Ocular effects of scrapie agent in hamsters: preliminary observations.

Scrapie is caused by one of a group of so-called slow viruses responsible for the subacute spongiform encephalopathies. In the present study, young hamsters were inoculated intracerebrally with hamster-adapted scrapie agent. At termination, all inoculated animals showed signs and central nervous system pathology compatible with scrapie infection. The eyes appeared well developed grossly, but histologically the retina and optic nerve were abnormal. There were varying degrees of thinning of the retina, with the photoreceptor layer being most severely affected. Although the ganglion cell layer was not much different from the controls, the optic nerve appeared more cellular than that of the controls.