Diabeteslike preproliferative retinal changes in galactose-fed dogs
Y. Takahashi, M. Wyman, F. Ferris 3rd and P. F. Kador
National Eye Institute, National Institutes of Health, Bethesda, Md. 20892.
Retinal vessel changes were experimentally investigated by a combination of
color fundus photography, fluorescein angiography, and histologic studies
in beagles that were fed a 30% galactose diet for up to 66 months.
Previously, we have described the appearance of pericyte ghosts,
microaneurysms, acellular capillaries, and intraretinal hemorrhages in dogs
fed a galactose diet for up to 36 months. These disorders were similar to
those observed in humans with background diabetic retinopathy. We report
herein that dogs fed galactose for 48 to 60 months experience retinal
changes associated with the chronic occlusion of capillary beds and
subsequent ischemia of the retina. These changes included the appearance of
broad areas of nonperfusion, soft exudates (cytoid bodies), intraretinal
microvascular abnormalities, occluded arterioles, preretinal and
intravitreal hemorrhages, and apparent new vessel growth around the optic
disc. The present study clearly demonstrates that the galactose-fed dog is
an animal model in which advanced retinal changes develop, and these
changes are similar to those associated with preproliferative human
diabetic retinopathy.
