Three‐quarter DMEK in eyes with glaucoma draining devices to avoid secondary graft failure

Abstract

Purpose To present a case series of a modified three‐quarter Descemet’s membrane endothelial keratoplasty (3/4‐DMEK) technique to treat pseudophakic bullous keratopathy in the presence of a glaucoma drainage device (GDD) tube in the anterior chamber by reducing the risk of donor endothelial damage due to absence of donor endothelial cells overlying the GGD tube area. Methods In this prospective case series, four eyes of three patients with stable glaucoma underwent 3/4‐DMEK surgery for pseudophakic bullous keratopathy after GDD insertion. The patients were followed up to 24 ± 2.5 months postoperatively. Results No intraoperative or postoperative complications were noted. The average central endothelial cell density (ECD) was 1093 ± 74 cells/mm2 at 12 months postoperatively, corresponding to an ECD decrease of 58 (±6)% as compared to preoperative values. Average best‐corrected visual acuity increased from finger counting before surgery to 20/60 (logMar 0.5) at 12 months after 3/4‐DMEK and remained stable up to 24 months postoperatively. All corneas remained clear at the last available follow‐up. Conclusion This case series demonstrates the technical feasibility of 3/4‐DMEK in eyes with pseudophakic bullous keratopathy in the presence of a GDD tube. The absence of a donor DM and donor cells above the silicone tube excludes direct tube contact with the graft. Longer term studies are needed to show the effect of this modified graft pattern and dimensions on transplant survival.

Graft survival of Descemet membrane endothelial keratoplasty (DMEK) in corneal endothelial decompensation after glaucoma surgery

“…Recently, a case series of three-quarter DMEK with a follow-up of 2 years was published by the Melles group. Four eyes received a 3/4 DMEK to avoid contact of donor cells above the silicon tube shunt [ 28 ]. The case series reported promising results, but more studies with a longer follow-up are still needed.…”

DMEK graft: One size does not fit all

“…Also, in case of eyes with previous GDD surgery, where DMEK has been reported as a feasible approach for the management of endothelial decompensation (Birbal et al, 2019; Lin et al, 2019; Oganesyan et al, 2021; Schrittenlocher et al, 2021; Sorkin et al, 2020), a smaller graft size may be beneficial, not only to better unfold and attach the graft, but also to avoid contact with the silicon tubes. Furthermore, ‘three‐quarter DMEK technique’ has been proposed recently in patients with GDD, which requires performing two perpendicular cuts during graft preparation, and then remove one quadrant to better fit in the eyes with GDD (Oganesyan et al, 2021).…”

“…(c) A small diameter (≤5 mm) graft would be technically challenging while preloading a DMEK graft with endo-in method as the graft will lose its orientation; however, endoout or a flat tissue can be delivered by injecting or using a bimanual pull-through technique if the tissue is marked or the orientation can be identified on a flat tissue with no graft scrolling. Also, in case of eyes with previous GDD surgery, where DMEK has been reported as a feasible approach for the management of endothelial decompensation (Birbal et al, 2019;Lin et al, 2019;Oganesyan et al, 2021;Schrittenlocher et al, 2021;Sorkin et al, 2020), a smaller graft size may be beneficial, not only to better unfold and attach the graft, but also to avoid contact with the silicon tubes. Furthermore, 'three-quarter DMEK technique' has been proposed recently in patients with GDD, which requires performing two perpendicular cuts during graft preparation, and then remove one quadrant to better fit in the eyes with GDD (Oganesyan et al, 2021).…”

Glaucoma in Patients With Endothelial Keratoplasty

“…50 Given the technical difficulties in graft insertion and unfolding for a thinner DMEK graft, novel graft preparation and insertion techniques, such as EndoGlide-DMEK and hybrid DMEK, have been introduced which may be useful in eyes with drainage devices. 91,92 Recently, Oganesyan et al 93 proposed a modified "3-quarter DMEK technique" for patients with prior drainage device where the 3/4-DMEK graft was positioned centrally and the missing 1/4-graft area was adjusted to the region of the tube. They reported that endothelial cell loss in the first postoperative year was similar to previous studies (range 49%-64%), with conventional DMEK.…”