Viability of preloaded Descemet membrane endothelial keratoplasty grafts with 96-hour shipment

Abstract

Objective: To assess feasibility and compare the effects of 96-hour shipment of Descemet membrane endothelial keratoplasty (DMEK) grafts as a scroll or a tri-fold on cell viability.

Methods and analysis: DMEK grafts were prepared at the Rocky Mountain Lions Eye Bank. Twenty pre-stripped DMEK grafts, paired from 10 donors, were either tri-folded in an endothelium-in configuration using microforceps and loaded into a plastic Treyetech cartridge, or suctioned in a scrolled endothelium-out configuration into a modified Jones Tube. Grafts were shipped via FedEx to a secondary location and back for 48 hours each way, resulting in a total shipping time of 96 hours. After shipping, grafts were removed from inserters onto glass slides and unfolded using viscoelastic with endothelium facing upwards. Calcein-AM stained grafts were imaged with a fluorescent microscope and endothelial cell loss (ECL) was measured using trainable segmentation in Fiji by a masked grader.

Results: A total of 20 grafts were shipped for 96 hours, split between preloaded tri-folded (n=10) and preloaded scrolled (n=10) tissues. No significant difference in ECL was observed across groups after prolonged shipping (14.8% vs 13.7% ECL respectively, p=0.68).

Conclusion: For preloaded DMEK after 96 hours, both scrolled and tri-folded tissue demonstrated clinically acceptable levels of ECL. The data suggest a wider window of time for endothelial cell viability and is promising for the prospect of international shipment of preloaded grafts.

Keywords: DMEK; cornea; descemet membrane endothelial keratoplasty; eye (tissue) banking; preloaded; trifolded.

Figure 1

Graft configuration in Jones Tube and Treyetech cartridge. Endothelium is represented by the chequered pattern and stroma is represented by the solid pattern. (A) Grafts in the Jones Tube are in a scrolled endothelium-out configuration. (B) Grafts in the Treyetech cartridge are in a tri-folded endothelium-in configuration.

Figure 2

Representative images of stained and segmented grafts after shipping and removal from cartridges. (A) Fluorescent image of donor 2’s graft after immediate removal from the modified Jones Tube and staining. (B) Segmented image of donor 2’s graft, showing cells classified as viable in red. Measured endothelial cell loss (ECL) is 11.4%. (C) Fluorescent image of donor 7’s graft after immediate removal from the Treyetech cartridge and staining. (D) Segmented image of donor 7’s graft, showing cells classified as viable in red. Measured ECL is 10.8%.