Abstract
Purpose :
To determine whether corneal endothelial cell (EC) numbers and/or metabolism is improved if deturgescence of donor corneas prior to graft preparation for Descemet’s Membrane Endothelial Keratoplasty (DMEK) is not performed.
Methods :
Human donor corneas unsuitable for clinical use and with appropriate research consent were used. Subtotal stripping of Descemet’s membrane (DM) was performed in 30 organ cultured corneas that had not undergone de-swelling but instead had been placed into fresh storage medium without dextran (KMI). Subtotal DM stripping was also performed in 30 control corneas had been placed in transport medium containing 5% dextran (KMII), as per eye bank routine. Of each group, 10 corneas were kept in culture for another 24 hours, 72 hours, or 120 hours, respectively. EC counts were documented before DM stripping and at the end of culture. Also, EC metabolism was assessed by detection of adenosine triphosphate at the end of culture.
Results :
Prior to DM preparation, no significant differences were detected with regards to mean EC density (cells/mm2) between the two experimental groups. At 24 hours after DM preparation, EC density was 2391 for corneas stored in KMI, and 2204 for corneas stored in KMII (p=0.003). This represents a mean relative EC loss of 12.4 % with dextran vs. 9.7 % without (p=0.04). At 72 hours, EC density was 2289 for KMI, and 1946 for KMII (p=0.004). This represents an EC loss of 23 % with dextran vs. 14 % without (p=0.009). At 120 hours, EC density was 2230 for KMI, and 2047 for KMII (p=0.14). This represents an EC loss of 22.7 % with dextran vs. 17.2 % without (p=0.14). At 120 hours after DM preparation, 6 of 10 corneas stored in medium containing dextran fell below a threshold of 2000 cells/mm2 vs. 1 of 9 corneas stored in medium without dextran (p=0.003). Lower ATP/protein ratios were observed if corneas had been stored in medium without dextran at 24 hours (p<0.001), 72 hours (p<0.001), and 120 hours (p=0.02) after DM stripping.
Conclusions :
If DM grafts are not used for transplantation immediately after preparation, media supplementation with dextran negatively affects EC viability and reduces EC density. Using non-deswollen corneas for DMEK surgery may serve to improve graft quality. Regardless of storage medium, graft storage time following pre-stripping should be kept to a minimum.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.