Ultrastructural Analysis of Experimental Allergic Uveitis in Rabbit

Abstract

Bilateral posterior uveo-retinitis was induced in 6 pigmented rabbits by unilateral subconjunctival injection of 50 μg of retinal soluble antigen (S-antigen) in complete Freund’s adjuvant. Ultrastructurally the inflammation revealed four distinct phases of target cell desctruction in the retina. Initially there was a coagulative necrosis of the outer segments of the photoreceptor cells, followed by phagocytosis of these outer segments by mononuclear cells. Next, there was hydropic degeneration and necrosis of the inner segments and the cell bodies, and finally there was proliferation of the retinal pigment epithelium and enlargement of the Müller cells to replace the necrotic photoreceptors. The localized damage to the photoreceptor cells indicates that these cells are the target site in the inflammation induced by S-antigen.