Clinical Aspects of the Corneal Homograft Reaction

¹ Wilmer Ophthalmological Institute, The Johns Hopkins Hospital and University, Baltimore, Md.

The following evidence has been used to suggest that delayed clouding of penetrating corneal homografts is due to an allergic reaction to the homografted tissue: It has been shoivn experimentally that almost all other tissues will elicit and respond to a homograft reaction. It has been shoivn experimentally that the corneal stroma and endothelium will elicit and. respond to the homograft reaction in rabbits. Clinically, in man and animals, the reaction is limited, primarily to the grafted tissue. This reaction occurs most frequently in vascularized corneas. Autografts of corneas do not produce a similar response. Delayed clouding of a corneal homograft responds to steroid therapy under certain conditions. The evidence that lamellar corneal homografts become opaque because of an allergic reaction to homografted tissue is not so well documented as similar evidence with respect to penetrating grafts. However, the fact that corneal stroma can elicit and respond to the homograft reaction when placed in a vascular bed in the subcutaneous tissue suggests the concept that it may do so when placed in a vascular bed in the cornea. This reaction in the corneal bed may be manifested by clouding of the graft or deposition of lipid at the donor-recipient interface.