Morphology of experimental vaccinial superficial punctate keratitis--a scanning and transmission electron microscopic study.

Rabbit corneas infected with vaccinia virus were studied by scanning electron microscopy. The earliest detectable lesion consisted of tiny punctate epithelial pits lined by the intact superficial layers of the epithelium. These lesions were presumed produced by the dissolution of the wing cells with inward collapse of the overlying superficial layer. Examination of more advanced and severe lesions suggested that the further progression consisted of erosion through the superficial layer followed by erosion internally through the basal layer to expose the stroma. With coalescence of adjacent lesions, the punctate appearance of these lesions was lost.