The BB Wistar rat: an experimental model for the study of diabetic retinopathy

Diabetic retinopathy was studied in the spontaneously diabetic BB Wistar rat with respect to qualitative and quantitative structural changes. Trypsin-digested retinal preparations revealed after 8 to 11 months of diabetes a decrease in the pericyte/endothelial cell ratio. Quantitative ultrastructural examinations showed no increase in the vascularity or in basement-membrane thickness in diabetic animals. However, retinal capillaries showed not infrequently occlusions by fibrin and platelet thrombi.