Immunosuppression in corneal transplantation

Area of Science:

• Ophthalmology
• Transplantation Immunology

Background:

• Post-operative management of keratoplasty and corneal graft rejection relies heavily on corticosteroids.
• Current treatment regimens show significant variability in corticosteroid administration routes and frequencies.
• A lack of a universally accepted definition for 'high-risk' grafts hinders treatment comparison and evaluation.

Purpose of the Study:

• To review clinical post-operative management protocols for keratoplasty.
• To evaluate current strategies for managing corneal graft rejection.
• To propose a standardized risk stratification for corneal grafts to improve treatment consistency.

Main Methods:

• Review of clinical literature on post-operative keratoplasty and graft rejection management.
• Analysis of univariate and multivariate survival studies to identify risk factors.
• Proposal of a risk classification based on recipient corneal vascularization.

Main Results:

• Corticosteroids are the primary treatment for both post-keratoplasty care and graft rejection.
• Recipient corneas can be categorized into low, medium, and high risk based on vascularization (avascular, 1-2 quadrants, 3+ quadrants).
• High-risk cases may require additional immunosuppression, such as systemic cyclosporine, and severe endothelial rejection often necessitates systemic corticosteroids, preferably intravenous methylprednisolone pulses.

Conclusions:

• A standardized risk classification system for corneal grafts, based on vascularization, is proposed to enhance consistency in treatment regimens.
• While corticosteroids are foundational, advanced immunosuppression (systemic cyclosporine or intravenous methylprednisolone pulses) is crucial for high-risk cases and severe rejection episodes.
• Intravenous methylprednisolone pulse therapy is favored over oral steroids for severe rejection due to efficacy and potentially reduced long-term medication burden.