Visual Impairment as a Marker of Systemic Vulnerability and Cause-Specific Mortality in U.S. Adults.

Abstract

To determine whether the excess mortality associated with visual impairment (VI) in U.S. adults is driven primarily by non-cardiovascular, non-cancer causes of death rather than cardiovascular or malignant causes. Population-based cohort study. Adults aged 40 years or older participating in the National Health and Nutrition Examination Survey (NHANES) 2001-2008 with measured presenting visual acuity in both eyes and eligibility for linkage to the National Death Index. Presenting visual impairment was defined as visual acuity worse than 20/40 in the better-seeing eye using standardized examination protocols. Mortality outcomes were ascertained through December 31, 2019. Survey-weighted Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for demographic, socioeconomic, and clinical covariates. All-cause mortality. Secondary outcomes included non-cardiovascular, non-cancer mortality, cardiovascular mortality, and cancer mortality. The analytic cohort included 11,938 participants, of whom 1179 (9.9%) had visual impairment at baseline. Over a mean follow-up of 13.2 years, visual impairment was most strongly associated with non-cardiovascular, non-cancer mortality (adjusted HR, 1.55; 95% CI, 1.30-1.84). Visual impairment was also associated with increased all-cause mortality (HR, 1.36; 95% CI, 1.17-1.57) and cardiovascular mortality (HR, 1.33; 95% CI, 1.02-1.72), but not cancer mortality (HR, 0.98; 95% CI, 0.69-1.40). Associations were robust across sensitivity analyses, including exclusion of participants with diabetes, exclusion of early deaths, and alternative visual impairment thresholds. In this nationally representative cohort, visual impairment was independently associated with increased mortality, driven primarily by non-cardiovascular, non-cancer causes of death. These findings suggest that vision loss may serve as a marker of systemic vulnerability and support integrating vision assessment into chronic disease management and preventive care strategies.