Low Body Mass Index Poses Greater Risk of Primary Open-Angle Glaucoma in African Ancestry Individuals

center dot PURPOSE: Investigate the relationship between body mass index (BMI) and primary open-angle glaucoma (POAG) in an African ancestry cohort from the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study. center dot DESIGN: Retrospective, cross-sectional "case-control" comparison study. center dot METHODS: A total of 6,634 POAAGG study subjects were eligible: 2,977 cases and 3,657 controls. Ocular and demographic data were collected from on-site exams, standardized interviews, and electronic medical records. BMI was calculated: weight(kg)/height(m)2, and categorized as low ( < 18.5), moderate (18.5-24.9), high (25.0-29.9), or very high ( >= 30). Structural and functional POAG progression were assessed by annual rate of change in retinal nerve fiber layer thickness and visual field mean deviation, respectively, using a linear mixed- effects model. Regression analyses evaluated associations of BMI with POAG status, phenotype, and progression. center dot RESULTS: Lower BMI was associated with increased POAG risk (aOR[95% confidence interval], 1.02 [1.007,1.023] per kg/m(2) decrease in BMI, p = .0003). In cases, low BMI was associated with larger cup-to-disc ratio ( p = .007) and worse visual acuity ( p = .04). Fast functional POAG progressors had a significantly lower mean BMI than slow progressors (25.7 vs. 30.0 kg/m(2), p = .04). center dot CONCLUSIONS: In this African ancestry cohort, low BMI was associated with increased POAG risk. POAG cases with low BMI were more likely to have larger cup- to-disc ratios, worse visual acuity, and faster functional progression, indicating more severe glaucoma. (Am J Ophthalmol 2025;271: 119-126. (c) 2024 Published by Elsevier Inc.)