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

Abstract

ObjectiveTo 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 analysisDMEK 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.ResultsA 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).ConclusionFor 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.

Glasses-Assisted 3D Display System–Guided Descemet Membrane Endothelial Keratoplasty Tissue Preparation

“…In DMEK tissue preparation, the influence of the staining time in the final outcome of the procedure and in the long-lasting viability of endothelial cells has always been a topic of discussion. 23 Multiple studies have tried to reduce the exposure to colorants. 24 In this study, we compared pairs of corneas aiming to reduce the differences in the results.…”

Effect of Descemet Membrane Endothelial Keratoplasty Graft Storage Time on Graft Elasticity

“…These findings are similar to previously published studies that explored the acceptable density of endothelial cell loss of prestripped, preloaded, and shipped DMEK grafts. [21][22][23] Several studies advocated that shipping of DMEK grafts with its endothelium trifolded inwards to prevent excessive endothelial cell loss compared with a conventional "endothelium-out" rolls (because of the possible contact between the graft and the vessel wall during the shipping process). 24,25 In this study, all DMEK grafts after preparation were let to scroll spontaneously, endothelium out, which did not seem to have a significant impact on cell loss.…”

“…These findings are similar to previously published studies that explored the acceptable density of endothelial cell loss of prestripped, preloaded, and shipped DMEK grafts. 21–23…”

Biomaterials and their impact on corneal transplantation and eye banking

“…To address this, eye banks can either partly strip DM and leave it adherent to a donor cornea or place it in a pre‐filled syringe for delivery. Reports confirm that preloaded scrolled tissue can be viable for up to 96 hours with minimal impact on corneal endothelial cell density and patient outcomes 6 …”

“…Reports confirm that preloaded scrolled tissue can be viable for up to 96 hours with minimal impact on corneal endothelial cell density and patient outcomes. 6 New biomaterials are being investigated to improve DMEK tissue preparation in eye banks and handling during surgery. Most ophthalmologists are familiar with ophthalmic viscoelastic devices that are essential to protect the corneal endothelium during cataract surgery.…”