RETINAL AND CHOROIDAL NEOVASCULARIZATION IN A TRANSGENIC MOUSE MODEL OF SICKLE-CELL DISEASE

A complication of sickle cell disease is proliferative retinopathy. We investigated the eyes from a transgenic mouse model of sickle cell di sease (alpha(H) beta(S)[beta(MDD)] type) to determine if pathological changes occurred in their retinas and choroids. One retina from each a nimal was processed by flat-embedding adenosine diphosphatase-reacted retinas in glycol methacrylate. The fellow eye from each animal was em bedded whole in glycol methacrylate for histopathological analysis of all ocular structures Retinal vascular occlusions resulted in nonperfu sed areas of retina and arterio-venous anastomoses. Intra- and extrare tinal neovascularization was observed adjacent to nonperfused areas. R etinal pigmented lesions were formed by the migration of retinal pigme nt epithelial cells into sensory retina, often ensheathing choroidal n eovascularization. Tbe incidence of this bilateral chorioretinopathy w as 30% in animals older than 15 months of age. The ocular histopatholo gical changes we observed in the mouse model mimicked many aspects of human proliferative sickle cell retinopathy. Furthermore, this is the first genetically derived animal model for chorio-retinal neovasculari zation.