Development of diabetic retinopathy and its associated risk factors in type 2 diabetic patients in Osaka district, Japan: a long-term prospective study

Abstract Incidence rates of diabetic retinopathy and its associated risk factors were studied in a long-term prospective study involving 976 type 2 (non-insulin dependent) diabetic patients that showed no retinopathy at entry to the study. 322 of the patients (one-third of the subjects studied) developed diabetic retinopathy during the observation period (average length 8.3 years). The incidence rate per 1000 person-years was 39.8. The rate was significantly related to age at onset of diabetes, to fasting plasma glucose (FPG) level at entry, and to type of treatment. The incidence rate was also related to the duration of the disease. Glycemic control clearly played a role in the occurrence of retinopathy. Patients with FPG ≥ 200 mg/dl had the highest incidence rate, while patients with FPG