Abstract
Purpose :
Historically, donor corneas have been required to have a central clear zone to be deemed suitable for corneal transplantation. Even in the age of lamellar surgery, surgeons have continued to expect that this criterion is fulfilled, with surgeons requiring an 8 mm central clear zone for pre-stripped DMEK to accommodate placement of a 7.5-8 mm punch at the time of surgery. For eye bank prepared pre-punched or pre-loaded grafts, the clear zone does not have to be completely contained in the central 8 mm because eye bank technicians can offset the punch to accommodate peripheral pathology such as prior surgical scars. The purpose of this study was to ascertain whether incorporating pre-punched and pre-loaded DMEK processing steps into an eye bank’s operations can increase its DMEK donor pool by giving technicians the option of offsetting the donor punch.
Methods :
We performed a retrospective review of corneas recovered and processed for DMEK by a single eye bank between March 2017 – October 2018. We examined the number of corneas evaluated by eye bank technicians to be suitable for DMEK processing only if they were pre-punched or pre-loaded with an offset clear zone graft. These corneas would otherwise fail the conventional central clear zone criterion for pre-stripped grafts.
Results :
A total of 2607 corneas were rated suitable for DMEK during the study period; 1106 were processed for DMEK with the remainder being processed for other types of transplantation. Of the 2607 DMEK suitable corneas, 62 corneas (2.4%) would have failed the conventional central clear zone criterion during this period but were determined suitable for pre-punched or pre-loaded DMEK processing according to the offset criterion. Of these corneas, 40 were processed for DMEK as pre-punched or pre-loaded DMEK grafts. Thus, 3.5% (40/1146) of transplanted grafts included in this study were utilized for DMEK because it was possible to offset, pre-punch, and pre-load grafts at the eye bank.
Conclusions :
Incorporating pre-punching, with or without pre-loading, may increase the DMEK donor pool by at least 2.4% by enabling technicians to ‘fit’ a DMEK punch within an offset clear zone. These additional options give eye banks more flexibility for selecting DMEK suitable corneas to support the increased popularity and adoption of DMEK.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.