PURPOSE: To evaluate 4-year outcomes of Descemet membrane endothelial keratoplasty (DMEK) in eyes with previous glaucoma surgery. DESIGN: Retrospective, comparative case series. METHODS: Patients with previous trabeculectomy or glaucoma drainage device (GDD) implantation who later underwent DMEK (study group) were matched for follow-up duration with Fuchs dystrophy DMEK patients (control group). The minimum follow-up was 18 months. Primary outcomes included graft survival and rejection rates, and secondary outcomes included rates of detachment/rebubble, endothelial cell loss, best spectacle corrected visual acuity, intraocular pressure, and glaucoma medications/surgeries. Subgroup analysis compared eyes with and without a GDD. RESULTS: Ninety-four eyes of 91 patients were included. There were 51 eyes of 49 patients in the study group (GDD = 32 eyes, no GDD = 19 eyes) and 43 eyes of 42 patients in the control group. The mean follow-up was 37.9 +/- 15.2 and 33.8 +/- 13.5 months, respectively (P = .322). Graft survival probability of the study group at 12, 24, 36, and 48 months was 75%, 60%, 43%, and 27%, respectively, compared with a consistent 88% in the control group (P < .001). Survival curves of study subgroups (GDD and no GDD) were significantly lower than the control group (P < .001). Rejection rates in the study and control groups were 19.6% and 2.3%, respectively (P = .010). Endothelial cell loss in the study group was 12%-22% higher than the control group at 12, 24, 36, and 48 months (P = .049, P = .027, P = .200, and P = .004). CONCLUSIONS: In eyes with previous glaucoma surgery, DMEK has good early outcomes, but longer-term rejection and failure rates are high. Physicians and patients should be cognizant of the high likelihood of graft failure in this setting. (C) 2020 Elsevier Inc. All rights reserved.