MAR 13, 2014
This retrospective, 200-eye study of patients undergoing Descemet membrane endothelial keratoplasty (DMEK) found that graft adherence was markedly better when the host descemetorhexis was larger than the endothelial graft.
A major hurdle in surgeon adoption of DMEK is the high rate of detachment. This study could represent a major advance in DMEK technique in terms of decreasing the rate of donor detachment if these results are corroborated by other surgeons.
Subjects were 51 patients (53 eyes) who underwent DMEK for Fuchs’ endothelial dystrophy performed by the same surgeon at a university hospital in Germany. In Group A, the diameter of the descemetorhexis was approximately 10 mm, resulting in a peripheral 1-mm zone of denuded stroma between the graft and the host’s Descemet membrane. In Group B, the diameter of the descemetorhexis was approximately 6 mm, resulting in a peripheral 1-mm zone of overlap between the graft and the host’s Descemet membrane.
At four days postop, Group A had a 33 percent rate of detachment with 6.7 percent requiring rebubbling, compared to a 78 percent rate of detachment with 30.4 percent requiring rebubbling in Group B. The mean extent of graft detachment was 0.6 and 2.8 clock hours in groups A and B, respectively (P < 0 .001), four days after surgery.
The authors postulate that the host Descemet’s membrane negatively impacts donor Descemet’s membrane adherence, specifically the adhesive protein keratoepithelin, which is blocked if the host Descemet’s membrane remains. Interestingly, the authors found no corneal edema in the group with the larger descemetorhexis (Group A) in stromal areas not covered by the host or donor Descemet’s membrane.