Objective To describe the baseline characteristics of the Primary Open-Angle African-American Glaucoma Genetics (POAAGG) study cohort, the largest African-American primary open-angle glaucoma (POAG) population recruited at a single institution (University of Pennsylvania, Department of Ophthalmology, Scheie Eye Institute) to date. Design Population-based, cross-sectional, case-control study. Participants 2,520 African-American subjects 35 years and older, recruited from the greater Philadelphia, Pennsylvania area. Methods Each subject underwent a detailed interview and eye examination. The interview assessed demographic, behavioral, medical, and ocular risk factors. Current zip codes surrounding the University of Pennsylvania were recorded and United States census data were queried to infer socioeconomic status. The eye exam included measurement of visual acuity and intraocular pressure, a detailed anterior and posterior segment examination including gonioscopy, dilated fundus and optic disc examination, visual fields, stereo disc photography, optical coherence tomography imaging, and measurement of central corneal thickness. Main Outcome Measures The baseline characteristics of gender, age, and glaucoma diagnosis were collected. Body mass index (BMI), hypertension, diabetes, and alcohol and tobacco use, as well as ocular conditions including blindness, cataract, non-proliferative diabetic retinopathy, age-related macular degeneration, and use of ocular medication and surgery, were examined. Median population density, income, education level, and other socioeconomic measures were determined for the study cohort. Results Of the 2,520 African-Americans recruited to the POAAGG study to date, 2,067 (82.0%) including 807 controls and 1,260 POAG cases met all inclusion criteria and completed the detailed clinical ocular exam. Cases were more likely to have a lower BMI (p<0.01) and report a history of blindness (visual acuity of 20/200 or worse, p<0.001), while controls were more likely to have diabetes (p<0.001), have non-proliferative diabetic retinopathy (p=0.02), and be female (p<0.001). Study participants were drawn largely from predominantly African-American neighborhoods (African-American population 67.7-70.0%) of low income, high unemployment, and lower education, surrounding the University of Pennsylvania. Conclusions The POAAGG study has currently recruited over 2,000 African-Americans eligible for a POAG genetics study. Blindness and low BMI were significantly associated with POAG. This population was predominantly recruited from neighborhoods whose population income exists at or near the Federal Poverty Level.

Purpose To determine the risk factors associated with progression to blindness from primary open-angle glaucoma (POAG) in an African-American population. Methods This study examined 2119 patients enrolled in the Primary Open-Angle African-American Glaucoma Genetics (POAAGG) study. A total of 59 eyes were identified as legally blind as a result of POAG (cases) and were age-and sex-matched to 59 non-blind eyes with glaucoma (controls). Chart reviews were performed to record known and suspected risk factors. Results Cases were diagnosed with POAG at an earlier age than controls (p = 0.005). Of the 59 eyes of cases, 16 eyes (27.1%) presented with blindness at diagnosis. Cases had worse visual acuity (VA) at diagnosis (p < 0.0001), with VA worse than 20/40 conferring a 27 times higher risk of progression to blindness (p = 0.0005). Blind eyes also demonstrated more visual field defects (p = 0.01), higher pretreatment intraocular pressure (IOP; p < 0.0001), and higher cup-to-disc ratio (p = 0.006) at diagnosis. IOP was less controlled in cases, and those with IOP ≥21 mmHg at more than 20% of follow-up visits were 73 times more likely to become blind (p < 0.0001). Cases missed a greater number of appointments per year (p = 0.003) and had non-adherence issues noted in their charts more often than controls (p = 0.03). However, other compliance data did not significantly differ between groups. Conclusion Access to care, initial VA worse than 20/40, and poor control of IOP were the major risk factors associated with blindness from POAG. Future studies should examine earlier, more effective approaches to glaucoma screening as well as the role of genetics in these significantly younger patients who progress to blindness.

The risk conferred by positive FH suggests strong genetic underpinnings for some patients with this disease, which will be investigated by genome-wide association studies and whole exome sequencing. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.