Dsaek Grafts Preservation In A Novel Hypothermic Storage Medium

To evaluate human DSAEK grafts during preservation in a novel corneal hypothermic storage medium under development phase XTRA·4 (AL.CHI.MI.A. SRL) at 2-8°C, in comparison to the control medium Eusol-C.

A total of twenty-nine (n=29) human corneas unsuitable for transplantation were recovered and included in this study. The corneas were stored in XTRA·4 (n=24), Eusol-C (n=5), at 2–8°C for 7–10 days. DSAEK lamellar grafts were prepared following the internal procedures of the EBs. The grafts were evaluated immediately after the cut and during lamellar storage for up to 72–96 hours at 2–8°C.

Endothelial Cell (EC) Density (ECD) was monitored using light microscopy. EC mortality and morphology scores were determined after Trypan Blue staining. Graft EC viability was assessed with Calcein-AM fluorescent dye. Optical coherence tomography (OCT) was employed to measure graft thickness (GT) immediately after the cut and during storage. The transparency of grafts stored in XTRA·4 (n=24) and Eusol-C (n=5) was evaluated using a lux meter.

DSAEK graft ECD was comparable among the groups both immediately after DSAEK graft preparation and after graft storage for up to 72–96 hours. No statistically significant differences in EC morphology score, EC mortality, and EC viability were observed, either immediately after the cut or at the end hypothermic storage. XTRA·4 medium maintained graft thickness unchanged for up to 72–96 hours of graft storage at 2–8°C, while the Eusol-C stored grafts showed a significant increase in thickness of +57±75 µm. Graft transparency was significantly higher in XTRA·4-stored grafts (68.2±5.0%) compared to Eusol-C stored grafts (55.7±6.1%) after 72–96 hours of storage.

DSAEK grafts were successfully obtained from human corneas stored in the new XTRA·4 medium at 2–8°C for 7–10 days. The grafts preserved in XTRA·4 medium at 2–8°C showed comparable results in terms of ECD, EC morphology, and EC viability to those preserved in control medium for up to 72–96 hours. However, XTRA·4 better maintained DSAEK graft thickness and transparency during storage at 2–8°C. These results provide new perspectives for achieving stable graft thickness during the transport of DSAEK grafts to operating theatres under hypothermic conditions.