ABSTRACT
Purpose
To investigate the optimal time for Descemet membrane endothelial keratoplasty (DMEK) graft peeling, and to analyze the rolling properties of endothelial denuded grafts in a rabbit eye model.
Materials and Methods
The vertical peeling force required to peel 1 mm wide Descemet membrane (DM) strips, was measured as the change in weight of the system during force application in a rabbit model. Twenty-one rabbit corneoscleral rims were stored in phosphate-buffered saline (PBS) at 4°C, and force analysis was performed at days 1, 5, or 21 after harvesting. After half of the strips of day 5 corneas were peeled and analyzed, the rims were moved to Optisol GS at 4°C, and the remaining strips were peeled off for force analysis at day 10. Separate DM grafts (n = 7) were analyzed by intraoperative optical coherence tomography (OCT) to determine the tissue rolling diameter before and after removal of endothelial cells by a swab. Unpaired t-test was used for statistical analysis.
Results
There was a decrease in DM peeling force (p = .008) between days 1 and 5 (556.04 ± 111.76 and 324.30 ± 96.4 mg, respectively), and no difference between days 5 and 21 (p = .53). Peeling force for day 5 corneas placed in Optisol was higher at day 10 (324.30 ± 96.4 to 669.92 ± 166.24 mg, p = .005). The average rolling diameter of DM grafts was similar before and after the removal of endothelial cells (257.9 ± 131.1 and 249.8 ± 126.6 μm, respectively).
Conclusions
DMEK Graft procurement could be potentially facilitated by lower DM-stromal adhesion strength at day five after obtaining corneoscleral rims, in a rabbit eye model. Time in the storage medium may influence adhesion strength. Endothelial cells do not appear to play a significant role in the rolling diameter of DM grafts.
Acknowledgments
None
Conflicts of interest
No commercial relationships. No conflicting relationship exists for any author.
Decleration of interests
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.