Angiographic abnormalities of experimental autoimmune uveoretinitis

Experimental autoimmune uveoretinitis (EAU) is an invaluable animal model for studying inflammatory eye disease in humans. Indocyanine green (ICG) is a fluorescent dye that can be used to image both retinal and choroidal vessels. This study was performed to examined the retinal and choroidal vascular abnormalities of a rat model of EAU using ICG and fluorescein as the contrast media to assess the suitability of this model for studying ICG angiographic abnormalities in inflammatory eye disease in humans.

Twenty-six black-hooded Lister rats were inoculated with bovine retinal S-antigen plus adjuvant with or without Bordetella pertussis antigen. Fluorescein and ICG angiograms were performed at different stages of clinical disease with a scanning laser ophthalmoscope.

EAU was more severe and primarily choroidal disease in rats given Bordetella pertussis, but no animals showed evidence of dye leakage from large choroidal vessels. There was frank leakage of indocyanine green from retinal vessels. Leakage of both fluorescein and ICG retinal vessels largely correlated with disease activity. Retinal pigment epithelial lesions either corresponded to areas of hypofluorescence on the ICG angiogram alone or were represented by areas of ICG hyperfluorescence that had overlying areas of fluorescein leakage from retinal capillaries.

This study has demonstrated the vascular abnormalities of this model of EAU using ICG and fluorescein as the contrast media. The suitability of this method for studying ICG angiographic abnormalities in inflammatory eye disease in humans is encouraging.