Factors related to the development and progression of diabetic retinopathy in patients with type 2 diabetes.

This study was intended to clarify the factors associated with the development and progression of diabetic retinopathy in patients with Type 2 diabetes. A total of 107 patients with Type 2 diabetes underwent fundoscopic examination by an ophthalmologist, and the factors that might be associated with the severity of retinopathy were investigated. Analysis of variance and the chi 2 test were performed to determine whether 22 separate factors were associated with the severity of diabetic retinopathy. There were significant associations between retinopathy and duration of disease, systolic blood pressure, urinary albumin index, and blood urea nitrogen. Multiple regression analysis with retinopathy as the criterion variable and 20 other factors as explanatory variables revealed that, of those explanatory variables showing statistical significance, the strongest associations were with duration of disease and type of diabetic therapy, in that order. The chi 2 test also revealed significant associations between retinopathy and both the type of diabetic therapy and the use of anti-hypertensive therapy. The results suggest that the duration of illness and the type of diabetic therapy are strongly related to the development and progression of retinopathy in patients with Type 2 diabetes. These findings suggest that insulin deficiency in patients with Type 2 diabetes should be corrected as early and as vigorously as possible, and that modification of daily activities to achieve a more nearly non-diabetic state should be instituted first, with supplementary drug therapy added as required.