Purchase this article with an account.
Matthew Lloyd Haynie, Hideki Fukuoka, Natalie A Afshari; Optimal timing of DMEK graft procurement and the role of endothelial cells in the rolling of graft tissue. Invest. Ophthalmol. Vis. Sci. 2017;58(8):5673.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate the optimal time for Descemet membrane endothelial keratoplasty (DMEK) graft procurement in which adhesion strength of the Descemet membrane (DM) to the underlying stroma is minimized, facilitating viable graft procurement. Also to analyze the relationship between the tightness of DM graft rolling and the presence of endothelial cells.
Fresh rabbit eyes were refrigerated until 1, 5, or 21 days after harvesting, at which time the cornea was removed and placed in a vacuum block to undergo partial trephination. The force required to peel 1mm wide DM strips was measured in real-time as the change in weight of the system during the application of a vertical peeling force with forceps. Further data was obtained on day 5 eyes, which were stored in culture medium for days 6-10 and re-analyzed with the remaining portions of DM. Separate DM grafts (n=6) were obtained in a similar manner, placed in BSS and analyzed by OCT to determine the diameter of tissue rolling before and after removal of endothelial cells by a sterile swab. Unpaired T-test was used for statistical analysis.
There was a decrease in DM peeling force (p=0.008) between days 1 and 5 (556.04±111.76 and 324.30±96.4mg, respectively). However, there was no difference between days 5 and 21 (p=0.53). Interestingly, when day 5 eyes were placed in culture medium and re-analyzed at day 10, there was an increase in the force required for peeling (324.30±96.4 to 669.92±166.24mg, p=0.005). There was no significant difference in average rolling diameter of DM grafts before and after the removal of endothelial cells (257.9±131.1 and 249.8±126.6μm, respectively).
This data suggests that the adhesion strength of the DM to the underlying stroma is reduced several days after eye harvesting, at which time the lower DM adhesion strength could potentially facilitate DMEK graft procurement. Endothelial cells do not appear to play a significant role in the degree of rolling of DM graft tissue. Therefore, further studies are needed to determine the factors responsible for DMEK graft rolling.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.
This PDF is available to Subscribers Only