Purpose: To describe the relationships of diabetes mellitus, cardiovascular disease, and selected cardiovascular disease risk factors to cumulative incidence of age-related cataract and to progression of lens opacities over a 5-year interval.
Methods: A follow-up examination of the Beaver Dam Eye Study cohort was performed 5 years after the baseline evaluation. Ages at the census prior to baseline ranged from 43 to 84 years of age. Protocols for examination, lens photography, and grading were the same for both examinations.
Results: Age at baseline was the most significant characteristic associated with incidence of nuclear, cortical, and posterior subcapsular cataract in those without diabetes (P < .001) for all cataracts. The positive association of age with cataract was found for nuclear and cortical cataract in the worse eye (P < or = .04) but not posterior subcapsular cataract in those with diabetes. Progression of nuclear sclerosis was common, occurring in about 70% of subjects when considering either eye. Incident cortical and posterior subcapsular cataracts (P < or = .001 for worse eye for each lesion) and progression of cortical and posterior subcapsular opacities were more common in those with diabetes (P < or = .001 for either eye for each lesion). Increased glycated hemoglobin level was associated with increased risk of nuclear and cortical cataracts in those with diabetes. Relationships of risk factors to posterior subcapsular cataracts, especially among those with diabetes, were often in the expected direction but lacked significance possibly due to small samples.
Conclusions: Diabetes mellitus is associated with incidence over 5 years of cortical and posterior subcapsular cataract and with progression of more minor cortical and posterior subcapsular lens opacities. These changes may be related to level of glycemia. Cardiovascular disease and its risk factors have little effect on incidence of any age-related cataract.