Five-year endothelial cell count post penetrating keratoplasty using internationally-transported corneal donor tissue

To study the five-year endothelial cell loss in patients having undergone penetrating keratoplasty (PKP) and who received corneal donor tissue from international eye banks.

This retrospective clinical study reviewed outcomes in 41 patients who underwent PKP at a tertiary eye center from February 2008 to July 2011. Standard PKP surgical technique was used for all patients, and graft tissue was supplied in all cases by eye banks in the United States of America. At five years after surgery, measurements were taken of endothelial cell density (ECD), coefficient of variation, hexagonality, donor's age, recipient's age, Death-to-preservation (DP), and preservation time (PT).

The recipients and donors median age was 30.0 years (24.0-35.5 years) and 59.0 years (53.0-61.0 years) respectively; the median DP and PT were 8.0hours.(6.0-10.0hours) and 10.0 days (9.0-11.5 days) respectively. At baseline, the ECD was 2398(2325-2525). At five years after surgery, all of the grafts were found to have survived; the median ECD was 1035 cell/mm² (693-1346 cell/mm²); the mean coefficient of variation was 35.2 ± 9.8%; and the mean hexagonality was 63.7 ± 24.3%. The overall ECD loss was 56% (95% CI: 50-62%); the ECD loss was 51.3% and 61.2% in corneas from donors younger and older than 60 years respectively (p = 0.056); likewise, the ECD loss was 52.6% and 61.0% in corneas with PT shorter and longer than 10 days respectively (p = 0.289). Although the difference in both cases was not statistically significant, it was clinically important (about 10%).

The ECD after five years in patients undergoing internationally-transported corneal tissue grafts incurred 56% loss; the donor's age and the PT were positively associated with ECD loss.