Cataract extraction and cognitive function in older women

BACKGROUND: Oxidative damage is critical in the etiology of cataract. Therefore, associations between cataract and other health endpoints may suggest the shared etiologic role of oxidative stress. METHODS: To assess any role of oxidative stress in cognitive function and early cognitive decline, we investigated the relation between cognition and cataract extraction in 16,197 community-dwelling women age 70-79 years from the Nurses' Health Study. Six cognitive tests were administered by telephone from 1995 to 2000; second interviews are ongoing and have been completed for 12,995 women. In total, 3,597 women reported cataract extraction prior to their baseline cognitive assessment. We used logistic regression to calculate multivariate-adjusted relative risks of a low score and of substantial decline, comparing those with and without cataract extraction. RESULTS: Using a global score that combines the results of the cognitive tests, there was no relation between cataract and either low score (RR = 0.99; 95% CI = 0.87-1.13) or substantial decline from baseline to second interview (RR = 1.08; CI = 0.93-1.25). CONCLUSION: Cataract extraction does not appear to be related to cognitive function in these women.