Measles retinopathy. A hamster model of acute and chronic lesions.

Measles and subacute sclerosing panencephalitis strains of virus inoculated intracerebrally in suckling and weanling hamsters spread immediately to the eye via the blood. Virus replicates in the brain and eye in parallel, and in higher titers than it does in other organs. Acute retinal lesions consist of focal syncytia, inclusion-bearing cells, and necrosis. Immunofluorescence studies show measles-specific antigen in the affected cells. Ultrastructurally, measles nucleocapsids and virions are seen in the retinal cells. The necrosis is followed by a differential repair of the retinal layers that results in retinal dysplasia. Chronically, the retinal dysplasia progresses to atrophy and gliosis of the retina. The chronic lesions are histologically similar to those seen in human subacute sclerosing panencephalitis and measles retinopathies.