Diabetic retinopathy is the leading cause of blindness. In Japan about
45% of diabetic patients under medical care have retinopathy and 10%
have proliferative retinopathy. Until recently, Scott's classification
(1953, 1957) of retinopathy was commonly used in Japan, As there are
several problems with this classification, I proposed a new classifica
tion in 1983. It aims to separate benign and malignant types and to be
more useful clinically so that each stage corresponds better to the i
ndication of specific treatment. Diabetic retinopathy is divided into
benign (type A) and malignant (type B) retinopathy, and each type is s
ubdivided into 5 stages. Benign retinopathy is unlikely to cause blind
ness unless maculopathy is present. It includes background retinopathy
(Al and A2) and interrupted proliferative retinopathy (A3, A4 and A5)
after photocoagulation or vitrectomy. Malignant retinopathy is likely
to get worse and may lead to blindness if left without specific treat
ment. It includes preproliferative retinopathy (BI), early (B2), advan
ced (B3) and end-stage (B4 and B5) proliferative retinopathy. The pres
ence of specific findings is described by the addition of letters: mac
ulopathy (M), tractional retinal detachment (D), neovascular glaucoma
(G), and ischemic optic neuropathy (N). Systemic metabolic control of
diabetes is the best means of treatment for benign retinopathy, but ma
lignant retinopathy should immediately be seen by ophthalmologists for
specific treatment: focal photocoagulation for B1, focal or panretina
l photocoagulation for B2 and panretinal photocoagulation for B3-B5. V
itrectomy is indicated in B4 or more severe stages.