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 prediabetic condition, may be a risk factor for the development of cortical cataract.