Validation of an endothelial roll preparation for Descemet Membrane Endothelial Keratoplasty by a cornea bank using "no touch" dissection technique.

Abstract

Descemet Membrane Endothelial Keratoplasty (DMEK) selectively replaces the damaged posterior part of the cornea. However, the DMEK technique relies on a manually-performed dissection that is time-consuming, requires training and presents a potential risk of endothelial graft damages leading to surgery postponement when performed by surgeons in the operative room. To validate precut corneal tissue preparation for DMEK provided by a cornea bank in order to supply a quality and security precut endothelial tissue. The protocol was a technology transfer from the Netherlands Institute for Innovative Ocular Surgery (NIIOS) to Lyon Cornea Bank, after formation in NIIOS to the DMEK "no touch" dissection technique. The technique has been validated in selected conditions (materials, microscope) and after a learning curve, cornea bank technicians prepared endothelial tissue for DMEK. Endothelial cells densities (ECD) were evaluated before and after preparation, after storage and transport to the surgery room. Microbiological and histological controls have been done. Twenty corneas were manually dissected; 18 without tears. Nineteen endothelial grafts formed a double roll. The ECD loss after cutting was 3.3% (n=19). After transportation 7days later, we found an ECD loss of 25% (n=12). Three days after cutting and transportation, we found 2.1% of ECD loss (n=7). Histology found an endothelial cells monolayer lying on Descemet membrane. The mean thickness was 12±2.2µm (n=4). No microbial contamination was found (n=19). Endothelial roll stability has been validated at 3days in our cornea bank. Cornea bank technicians trained can deliver to surgeons an ECD controlled, safety and ready to use endothelial tissue, for DMEK by "no touch" technique, allowing time saving, quality and security for surgeons.