Arrest of myelination and demyelination in rabbit retina induced by herpes simplex virus infection.

Herpes simplex virus was injected into the vitreous of suckling and adult rabbits. In the suckling rabbits the infection caused an arrested myelination of the strip. Further, the infected strips showed degenerative changes with splitting and distension of myelin sheaths which then disintegrated. Ultrastructurally, herpes simplex virus particles were found in both oligodendroglial cells and in astrocytes in the bundles. No increase in intraocular pressure was recorded during the inflammation. The infection spread along optic pathways to the opposite side. Inflammatory cells appeared at the surface and infiltrated the degenerating strip. Especially in the contralateral eye, an extensive inflammatory cell infiltration was seen among bundles of nerve fibres which showed partly well-preserved myelin and partly with signs of demyelination reminiscent of the picture of experimental allergic encephalomyelitis in the epiretinal strip.