Frequency of diabetic retinopathy in the adult population in China: the Beijing Eye Study 2001.

To evaluate the prevalence of diabetic retinopathy and its impact on visual impairment in China. The Beijing Eye Study, a population-based study on inhabitants aged 40+ years in rural and urban regions of Greater Beijing included 4,439 subjects out of 5,324 subjects invited to participate. Fundus photographs of the worse eye per subject were graded using the early treatment of diabetic retinopathy study criteria. The minimum criterion for diagnosis of diabetic retinopathy was the presence of at least one microaneurysm. Gradable fundus photographs were available for 4,391 (98.9%) subjects. Diabetic retinopathy was detected in 285 subjects (6.5% of the total study population). Most of the diabetic retinopathy was of the mild type (91.9%). Eleven subjects (3.9%) had the moderate nonproliferative type, and 12 subjects (4.2%) had proliferative retinopathy. Diabetic retinopathy was associated with age [P < 0.001; odds ratio (OR) 1.02; 95% confidence interval (CI) 1.01, 1.04], and self-reported diagnosis of arterial hypertension (P = 0.036; OR 1.39; 95%CI 1.02, 1.88) and of hyperlipidemia (P = 0.029; OR 1.39; 95%CI 1.04, 1.88). One subject (0.02%) out of the total study population was blind due to diabetic retinopathy. Diabetic retinopathy caused 8% of all blindness in the total study population. Diabetic retinopathy was detected in about 7% of adult Chinese aged 40+ years. Visual impairment due to diabetic retinopathy was relatively uncommon in the adult Chinese population as compared with in Western populations. Factors associated with diabetic retinopathy were age, and self-reported diagnosis of arterial hypertension and of hyperlipidemia.