unreported risk loci and confirming 83 loci that were previously known. The majority of loci have broadly consistent effects across European, Asian and African ancestries. Cross-ancestry data improve fine-mapping of causal variants for several loci. Integration of multiple lines of genetic evidence support the functional relevance of the identified POAG risk loci and highlight potential contributions of several genes to POAG pathogenesis, including SVEP1, RERE, VCAM1, ZNF638, CLIC5, SLC2A12, YAP1, MXRA5, and SMAD6. Several drug compounds targeting POAG risk genes may be potential glaucoma therapeutic candidates.

Janey Wiggs, Jonathan Haines and colleagues identify three new susceptibility loci for primary open-angle glaucoma. The association signals map near genes implicated in ocular development (FOXC1), neurodegeneration (ATXN2) and mitochondrial function (TXNRD2). Primary open-angle glaucoma (POAG) is a leading cause of blindness worldwide. To identify new susceptibility loci, we performed meta-analysis on genome-wide association study (GWAS) results from eight independent studies from the United States (3,853 cases and 33,480 controls) and investigated the most significantly associated SNPs in two Australian studies (1,252 cases and 2,592 controls), three European studies (875 cases and 4,107 controls) and a Singaporean Chinese study (1,037 cases and 2,543 controls). A meta-analysis of the top SNPs identified three new associated loci: rs35934224[T] in TXNRD2 (odds ratio (OR) = 0.78, P = 4.05 × 10−11) encoding a mitochondrial protein required for redox homeostasis; rs7137828[T] in ATXN2 (OR = 1.17, P = 8.73 × 10−10); and rs2745572[A] upstream of FOXC1 (OR = 1.17, P = 1.76 × 10−10). Using RT-PCR and immunohistochemistry, we show TXNRD2 and ATXN2 expression in retinal ganglion cells and the optic nerve head. These results identify new pathways underlying POAG susceptibility and suggest new targets for preventative therapies.

Oxidative stress may play a key role in the development of cognitive impairment. Long-term supplementation with vitamin E, a strong antioxidant, may provide cognitive benefits. The Women's Health Study is a randomized, double-blind, placebo-controlled trial of vitamin E supplementation (600 IU [alpha-tocopherol acetate], on alternate days) begun between 1992 and 1995 among 39 876 healthy US women. From 1998, 6377 women 65 years or older participated in a cognitive substudy. Three cognitive assessments of general cognition, verbal memory, and category fluency were administered by telephone at 2-year intervals. The primary outcome was a global composite score averaging performance on all tests. Repeated measures analyses were conducted to examine mean performance and mean differences in cognitive change, and logistic regression was used to estimate relative risks of substantial decline. There were no differences in global score between the vitamin E and placebo groups at the first assessment (5.6 years after randomization: mean difference, -0.01; 95% confidence interval [CI], -0.04 to 0.03) or at the last assessment (9.6 years of treatment: mean difference, 0.00; 95% CI, -0.04 to 0.04). Mean cognitive change over time was also similar in the vitamin E group compared with the placebo group for the global score (mean difference in change, 0.02; 95% CI, -0.01 to 0.05; P = .16). The relative risk of substantial decline in the global score in the vitamin E group compared with the placebo group was 0.92 (95% CI, 0.77 to 1.10). Long-term use of vitamin E supplements did not provide cognitive benefits among generally healthy older women.

The relation between dietary antioxidant intake and primary open-angle glaucoma risk was examined in participants aged over 40 years in the Nurses’ Health Study (n = 76,200) and the Health Professionals Follow-up Study (n = 40,284). They were followed biennially from 1980 and 1986, respectively, to 1996, during periods when they received an eye examination. Dietary intakes were measured repeatedly from 1980 in the Nurses’ Health Study and from 1986 in the Health Professionals Follow-up Study using validated food frequency questionnaires. The authors analyzed 474 self-reported glaucoma cases confirmed by medical chart review to have primary open-angle glaucoma with visual field loss. The authors used Cox proportional hazards models for cohort-specific multivariate analyses, and results were pooled using random effects models. The pooled multivariate rate ratios for primary open-angle glaucoma comparing the highest versus lowest quintile of cumulative updated intake were 1.17 (95% confidence interval (CI): 0.87, 1.58) for α-carotene, 1.10 (95% CI: 0.82, 1.48) for β-carotene, 0.95 (95% CI: 0.70, 1.29) for β–cryptoxanthin, 0.82 (95% CI: 0.60, 1.12) for lycopene, 0.92 (95% CI: 0.69, 1.24) for lutein/zeaxanthin, 1.05 (95% CI: 0.59, 1.89) for vitamin C, 0.97 (95% CI: 0.62, 1.52) for vitamin E, and 1.11 (95% CI: 0.82, 1.51) for vitamin A. In conclusion, the authors did not observe any strong associations between antioxidant consumption and the risk of primary open-angle glaucoma.