DMEK graft: One size does not fit all

Abstract

Descemet membrane endothelial keratoplasty (DMEK) is a popular procedure for the treatment of corneal endothelial diseases mainly targeting Fuchs endothelial corneal dystrophy (FECD) and pseudophakic bullous keratopathy (PBK).Although DMEK has multiple advantages, it is challenging in terms of graft preparation and delivery. One of the crucial factors of DMEK graft preparation is determining the size of the graft. Evaluating risks and benefits of transplanting larger or smaller grafts compared with the descemetorhexis performed following a standard DMEK procedure thus becomes important. Advanced techniques like pre-loaded DMEK requires pre-selection of graft diameter without physical examination of the eye making it more challenging. Therefore, recognizing the benefits of graft size and the number of transplanted endothelial cells becomes essential.Smaller DMEK grafts have been preferred and accepted for grafting. Larger diameter grafts have advantages but can be challenging due to higher detachment rates. We thus aim to review the challenges of preparing and delivering DMEK tissues with small or large diameter based on selected descemetorhexis area, discuss the outcomes based on different graft sizes, highlight related complications and suggest which cases may benefit from adopting smaller or larger graft size.

Porcine Cornea Storage Ex Vivo Model as an Alternative to Human Donor Tissues for Investigations of Endothelial Layer Preservation

“…The analysis of the 8-mm central endothelial area, corresponding to the standard DMEK graft diameter, 37 showed a difference in EC mortality localization between the two species. Specifically, while no difference was observed in human corneas, porcine corneas showed significantly higher EC mortality in the central area compared to the peripheral area after 7 and 14 days of hypothermic storage.…”

Preloaded DMEK With Endothelium Outward: A Multicenter Clinical Study Using DMEK Rapid Device

“…Different graft sizes have been used by different centers depending on the requirement. 21 In this study, we purposely selected a standard graft size (8.25 mm diameter) to reduce the variability between the surgeons in handling a DMEK graft. Rebubbling rates have been reported in a range of 6% to 40%.…”

Descemet membrane endothelial keratoplasty graft detachments in superior versus temporal approach

“…1,[6][7][8] Several risk factors for graft detachment have been reported in literature, including intraoperative complications, recipient age, type and volume of anterior chamber (AC) tamponade, centration of the graft, combined DMEK and cataract surgery, surgeon experience, and the use of Eye bank prepared DMEK tissues. 6,[9][10][11][12][13][14][15][16] However, only one study so far evaluated the impact of corneal incision location on the risk of DMEK graft detachment. 17 Therefore, in this study we retrospectively analyzed the outcomes and rate of re-bubbling in eyes which underwent DMEK surgeries, comparing superior with temporal incision approach.…”

“…Several risk factors for graft detachment have been reported in literature, including intraoperative complications, recipient age, type and volume of anterior chamber (AC) tamponade, centration of the graft, combined DMEK and cataract surgery, surgeon experience, and the use of Eye bank prepared DMEK tissues. 6,9–16 However, only one study so far evaluated the impact of corneal incision location on the risk of DMEK graft detachment. 17…”