Prevalence and Risk Factors of Blindness Among Primary Angle Closure Glaucoma Patients in the United States: An IRIS® Registry Analysis.

PURPOSE: To assess the prevalence and risk factors of blindness among patients newly diagnosed with primary angle closure glaucoma (PACG) in the United States (US). DESIGN: Retrospective cross-sectional study. METHODS: Eligible patients from the American Academy of Ophthalmology (AAO) IRIS® Registry (Intelligent Research in Sight) had newly diagnosed PACG, defined as: 1) observable during a 24-month lookback period from index date of PACG diagnosis; 2) no prior history of eye drops, laser, or cataract surgery unless preceded by a diagnosis of anatomical narrow angle (ANA); 3) no prior history of glaucoma surgery. Logistic regression models were developed to identify risk factors for any (one or both eyes) or bilateral (both eyes) blindness (visual acuity ≤ 20/200) at first diagnosis of PACG. RESULTS: Among 43,901 eligible patients, overall prevalence of any and bilateral blindness were 11.5% and 1.8%, respectively. Black and Hispanic patients were at higher risk of any (OR=1.42 and 1.21, respectively; p<0.001) and bilateral (OR=2.04 and 1.53, respectively; p<0.001) blindness compared to non-Hispanic White patients adjusted for ocular comorbidities. Age <50 or >80 years, male sex, Medicaid or Medicare insurance product, and Southern or Western practice region also conferred higher risk of blindness (OR>1.28; p≤0.01). CONCLUSIONS AND RELEVANCE: Blindness affects 1 out of 9 patients with newly diagnosed PACG in the IRIS® Registry. Black and Hispanic patients and Medicaid and Medicare recipients are at significantly higher risk. These findings highlight the severe ocular morbidity among PACG patients and the need for improved disease awareness and detection methods.