Retinitis in euthymic mice following inoculation of murine cytomegalovirus (MCMV) via the supraciliary route.

Cytomegalovirus (CMV) retinitis is the most frequent infectious ocular complication of the acquired immune deficiency syndrome (AIDS). Currently, there are few animal models to study the virologic and immunologic factors which contribute to the pathogenesis of CMV retinitis. In these experiments, 1-2 X 10(4) PFU of murine cytomegalovirus (MCMV) was inoculated into the supraciliary space of BALB/c mice. Within three days of inoculation, moderate iridocyclitis was observed which progressed to necrosis of the ciliary body by day 14. Approximately 60% of the mice developed typical retinitis characterized by virus-infected cytomegalic cells in the retina and retinal pigment epithelium, focal retinal infiltrates, transition zones between uninvolved and involved retina, and optic neuritis. The remaining animals exhibited atypical retinitis characterized by non-specific retinal inflammation in the absence of obvious viral infection. This murine model of CMV retinitis shares some features with retinitis observed in AIDS patients with CMV retinitis and may be useful to evaluate the efficacy of immunologic and/or pharmacologic treatment strategies for CMV retinitis.