Experimental corneal calcification in animals treated with dihydrotachysterol.

Several methods of producing calcification of the cornea in experimental animals are presented. Experimental corneal calcification resulted from a combination of treatment with dihydrotachysterol (DHT) and corneal injury. In rabbits, six varieties of corneal injuries were inflicted: de-epithelization of the entire or central part of the cornea, abrasion of the central posterior surface, a combination of these procedures, freezing, and intracameral injection of potassium permanganate. Freezing the central cornea was the simplest and most effective process for the rabbit. In the rat, de-epithelization of either the entire or central cornea proved most effective of the methods employed. In both species, calcification occurred within one week and teas always found just beneath the corneal epithelium. Treatment with DHT proved necessary for mineralization, no matter what the operational procedure. The presence of calcium deposits in tissue sections was demonstrated by von Kossa's histochemical method and *Ca autoradiography. Moderate calcification persisted for many months. Larger subepithelial plaques provoked vascularization and rapid disappearance of the calcium deposits. The procedures employed are discussed in terms of their possible usefulness in future studies of corneal and other soft tissue calcification. A possible role of fibroblasts is suggested.