Purpose: Laboratory studies were performed to evaluate the histologic differences between the recipient bed after deep lamellar endothelial keratoplasty (DLEK) surgery and Descemet's-stripping endothelial keratoplasty (DSEK) surgery. Relevant new surgical strategies to prevent dislocation in DSEK surgery were initiated in our first 100 consecutive clinical cases.
Methods: Ten pairs of cadaver eyes had a DLEK in 1 eye and a DSEK in the fellow eye, and the posterior stromal surface was analyzed by scanning electron microscopy at x50 magnification. Based on the findings in these cadaver eyes, our DSEK procedure was modified to include surgical roughening in the peripheral recipient bed in 100 consecutive eyes. One hundred percent of these eyes were followed for at least 60 days after surgery to determine the rate of donor dislocation.
Results: In all 10 pairs of cadaver eyes, the DSEK stromal interface showed a smoother surface than DLEK eyes, without the presence of cut stromal fibrils. The DLEK surface was less smooth than the DSEK eyes, but with the presence of uniformly cut fibrils over the entire surface. Subsequent surgical modifications to the DSEK procedure to include scraping and roughening of the recipient peripheral bed in humans resulted in only a 4% (4/100) dislocation rate of the donor tissue into the anterior chamber. One of these 4 dislocated donors was seen on the first postoperative day and was the only primary graft failure in the series. The other 3 cases were fully attached on the first postoperative day with no interface fluid, but they dislocated later on postoperative days 2, 3, and 4.
Conclusion: The high rate of dislocation of the donor disc in DSEK may be caused by the absence of recipient stromal fibrils to initially bind to the donor stromal fibrils. Clinical success with a surgical technique of selectively scraping the peripheral recipient bed to promote donor edge adhesion (while leaving the central bed untouched for vision) may aid in the prevention of donor dislocation in DSEK surgery. Reduction of dislocation in DSEK surgery has also been associated with a reduced rate of iatrogenic primary graft failure (PGF) to 1%.