Authors: Tanguy Boutin, Nir Sorkin, Adi Einan Lifshitz, Zale Mednick, Mahmood Showail, Armand Borovik, Clara C. Chan, David Rootman
Author Disclosure Block: T. Boutin: None. N. Sorkin: None. A. Einan Lifshitz: None. Z. Mednick: None. M. Showail: None. A. Borovik: None. C.C. Chan: None. D. Rootman: None.

Abstract Body: 

Purpose: To present the outcome of Descemet Membrane Endothelial Keratoplasty (DMEK) in eyes that have a previous trabeculectomy or a glaucoma drainage device (GDD).

Study Design: retrospective case series

Methods: A retrospective medical chart review of patients that had previously undergone trabeculectomy or GDD implantation, who later underwent DMEK between 2013 and 2017 at the Toronto Western Hospital was done. Twenty-seven eyes of 27 patients with a minimal postoperative follow-up of 6 months were included in the analysis. The indications for DMEK were: Fuchs endothelial dystrophy (2), Pseudophakic bullous keratopathy (12), Iridocorneal endothelial syndrome (2), failed grafts: penetrating (4), DSAEK (5), DMEK (2). All eyes included had previous glaucoma surgeries: GDD (12 patients), trabeculectomy (9 patients), trabeculectomy and GDD (4 patients), trabeculectomy and Minimally Invasive Glaucoma Surgeries (MIGS) (2 patients).

Results: Mean best-corrected visual acuity (BCVA) improved significantly from 1.58 ± 0.62 logMAR (20/760 Snellen) preoperatively to 0.88 ± 0.55 logMAR (20/150 Snellen) at 6 months (p<0.0001). At 6 months of follow up, the percentage of eyes that reached 20/50 or better was 41 % and 20/200 or better was 78%. Mean donor endothelial cell density (ECD) was 2776 ± 202 cells/mm2 preoperatively and 1875 ± 451 cells/mm2 at 6 months postoperatively (p<0,001). This corresponds to a mean percentage cell loss of 32.4%. Post-operatively, 7 cases out of the 27 (26%) had a graft detachment of which 5 required rebubbling (19%). All were attached following rebubbling. We had one case of primary failure and two of failure in the first year. Of the 27 grafts, one had a rejection after 2 months and another one after 7 months. Of the 27 patients, 16 had a previous GDD implantation. Of those, only 30% reached 20/50 or better BCVA and 48% 20/200 or better at 6 months showing more limited visual improvement in advanced glaucoma patients with DMEK.

Conclusions: While more challenging to do, DMEK may be successfully performed in eyes with a GDD or previous trabeculectomy.