Electron Microscopic Demonstration of Intraretinal Virus Particles in Cytomegalic Inclusion Disease

A case of retinal cytomegalovirus infection which was previously reported by light microscopy, was restudied by electron microscopy. The paraffin-embedded tissue was used. Cytomegalovirus particles were found within intranuclear inclusion bodies and within the cytoplasm of unidentified retinal cells. The diagnosis of the case and the diagnostic value of the intranuclear inclusion bodies were confirmed. Observability of the inclusion bodies depended upon postfixation handling of the tissue. The case gives another example for the usefulness of electron microscopy in histopathologic diagnosis of tissues primarily prepared for conventional light microscopy.