Diabeteslike proliferative retinal changes in galactose-fed dogs
P. F. Kador, Y. Takahashi, M. Wyman and F. Ferris 3rd
National Eye Institute, National Institutes of Health, Bethesda, Md.
OBJECTIVE: To determine whether diabeteslike lesions associated with the
proliferative stage of diabetic retinopathy develop in galactose-fed dogs,
since studies designed to define the complex biochemical effects of
prolonged hyperglycemia on retinal vessels have been hampered by the lack
of an animal model that mirrors both the early and advanced stages of
diabetic retinopathy. METHODS: Eyes from 9-month-old male beagles fed a
daily diet containing either 30% nonnutrient filler (control diet) or 30%
galactose (galactose diet) for up to 84 months were enucleated and
histologically examined. RESULTS: Retinal vessel changes associated with
the proliferative stage were observed in two of nine galactose-fed dogs
while the remainder demonstrated retinal changes that included the
appearance of microaneurysms, acellular capillary beds associated with
areas of nonperfusion, and intraretinal microvascular abnormalities.
Proliferative changes were evidenced by the formation of preretinal fibrous
membranes and the appearance of fibrovascular membranes on the retinal
surface and on the posterior hyaloid membrane. No retinal lesions were
observed in similar dogs fed a control diet for up to 84 months.
CONCLUSION: The galactose-fed dog appears to be the first animal model that
can develop diabeteslike retinal vessel changes associated with both the
early and advanced stages of retinopathy, including the proliferative
stage.
