Abstract
Purpose To assess the Descemet’s Membrane Endothelial Keratoplasty (DMEK) and Descemet’s Stripping Automated Endothelial Keratoplasty (DSAEK) graft preparation from human corneas preserved in a new corneal hypothermic storage medium (CHSM).
Methods Twenty (n=20) human donor corneas were stored either in CHSM (n=10) at 2-8°C, or in the standard organ culture medium at 31°C followed by deswelling medium (OC, n=10, control group) at 31°C. DMEK grafts were prepared using mechanical stripping technique after 5 to 14 days of storage. A novel calcein-based method to monitor and quantify endothelial viability during endo-out DMEK graft loading and ejection from an injector was developed and optimized.
In addition, human corneas were stored in CHSM (n=10) or in Eusol-C (EC, n=5, control group) at 2-8°C for a maximum of 10 days. DSAEK graft was prepared and stored (as precut DSAEK) in the same media for additional 4 days at 2-8°C to simulate post cut transport phase. Standard eye banks evaluation methods were used in order to monitor the graft quality during storage, before and immediately post-cut and after 2 and 4 days of transport simulation.
Results Endo-out DMEK graft were successfully obtained using the mechanical stripping technique in both CHSM and OC groups. Similar EC vitality change after DMEK graft preparation was observed both groups. Differently from the control group, in CHSM stored corneas the deswelling phase was skipped after the storage at 31°C. Moreover, CHSM- showed a significantly faster DMEK graft preparation compared to the control OC group.
Successful DSAEK grafts preparation and shipping simulation were achieved in corneas from both CHSM and EC groups, with similar endothelial quality parameters. Corneas stored in CHSM maintained unvaried graft thickness (GT) after DSAEK graft preparation,
Conclusions Naturally rolled DMEK endo-out grafts were successfully obtained from human corneas stored in the new CHSM medium at 2-8°C for up to 14 days with optimal preservation of corneal quality. Furthermore, the new media facilitated faster DMEK graft preparation compared to control organ culture and deswelling media.
Successful DSAEK preparation and shipping simulation was achieved using corneas stored in the new CHSM, maintaining unaltered endothelial quality parameters and GT.
