Abstract
Purpose: :
Cataracts and other chronic diseases of the elderly, such as cognitive impairment, may share common underlying pathological mechanisms in oxidative damage. Our study examines the association between cataract and cognitive function in the AREDS population.
Methods: :
2546 AREDS participants age 60–80 years, with lens photographs at baseline and annual visits, were included in the study. Lens status was assessed at a reading center by trained and certified graders, using the Age–Related Eye Disease System for Classifying Cataracts. Trained examiners assessed cognitive function at a median follow–up time of 6.9 years. A General Linear Model (GLM) was used to compare the mean scores on the Modified Mini Mental State Examination (3MSE) of those with cataract and without cataract at baseline. The association of cataract status at baseline with 3MSE outcome at follow–up was assessed by logistic regression. In addition, the correlation between cataract progression, defined as the difference in cataract grades between baseline and follow–up, and cognitive function was assessed with a GLM, adjusting for baseline cataract status. All models were adjusted for age, sex, race, education, refractive error, diabetes, depression, age–related macular degeneration, and history of cataract surgery, using the log likelihood selection criteria.
Results: :
Persons with no cataract at baseline performed significantly better than those with cataract at baseline on the 3MSE, at a mean follow–up time of 6.9 years (93.2±6.2 vs. 91.2±6.15, p=.002). The presence of cataract at baseline was associated with a 42% increased chance of being in the lowest decile on 3MSE at follow–up (OR = 1.42; 95% CL = 1.03–1.96). When adjusted for baseline cataract status, the progression of nuclear and cortical cataract was not associated with 3MSE outcome (p=.9 and p=.3 for nuclear and cortical, respectively).
Conclusions: :
The presence of baseline cataract was associated with poorer cognitive function at follow–up in the AREDS population.
Keywords: cataract • memory • clinical (human) or epidemiologic studies: risk factor assessment