Fine structure of the reindeer cornea in normal conditions and in keratitis.

The fine structure of the reindeer cornea in normal conditions and in spontaneous keratitis was described. There were more layers of squamous and fewer layers of polyhedral cells than in pigs, cattle and horses. Mild cases of corneal opacity just had some swollen superficial epithelial cells. When fully developed the keratitis had all the characteristics of an acute inflammation. Swelling or shrinking of the epithelial cells with or without degenerative nuclear changes were common. A striking alteration of the epithelial cells was the irregular appearance of the filaments which was frequently observed. In some cases there was pronounced intercellular oedema with desquamation of the superficial squamous cells and occasional neutrophils in the intercellular space. The stroma was the site of oedema, infiltration of leukocytes and vascularization. The aetiology and pathogenesis of the disease are not yet established but experimental research on these problems is in progress.