The S stamp in Descemet Membrane Endothelial Keratoplasty Safely Eliminates Upside down Graft Implantation.
PURPOSE To present 6 month clinical outcomes from a series of 165 consecutive Descemet membrane endothelial keratoplasty (DMEK) procedures before and after the introduction of a novel stromal sided S stamp preparation technique that has decreased the incidence of iatrogenic primary graft failure by eliminating upside down grafts. DESIGN Retrospective nonrandomized comparative case series. PARTICIPANTS We included 165 consecutive eyes that had undergone DMEK surgery for Fuchs' or pseudophakic bullous keratopathy. These cases were divided into 2 cohorts: the first cohort comprised 31 cases that used unstamped tissue before the S stamp was introduced, and the second cohort comprised 133 cases after the S stamp was incorporated into the standardized technique. A single unstamped DMEK case was performed after the introduction of the S stamp for a total of 32 unstamped cases. METHODS Donor materials were prepared at a single eye bank using a standardized technique, which subsequently incorporated the addition of a dry ink gentian violet S stamp to the stromal side of Descemet membrane. All surgeries were performed at a single clinical site by 5 surgeons (2 attending surgeons and 3 fellows) Two of the 165 DMEK cases were performed for pseudophakic bullous keratopathy (2 cases, 1 in each cohort) and the remaining cases were for Fuchs' endothelial dystrophy. Primary outcome measures were assessed at 6 months and maintained in a prospective institutional review board approved study. MAIN OUTCOME MEASURES We analyzed the 6 month endothelial cell density, incidence of iatrogenic primary graft failure, upside down graft implantation, and rebubble events. RESULTS The S stamp eliminated upside down graft implantations (0/133 S stamped vs 3/32 unstamped) and did not significantly alter 6 month endothelial cell loss (31+ 17% S stamped vs 29+ 14% unstamped; P 0.62) or frequency of rebubble (17/133 S stamped vs 1/32 unstamped; P 0.20) CONCLUSION The incorporation of a stromal sided S stamp eliminates iatrogenic primary graft failure owing to upside down implantation of DMEK grafts, without adversely affecting early postoperative complications or 6 month endothelial cell loss.
Ophthalmology