Clinical study of venous abnormalities in diabetic retinopathy.

The authors studied 304 eyes (248 cases) affected by diabetic retinopathy in relation to venous abnormalities. The posterior pole and surrounding mid-peripheral area were examined by ophthalmoscopy, slit-lamp examination with contact lens and fluorescein angiography. There were 225 eyes with preproliferative and 79 eyes with proliferative retinopathy. Fifty-six eyes (18%) of the total eyes had venous abnormalities: 17 (8%) of the 225 eyes with preproliferative retinopathy and 39 (49%) of the 79 eyes with proliferative retinopathy. In the 56 eyes with venous abnormalities, 54 (96%) showed beading, 14 (25%) showed looping and 2 (4%) showed duplication. All eyes which showed looping or duplication had proliferative retinopathy. The locations of the venous abnormalities were analyzed: 42% were in secondary branches, 27% in tertiary branches, 18% in primary branches, 10% in fourth branches and 3% in fifth branches. The portion of the fundus affected was upper temporal, lower temporal, upper nasal and lower nasal in 28%, 22%, 29% and 21%, respectively. Based on our results, eyes with looping or duplication on ophthalmoscopic or slit-lamp examination have an extremely high probability of being in some stage of proliferative retinopathy. Retinopathy should be confirmed by fluorescein angiography and photocoagulation should be performed as quickly as possible.