corneal graft rejection: mechanism, clinical manifestations, diagnosis, and treatment

corneal transplantation is the most common and successful form of solid organ transplantation with a 2-year survival rate of over 90% in low risk cases. this high success rate may be due to the immune privileged status of the cornea, acaid (anterior chamber associated immune deviation) induction phenomena and secretion of inhibitory molecules by corneal cells such as il1-ra, il-1a and fas ligand. however, immunological rejection is the leading cause of corneal graft failure. this process is primarily mediated by cd4+ t cells of the th1 phenotype. the mainstay of corneal graft rejection treatment is topical and systemic steroid. recently topical and systemic cyclosporine a have also yielded promising results. this article reviews the molecular mechanisms of immunity in corneal graft rejection in addition to its prevention and treatment. correct preoperative case selection is vital in preventing graft rejection.