Abstract
Purpose:
Descemet’s membrane endothelial keratoplasty (DMEK) has emerged as the superior technique for endothelial keratoplasty (EK) in routine cases. One barrier to its implementation compared to earlier forms of EK is the difficulty in stripping the donor tissue for transplantation. Currently, peeling is sometimes performed by the eye bank and sometimes by the surgeon. The purpose of this study is to determine donor tissue characteristics which contribute to longer peeling times or tissue tears during DMEK peeling.
Methods:
This is a retrospective case series. The clinical data including donor age, gender, age of tissue, contralateral eye data, peel time, and peel complications of 116 consecutive DMEK donor tissue between February and September 2013 were compared. All tissues were prepared by a single surgeon using the SCUBA technique.
Results:
Mean peel time was 10.1±3.3 minutes (range 6-24 minutes). Tears were noted in 7 cases (6%) and occurred more commonly with longer peel times. Donor gender and post-mortem day of peeling did not have any statistical significance for peeling time or tear rate although only tissue under 7 days old was used (P < 0.05). Interestingly, tissue from donors greater than 65 had slightly faster peel times, but this difference did not reach statistical significance (≤65 = 11.0 ±4 minutes; >65 9.3±3.1 minutes (P = 0.07) but had equal rates of graft tears (6%). Most importantly however, there was a strong correlation between peel times for the two eyes from the same donor (r = 0.78) and the risk of a tear during peeling in the second eye was much greater if the first graft also had a tear during preparation (odds ratio = 7.2).
Conclusions:
Although the qualities of the ideal DMEK graft are likely similar to those of DSAEK grafts, exclusion of the contralateral eye tissue when there was difficulty in graft peeling for the first eye may prove to be a unique quality of DMEK donor tissue. Tissue from donors over age 65 may prove to peel faster, and this advantage may be related to deposition of the posterior non-banded layer of Descemet’s membrane over time.
Keywords: 481 cornea: endothelium