The ocular fundi of the Royal College of Surgeons (RCS) dystrophic rats were examined by conventional fundus photography, fluorescein angiography (FA) and indocyanine green angiography (IA). In the fundus, a reddish colored background was observed in the RCS dystrophic rats at 3 weeks of age. At 9 weeks of age, the background had changed to pale in color. In FA, the RCS dystrophic rats at 3 week of age demonstrated background fluorescence with homogeneous brightness. Fluorescent dye leakage was

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... observed in the late phase of the postinjection period at 9 weeks of age. In IA, the RCS dystrophic rats at 3 weeks of age had background fluorescence with homogeneous brightness, and at 5 weeks of age, spots of hyperfluorescence were scattered over the dark background. At 7 weeks of age, numerous delimited, irregular round spots of hyperfluorescence appeared over the dark background. Such hyperfluorescent lesions had further increased in number and size in the RCS dystrophic rats at 9 weeks of age. In this way, ocular findings related to abnormalities in the retinal pigment epithelium and choroid in the RCS dystrophic rat were demonstrated by fundus photography, fluorescein angiography and indocyanine green angiography. Key words: fluorescein angiography, indocyanine green angiography, retinal degeneration, retinal pigment epithelium, Royal College of Surgeons dystrophic rat 99% reduction in the number of photoreceptors in the outer nuclear layer by 2 to 3 months after birth. In addition to degeneration of photoreceptor cells, changes in the retinal vasculature have been described in this animal model for retinal degeneration by means of intravenous histochemical demonstration with horseradish peroxidase [3, 4] , but there is little information on the fundus or angiographic analysis with the RCS dystro-