Baseline cataract type and 10-year mortality in the Italian-American Case-Control Study of age-related cataract

Age-related cataract is reported to be associated with increased risk of death. The authors investigated the association of presence and type of cataract with mortality in the participants of the Italian-American Case-Control Cataract Study (Parma, Italy, 1987-1989), which included 1,008 persons aged 45-79 years who had age-related cataract and 469 who had clear lenses. Slit-lamp and retroillumination lens photographs were taken at baseline and graded with the Lens Opacities Classification System II. During 10 years of follow-up (range, 8.9-11.8 years; 11,318 person-years), the authors collected information on 1,429 participants and documented 339 deaths. After adjustment for age, sex, and other mortality risk factors, mixed cataracts with a nuclear/posterior subcapsular component were significantly associated with higher risk of death by Cox proportional hazards regression analyses. Hazard ratios were 2.26 (95% confidence interval (CI): 1.07, 4.76) for nuclear/posterior subcapsular and 1.62 (95% CI: 1.01, 2.61) for cortical/nuclear/posterior subcapsular opacities. In multivariate analysis, mixed types of opacity (any) were associated with increased mortality for malignancy (hazard ratio = 1.81, 95% CI: 1.04, 3.15) and "other" causes (hazard ratio = 2.29, 95% CI: 1.07, 4.92). These findings are compatible with the hypothesis that mixed types of cataract with a nuclear/posterior subcapsular component are indicators of accelerated aging.