Corneal transplantation and immunosuppressants

Abstract

Corneal graft is the most common and most transplanted tissue due to its immune privilege. After corneal transplantation, topical or systemic immunosuppression is applied depending on the patient’s case and condition. Immunosuppressants are a group of drugs that suppress the body's immune system and prevent organ rejection by preventing the transplanted organs from being perceived as foreign by the body and stimulating the body's natural immunity. Immunosuppressants are subdivided into corticosteroids, calcineurin inhibitors, interleukin 2 receptor blockers, and mTOR inhibitors. Inflammation or corneal vascularization in the transplant recipient increases the risk of graft rejection and affects the success of transplantation. To prevent rejection, systemic immunosuppressants are used in high-risk transplantation patients, however, long-term immunosuppressants have low efficacy and severe side effects, making it difficult to manage this process. Patient-specific immunomodulation therapy is currently thought to be the most effective treatment for the high-risk transplantation group. In this review, the characteristics, effects, and efficacy of topical and systemic immunosuppressants used in the post-transplantation period are described in scope of the possibility of corneal graft rejection after transplantation and according to the immune privilege of cornea and risk factors for corneal transplantation. Novel immunoregulators and cellular therapies that may increase the success of corneal transplantation without side effects of immunosuppressants are also emphasized.