Factors influencing endothelial cell density of corneas for transplantation.

Abstract

To evaluate factors affecting cornealendothelial cell density (ECD) under enucleation and preservation time studies at Eye Bank of the Federal District of Brazil. We conducted a case-control study collecting data from 1128 corneas where death-to-enucleation time and enucleation-to-preservation time were within 24h. Low cell count were those corneas with an ECD less than 2000cells/mm2 and high cell count was defined as those with ECD greater than 2000cells/mm2. We calculated the independent risk factors related to: cause of death, donor age, death-to-enucleation time, enucleation-to-preservation time and primary graft failure. Correlation analysis was used to assess which parameters influence ECD: death-to-enucleation time, enucleation-to-preservation time, average cell area (AVE), coefficient of variation and percentage of hexagonal cells. Of the total number of corneas, 1004 had ECD data and were selected for the study. 87.4% (n = 877) had high cell counts with 2699 ± 412cells/mm2. The mean donor age was 38.8 ± 16years. The most common causes of death were external causes (48.6%, n = 488). Longer times from death-to-enucleation, up to 24h were not associated with a decrease in ECD (OR 0.58; P = 0.44) or risk of graft survival (P = 0.74). Enucleation-to-preservation intervals greater than 12h showed increased risk of graft survival (P = 0.04). AVE was the main parameter for ECD (R2 = 0.96, P < 0.001). The overall graft survival rate was 98.2% (n = 761). Donors with 40years of age and above did not present a higher risk of graft survival (P = 0.09). We suggest that the maximum time from death-to-enucleation should be 24h, assuming the body has been refrigerated after 6h; and from enucleation-to-preservation time of 12h, followed by proper processing and cornea morphology examination.