Graft failure rate and complications after Descemet membrane endothelial keratoplasty in eyes with pre-existing glaucoma

PURPOSE: To evaluate the outcome of Descemet Membrane Endothelial Keratoplasty (DMEK) in eyes with pre-existing glaucoma. DESIGN: In this retrospective, observational case series we included data of 150 consecutive DMEKs in eyes with pre-existing glaucoma of 150 patients after excluding data of the second treated eye of each patient and of re-DMEKs during follow-up. Cumulative incidences of IOP elevation (IOP > 21 mmHg or ≥ 10 mmHg increase in IOP from preoperative value), post-DMEK glaucoma (need of an additional intervention due to worsening of the IOP), graft rejection, and graft failure rate were analyzed using Kaplan–Meier survival analysis. COX regression analysis was used to evaluate independent risk factors. RESULTS: The 36-month cumulative incidence of IOP elevation was 53.5% [95 CI 43.5–63.5%] and of post-DMEK glaucoma 36.3% [95 CI 26.3–46.3%]. Graft rejection occurred with a 36-month cumulative incidence of 9.2% [CI 95% 2.3–16.1]. None of the analyzed risk factors increased the risk for the development of graft rejection. The 36-month cumulative incidence of graft failure was 16.6% [CI 95% 8.4–24.8]. Independent risk factors for graft failure were the indication for DMEK “status after graft failure” (n = 16) compared to Fuchs’ dystrophy (n = 74) (p = 0.045, HR 8.511 [CI 95% 1.054–68.756]) and pre-existing filtrating surgery via glaucoma drainage device (GDD) (n = 10) compared to no surgery/iridectomy (n = 109) (p = 0.014, HR 6.273 [CI 95% 1.456–27.031]). CONCLUSION: The risks of postoperative complications (IOP elevation, post-DMEK glaucoma, graft rejection, and graft failure) in patients with pre-existing glaucoma are high. In particular, pre-existing filtrating surgery via GDD implantation—but not trabeculectomy—and DMEK after graft failure increase the risk of graft failure.