Corneal Opacity in a Japanese White Rabbit

Abstract

Corneal opacity was found in a female Japanese white rabbit. On slit lamp biomicroscopic examination (KOWA SL-5), the opacity was present in both eyes where well demarcated rectangular opacity occupied most of the central part of the cornea with its long axis parallel to the palpebral fissure. The lesions appeared to be composed primarily of myriads of evenly dispersed coarse granules. A vertical linear dense band ran across the rectangles. There were no other notable changes in either of the eyes.

Histological examination of these corneas revealed disarrangement of the subepithelial lamella structure. The collagen fibers in the regions of the opacity were swollen, arranged haphazardly and formed a disoriented corneal stromal mass. Toward the periphery of the corneas, a few persistent capillaries were apparent. There also was cellular infiltration consisting primarily of plasma cells at each limbus. Special staining including PAS and Von Kossa was negative for the stromal lesions.

On the basis of these findings, the corneal opacity most likely represented a chronic stage of keratitis. The etiology is uncertain, but probably traumatic.