To determine the feasibility of preloading endothelial tissues for Descemet membrane endothelial keratoplasty (DMEK).

Laboratory investigation.

setting: Institutional. participants: Twenty human donor corneas unsuitable for transplantation with endothelial cell density in a range of 1600–2700 cells/mm². Intervention: The endothelium was punched, stripped (8.5 mm diameter) and manually tri-folded with the endothelial side inward. The excised membranes were gently moved in a 2.2 intraocular lens (IOL) cartridge and pulled further in the funnel using 25 G end-grasping forceps. The cartridge was filled with transport media (TM) (sealed at its funnel and back entrance with a stopper) and the tissue was preserved for 4 days at room temperature in the bottles containing TM. main outcome measures: Success rate of preparation, processing time, endothelial cell loss (ECL), and active metabolism.

The tissues were peeled and loaded successfully in all cases. Average stripping and loading time was 20 and 4.5 minutes, respectively. ECL after preservation was 4.35% with 3.55% (± 5.89%) mortality and 7.80% (± 14.12%) uncovered areas. A total of 0.55 (± 0.26) mg/mL of glucose was consumed by the cells showing active metabolism.

Tri-folded (endothelium-in) DMEK grafts can be preloaded using TM in an IOL cartridge and stored up to 4 days with limited endothelial damage. Direct injection of TM should be avoided because of the presence of bovine serum, but the tissue can be washed using balanced salt solution and gently injected. Alternatively, the graft can be easily delivered using a bimanual pull-through technique. Preloading DMEK grafts will simplify the surgery with reproducibility, reduced surgical time, and reduced tissue wastage, cost, and logistical requirements.