Risk of Corneal Transplant Rejection Significantly Reduced with Descemet's Membrane Endothelial Keratoplasty

Abstract

To evaluate the relative risk of immunologic rejection episode in patients who underwent Descemet's membrane endothelial keratoplasty (DMEK), Descemet's stripping endothelial keratoplasty (DSEK), and penetrating keratoplasty (PK). Comparative case series. One hundred forty-one eyes treated with DMEK at Price Vision Group, Indianapolis, Indiana. The patients in the DMEK group were compared retrospectively with cohorts of DSEK (n = 598) and PK (n = 30) patients treated at the same center, with similar demographics, follow-up duration, and indications for surgery. The postoperative steroid regimen and rejection criteria were identical in the 3 groups. Kaplan-Meier survival analysis, which takes varying length of follow-up into consideration, was performed to determine the cumulative probability of a rejection episode 1 and 2 years after surgery. Proportional hazards analysis was used to determine the relative risk of rejection episodes between the 3 groups. P<0.05 was considered significant and calculated using the log-rank test. Rejection-free survival and cumulative probability of a rejection episode. The mean recipient age was 66 years (56% females and 94% Caucasian) and median follow-up duration was 13 months (range, 3-40) in the DMEK group. Fuchs' dystrophy was the most common indication for surgery (n = 127; 90%) followed by pseudophakic bullous keratopathy (n = 4; 4%) and regrafts (n = 9; 6.4%). Only 1 patient (0.7%) had a documented rejection episode in the DMEK group compared with 54 (9%) in the DSEK and 5 (17%) in the PK group. The Kaplan-Meier cumulative probability of a rejection episode at 1 and 2 years was 1% and 1%, respectively, for DMEK; 8% and 12%, respectively, for DSEK; and 14% and 18%, respectively, for PK. This was a highly significant difference (P = 0.004). The DMEK eyes had a 15 times lesser risk of experiencing a rejection episode than DSEK eyes (95% confidence limit [CL], 2.0-111; P = 0.008) and 20 times lower risk than PK eyes (95% CL, 2.4-166; P = 0.006). Patients undergoing DMEK had a significantly reduced risk of experiencing a rejection episode within 2 years after surgery compared with DSEK and PK performed for similar indications using the same corticosteroid regimen.