Management of high-risk corneal transplantation

Abstract

The cornea is the most commonly transplanted tissue in medicine. The main cause of corneal graft failure is allograft rejection. The incidence of graft rejection depends on the presence of high-risk characteristics, most notably corneal neovascularization. Although corneal grafting has high success rates in the absence of these risk factors, high-risk keratoplasty is associated with low success rates because of a high incidence of immune-mediated graft rejection. To improve the survival of high-risk corneal transplantation, various preoperative, intraoperative, and postoperative measures can be considered; however, the key step in the management of these grafts is the long-term use of local and/or systemic immunosuppressive agents. Although a number of immunosuppressive agents have been used for this purpose, the results vary significantly across different studies. This is partly due to the lack of an optimized method for their use, as well as the lack of a precise stratification of the degree of risk in each individual patient. New targeted biologic treatments, as well as tolerance-inducing methods, show promising horizons in the management of high-risk corneal transplantation in near future.

Keywords: cornea; graft rejection; high-risk; immunosuppression; neovascularization; transplantation.

Fig. 1

High-risk corneas with different degrees of corneal neovascularization: mild (A), in a patient with corneal scar after infectious keratitis; moderate (B), in a patient with longstanding bullous keratopathy; and severe (C), in a patient with the failure of the third corneal graft with associated ocular surface inflammation.