Abstract
Purpose :
To examine tissue quality resulting from manipulation to form double scroll (DS) DMEK grafts during and after graft preparation.
Methods :
DS during preparation: Grafts prepared from 10 pairs of donor corneas (age 39-66) were floated in BSS and allowed to spontaneously scroll. Controlled bursts of BSS were used to promote DS formation in one member of each pair. Grafts were subsequently stained with Calcein-AM, imaged, and analyzed for endothelial cell loss (ECL) by FIJI segmentation. Cell loss from manipulated and unmanipulated mate grafts was compared using unpaired Student’s t-test. Double scrolling preloaded grafts: Grafts from 18 pairs of donor corneas (split into ‘young’ (age 48-64) and ‘old’ (age 66-80) cohorts) were prepared and loaded into a Straiko modified Jones tube. One member of each pair was induced to DS by applying repeated push-pull action on a BSS-filled syringe attached to the injector tube. Manipulated and unmanipulated mate grafts were analyzed and compared as described above.
Results :
An eye bank processing technician was able to successfully form a DS during graft preparation in 9/10 attempts. There was no difference in ECL in manipulated compared to unmanipulated mate grafts (15.2%±3.3% vs 15.2%±4.4%, P=0.99). For preloaded DMEK grafts, the old cohort could form a DS in 9/9 attempts while the young cohort could only form DS in 6/9 attempts. The additional tissue manipulation resulted in a significant difference in ECL in the old cohort (manipulated: 17.4%±3.5% vs unmanipulated: 13.0%±4.2%, P=0.03), but not the young cohort (15.5%±4.4% vs 13.0%±4.5%, P=0.24).
Conclusions :
DS DMEK grafts can be successfully formed during or after graft preparation. In older donor grafts, additional manipulation required to form a DS results in increased ECL; but this cell loss is within the acceptable range for transplant tissue. In younger donor grafts, additional manipulation using either technique does not result in increased ECL. For older donor grafts, surgeons should weigh the advantage of an easily opened DS against the risk of higher ECL. These two techniques may encourage the use of younger donor grafts, as neither technique produced an increase in ECL in younger donors. These techniques may also prove useful with both young and old donor tissue in more complex surgical cases, as they yield easily opened DS grafts that may reduce the difficulty of DMEK surgery.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.