Ten-Year Survival of Optical Penetrating Keratoplasty and Risk Factors for Graft Failure in Thai Patients

Abstract

© JOURNAL OF THE MEDICAL ASSOCIATION OF THAILAND 2020. Objective: To determine long-term graft survival and identify risk factors for secondary graft failure of optical penetrating keratoplasty (PK) in Thai patients. Materials and Methods: A Retrospective study of patients that underwent optical PK at Siriraj Hospital between January 2002 and December 2005 was done. Results: Of 131 eyes, primary graft failure was found in two eyes (1.5%) thus, 129 eyes were recruited. The three most common surgical indications were pseudophakic or aphakic bullous keratopathy (33.3%), corneal scars (post-trauma, post-infection) (20.9%), and regrafts (16.3%). Mean follow-up period was 93.2 months (1 to 183 months). One-year, 2-year, 5-year, and 10-year graft survival rates were 84.5%, 73.2%, 50.2%, and 24.7%, respectively. The leading cause of graft failure was irreversible allograft rejection (62.5%). Most (56.0%) of the first graft rejection happened within one year post-operatively. Graft survival was lower in eyes with regrafts, history of glaucoma, deep corneal vascularization, peripheral anterior synechiae, and occurrence of one or more rejection episodes. Multivariate regression analysis demonstrated that peripheral anterior synechiae and occurrence of one or more rejection episodes were the significant independent risk factors for graft failure. Considering patients with the clear grafts at the last follow-up, the final best-corrected visual acuity was 6/36 or better in 66.7% eyes and 6/18 or better in 31.6% eyes. Comparing to pre-operative vision, patients with the clear grafts at the last follow-up had improved visual outcome in most eyes (82.5%). Conclusion: Ten-year survival and visual outcome of optical PK showed successful outcome, however, the survival rate decreased over time. The significant risk factors for graft failure should be cautiously evaluated before surgery.