Descemet's membrane endothelial keratoplasty with scraping without descemetorhexis (DMEK-SWD) in a failed penetrating keratoplasty

Purpose To introduce a novel treatment for a secondary failed penetrating keratoplasty (PK), termed Descemet's Membrane Endothelial Keratoplasty with endothelial scraping and without descemetorhexis (DMEK-SWD), through the presentation of two clinical cases. Observations In this prospective, single-center case series, two patients with previous PK for keratoconus developed endothelial decompensation, presenting with decreased visual acuity (Patient A: counting fingers; Patient B: 0.8 logMAR) and increased central corneal thickness (A: 735 μm; B: 653 μm). DMEK-SWD was performed using a 7.5-mm cell scraper through the temporal port to mechanically remove the host endothelium. A pre-stripped 7.5-mm DMEK graft was inserted using a standardized no-touch technique. Postoperative management included subconjunctival injections of gentamycin and dexamethasone. Graft attachment was maintained in both cases, although Patient B required single rebubbling procedure. Postoperative graft endothelial cell density (ECD), measured from confocal imaging (HRT3-RCM Cell Count), was 1,125 cells/mm2 at 12 months in Patient A and 1,544 cells/mm2 at 8 months in Patient B. At final follow-up (A: 18 months; B: 8 months), both patients showed improved best-corrected visual acuity (A: 0.2 logMAR; B: 0 logMAR) and reduced CCT (A: 496 μm; B: 505 μm). Conclusions and importance This pilot study demonstrates the feasibility of DMEK-SWD in treating failed PK, with a mean graft clearance time of 1.5 weeks for the two cases analyzed. The technique may represent a promising alternative to repeat full-thickness transplantation and supports further investigation in larger cohorts. Given the very small sample size and the incomplete availability of endothelial cell count data, these findings should be regarded as preliminary.