Five-year incidence of cataract in older persons with diabetes and pre-diabetes

PURPOSE: To investigate longitudinal associations between diabetes and the 5-year incidence of cataract and cataract surgery. (A population-based, cohort study of 2335 persons with baseline ages 49 years or older resident in the Blue Mountains region, west of Sydney, Australia). METHODS: Baseline information on diabetes history was collected during an interviewer-administered questionnaire. Impaired Fasting Glucose (IFG) was defined as venous plasma glucose between 6.0 and 7.0 mmol/L and newly diagnosed diabetes as plasma glucose >7.0 mmol/L, using fasting blood glucose measurements taken at baseline. Retroillumination lens photographs from the baseline and 5-year follow-up examinations were graded for presence of cortical, posterior subcapsular (PSC) and nuclear cataract. RESULTS: We found a 2-fold higher 5-year incidence of cortical cataract in participants with IFG, multivariate adjusted odds ratio (OR) 2.2, 95% confidence interval (CI) 1.1-4.1. Incident PSC cataract was more frequent among persons with diabetes, but this association was statistically significant only for those with newly diagnosed diabetes, multivariate adjusted OR 4.5 (CI 1.5-13.0). There were no statistically significant associations found between incident nuclear cataract or cataract surgery and either diabetes or IFG. CONCLUSIONS: These epidemiological data suggest that IFG, a pre-diabetic condition, may be a risk factor for the development of cortical cataract.