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Updated: Apr 1, 2026
Corneal Donor Tissue Preparation for Descemet's Membrane Endothelial Keratoplasty
Published on: September 17, 2014
The S-stamp in Descemet Membrane Endothelial Keratoplasty Safely Eliminates Upside-down Graft Implantation
Peter B Veldman1, Philip K Dye2, Jeffrey D Holiman2
1Massachusetts Eye and Ear Infirmary, Boston, Massachusetts; Devers Eye Institute, Portland, Oregon.
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.
