Mixed lens opacities and subsequent mortality

Background: Previous studies have found an association between cataract or lens opacity and increased risk of mortality. Further work on determining explanatory factors for this association is needed. Objectives: To determine, in a population-based cohort of older persons, the 2-year risk of death associated with different types of lens opacities; whether an association of mortality and lens opacity is explained by confounding risk factors such as smoking, diabetes, age, race, and sex, which are known to be related to opacity and mortality; whether lens opacity is a marker for health status; and whether there are differences in cause-specific mortality for persons with and without lens opacity. Main Outcome Measure: Two-year mortality rate. Methods: The Salisbury Eye Evaluation Project consists of a random sample of 2520 residents of Salisbury, Md, aged 65 to 84 years. At baseline, lens photographs were taken to document nuclear, cortical, posterior subcapsular cataract, and mixed opacities. Data on education, smoking, alcohol use, hypertension, diabetes and other comorbid conditions, handgrip strength, and body mass index were also collected. Two-year follow-up was conducted for mortality and cause of death. Results: Nuclear opacity, particularly severe nuclear opacity, and mixed opacities with nuclear were significant predictors of mortality independent of body mass index; comorbid conditions, smoking, age, race, and sex (mixed nuclear: odds ratio, 2.23; 95% confidence interval, 1.26-3.95). Conclusion: Lens opacity status is an independent predictor of 2- year mortality, an association that could not be explained by potential confounders.