Abstract
Purpose :
To test whether pre-stripped, previously frozen DMEK grafts can be used as a substitute for freshly prepared tissue for surgical training.
Methods :
Twenty pre-stripped DMEK tissues (with S-stamps) were prepared according to standard protocols by trained eye bank technicians. Tissues were frozen and stored in Optisol-GS at -80°C. Thawed tissues were examined by DMEK trained cornea surgeons for tissue handling during graft preparation (trephination, lifting and peeling of graft from the stroma, and staining) and tissue behavior after transplantation into donor whole eyes (response to various surgical maneuvers used for graft unfolding and centration). The scroll width of previously frozen grafts was measured using a calibration grid and compared to previous studies performed using fresh tissue.
Results :
Tissue donor age ranged from 52-86 years, with preservation-to-frozen times ranging from 2-21 days. Tissue frozen-to-analysis times ranged from 6-57 days. S-stamps were readily observable on all tissues after they were thawed (n=20). Trained DMEK surgeons noted no differences between tissue handling of previously frozen DMEK grafts compared to fresh tissue. Grafts were successfully trephinated, stained with trypan blue, and prepared similarly to fresh tissue. DMEK graft scroll widths ranged from 1.11 – 2.30 mm (average=1.70 ± 3.4 mm), and were similar to previous reports examining fresh tissues. After injection into donor eyes, grafts were able to be unfolded and positioned using various surgical maneuvers that involved tapping on the cornea with cannulas or using gentle bursts of balanced salt solution. After the unfolded grafts were lifted into position using an air bubble, the S-stamp was visible to confirm proper graft orientation.
Conclusions :
Pre-stripped, previously frozen DMEK grafts can be used for surgical training as a substitute for fresh tissue. The availability of frozen pre-stripped tissues will improve accessibility for surgeon training.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.