[Epidemiologic study of diabetic retinopathy in nine hospitals in the Aomori area]

To examine the prevalence of diabetic retinopathy and the relationship between diabetic retinopathy and systemic risk factors.

A cross sectional study of diabetic retinopathy was conducted on 1,826 eyes of 913 randomly selected patients with type 2 diabetes in 9 central hospitals in Aomori Prefecture and the surrounding district. Retinopathy levels and maculopathy were assessed by binocular funduscopy, fundus photography and, if necessary, by fluorescein angiography. Multiple logistic regression analysis was performed to determine independent effects of systemic risk factors on diabetic retinopathy.

The prevalence of background retinopathy was 31%, of preproliferative retinopathy 5%, and of proliferative retinopathy 5% in all patients. However, in 3 hospitals in which the patients were routinely examined by fluorescein angiography, background retinopathy was found to be present in 60%, preproliferative retinopathy in 5%, and prolifertive retinopathy in 7%. Maculopathy was found in 8% of diabetic patients and the prevalence was 11% in the eyes with background retinopathy, 40% with preproliferative retinopathy, and 50% with proliferative retinopathy. Multiple logistic regression analysis showed that retinopathy was significantly associated with duration of diabetes, methods of diabetic control, hypertension, nephropathy, and neuropathy.

The detection rate of background diabetic retinopathy by fluorescein angiography was twice as sensitive as that by binocular funduscopy and fundus photography. The prevalence of maculopathy increases with the progression of retinopathy. Several systemic risk factors have significant association with diabetic retinopathy and maculopathy.