Associations of Frailty Index and Composite Dietary Antioxidant Index With Major Ocular Diseases and Analysis of Component Contributions: A Cross-Sectional Study

Purpose: To evaluate the independent and joint effects of the frailty index (FI) and composite dietary antioxidant index (CDAI) with major ocular diseases and quantify contributions of their components. Methods: We analyzed 4455 U.S. adults aged ≥40 years from NHANES 2005-2008. Frailty was defined using a 49-item deficit accumulation FI (FI > 0.21 considered frail), and CDAI was derived from six antioxidants (carotenoids, vitamins A, C, E, selenium, zinc). Weighted multivariable logistic regression, variable importance, restricted cubic spline analyses, and sensitivity analyses assessed associations with retinopathy, cataract, diabetic retinopathy (DR), glaucoma, and age-related macular degeneration. Results: Higher FI was associated with higher odds of all major ocular diseases (any ocular disease: odds ratio [OR] = 1.35; DR: OR = 2.21; glaucoma: OR = 1.34), whereas higher CDAI was associated with lower odds (any ocular disease: OR = 0.97; glaucoma: OR = 0.91). Participants with high FI and low CDAI had the highest odds, based on predefined cutoff categories (any ocular disease: OR = 2.22; DR: OR = 4.92; cataract: OR = 2.50; glaucoma: OR = 3.18; all P < 0.05). Exploratory analyses showed that CDAI contributions varied by disease, whereas chronic disease burden dominated among FI domains. Conclusions: Higher FI and lower CDAI were independently and in combination associated with major ocular diseases, highlighting the relevance of considering frailty status and dietary antioxidant profiles together in ocular health. Translational Relevance: Higher FI and lower CDAI show combined associations with major ocular diseases, emphasizing their relevance to vision-related health.