Influence of Descemet Membrane Endothelial Keratoplasty Graft Preparation Patterns on Postoperative Clinical Outcome

Purpose:The aim of this study was to quantify preparation difficulties and complications during DMEK graft preparation and their influence on clinical outcome.Methods:A retrospective evaluation of 214 consecutive DMEK surgeries from the prospective Cologne DMEK database was performed between July 2018 and December 2019. Preparation conditions (such as central and peripheral adherences, tissue fragility, and Descemet membrane splitting) were quantified and divided into 3 groups: easy, difficult, and very difficult preparation. At follow-up (3, 6, and 12 months after DMEK), best spectacle-corrected visual acuity, endothelial cell count (ECC), and rebubbling rates were evaluated and compared between groups.Results:An easy preparation was possible in 41.6% of cases (group 1, n = 89), a difficult preparation of the DMEK graft occurred in 30.8% (group 2, n = 66), and a very difficult preparation occurred in 27.6% (group 3, n = 59). There was no difference between groups for best spectacle-corrected visual acuity at 3, 6, and 12 months (P = 0.179, P = 0.325, and P = 0.682, respectively) or for ECC at 3 and 6 months (P = 0.537 and P = 0.606, respectively). Only at 12 months, the ECC was slightly significant between groups (P = 0.045). Regarding the rebubbling rate, there was no difference (P = 0.585). 17.9% of eyes from group 1, 25.7% of eyes from group 2, and 23.7% of eyes from group 3 received at least 1 rebubbling.Conclusions:These data suggest that difficult preparation conditions do not lead to any worsening of visual acuity or rebubbling rate in the 1-year outcome after DMEK. The endothelial cell density at 12 months showed slightly poorer results in the cases of very difficult preparation.