Abstract
Fully penetrating corneal grafts were made between unrelated albino rabbits. Rejection was induced, and was regularly accompanied by invasion of the host cornea by superficial vessels. Advancing rejection was evidenced by stromal haze and thickening in the rejected portion of the graft. It was possible to study the clinically normal unrejected portion, the interface between it and the affected portion, and the obviously abnormal portion of the graft, as well as the host region and scar. The endothelium of the clear portion of the graft was found to be infiltered by lymphocytes which penetrated between cells, but did not reach Descemet's membrane. The endothelial cell apparently closed over the lymphocytes after the invasion. The leukocytes, therefore, were in the endothelial intercellular space. In the interface between the clear and turbid portions of the grafts, fibrin present in the anterior chamber was found on the endothelial surface accompanied by mononuclear cells--mainly lymphocytes. They pushed between adjacent endothelial cells; in some instances they reached Descemet's membrane. The endothelial cells' cytoplasm was remarkably little affected inthis area. Mitochondria, endoplasmic reticulum, and the terminal web appeared qualitatively normal. The cells, however, became attenuated in some portions and greatly thickened in others. Their surface adjacent to the anterior chamber was frequently covered by minute processes not found normally. In the region which appeared clinically hazy, it was obvious that Descemet's membrane was exposed to the aqueous humor in places. The membrane was otherwise covered by mononuclear leukocytes and remaining endothelial cells. Many of the latter were greatly rounded and apparently in a processof desquamation.