[Epidemiologic study of diabetic preproliferative retinopathy and early stages of proliferative retinopathy].
D000328:Adult; D000367:Age Factors; D000368:Aged; D003930:Diabetic Retinopathy / Q000097:blood / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012737:Sex Factors