The aim of this study was to describe the challenges in Descemet membrane endothelial keratoplasty (DMEK) donor preparations and provide new strategies to achieve success.
A series of 263 consecutive DMEK preparation attempts by a novice surgeon during a corneal fellowship are described. In all cases, the Descemet membrane (DM) and the endothelium were peeled off from the donor cornea while it was submerged in corneal storage medium.
The success rate of preparing DMEK tissue was 99%. Three donor preparations of 263 (1.1%) could not be completed successfully because spots of strong adherence between the DM and the stroma caused multiple horseshoe-shaped tears (HST) to form in the DM. Lamellar splitting of the DM (“partial thickness HST”) preceded the formation of most HSTs. At least 1 HST occurred in 13% of donor preparations. In donor pairs (right and left corneas of 1 individual donor), if 1 cornea had any HSTs, there was a 60% chance that the contralateral cornea would have at least 1 HST. If 1 cornea had multiple HSTs, there was an 80% chance that the contralateral cornea would have at least 1 HST. Noting this trend, 3 donor corneas were returned to the eye bank unopened for other uses after their mates had multiple HSTs.
With appropriate techniques, DMEK donor preparation can be highly successful, even for a novice surgeon. When a donor develops multiple HSTs, we recommend not using the mate for DMEK because of a higher risk of encountering a preparation difficulty.