Risk Factors Associated With Incident Cataracts and Cataract Surgery in the Age-Related Eye Disease Study (AREDS): AREDS Report Number 32
Year of Publication
Chang, JR; Koo, E; Agron, E; Hallak, J; Clemons, T; Azar, D; Sperduto, RD; Ferris, FL 3rd; Chew, EY; Age-Related Eye Disease Study Group
Antioxidants/administration & dosage*; Cataract Extraction/statistics & numerical data; Cataract/classification; Cataract/epidemiology*; Cataract/physiopathology; Cohort Studies; Disease Progression; Female; Macular Degeneration/physiopathology
OBJECTIVE: To investigate potential risk factors associated with incident nuclear, cortical, and posterior subcapsular (PSC) cataracts and cataract surgery in participants in the Age-Related Eye Disease Study (AREDS). DESIGN: Clinic-based prospective cohort study. PARTICIPANTS: Persons (n = 4425) 55 to 80 years of age enrolled in a controlled clinical trial of antioxidant vitamins and minerals, AREDS, for age-related macular degeneration and cataract. METHODS: Lens photographs were graded centrally for nuclear, cortical, and PSC opacities using the AREDS system for classifying cataracts. Type-specific incident cataracts were defined as an increase in cataract grade from none or mild at baseline to a grade of moderate at follow-up, also with a grade of at least moderate at the final visit, or cataract surgery. Cox regression analyses were used to assess baseline risk factors associated with type-specific opacities and cataract surgery. MAIN OUTCOME MEASURES: Moderate cataract was defined as a grade of 4.0 or more for nuclear opacity, 10% or more involvement within the full visible lens for cortical opacity, and 5% or more involvement of the central 5-mm circle of the lens for PSC opacity. These were graded on baseline and annual lens photographs. RESULTS: A clinic-based cohort of 4425 persons 55 to 80 years of age at baseline was followed up for an average of 9.8±2.4 years. The following associations were found: increasing age with increased risk of all types of cataract and cataract surgery; males with increased risk of PSC and decreased risk of cortical cataracts; nonwhite persons with increased risk of cortical cataract; hyperopia with decreased risk of PSC, nuclear cataract, and cataract surgery; Centrum (Wyeth Consumer Healthcare, Madison, NJ) use with decreased risk of nuclear cataract; diabetes with increased risk of cortical, PSC cataract, and cataract surgery; higher educational level with decreased risk of cortical cataract; and smoking with increased risk of cortical cataract and cataract surgery. Estrogen replacement therapy in female participants increased the risk of cataract surgery. CONCLUSIONS: These findings largely are consistent with the results of previous studies, providing further evidence for possible modifiable risk factors for age-related cataract.