Endothelial cell death in organ-cultured donor corneae: The influence of traumatic versus nontraumatic cause of death

Abstract

• Background: Donors who have suffered a traumatic death are, on average, younger than those who have died from other causes, and the time from death to enucleation (DET) also tends to be shorter. Corneae obtained from such donors are therefore considered particularly suitable for grafting. One of the reasons for excluding a donor cornea from transplantation is the occurrence of endothelial cell necrosis during organ culture, and we investigated whether the incidence of this phenomenon bears a relationship to death by traumatic or nontraumatic means. • Methods: Data from 2125 donor corneae were collected using standardized evaluation protocols between January 1991 and December 1995 and included information on cause of death, age and DET, as well as endothelial cell loss and necrosis. Traumatic deaths were recorded in 346 cases, nontraumatic deaths in the other 1779 cases. Since differences in age (P = 0.006) but not in DET occurred within each of these groups, a more refined comparison, with matched data (< 35 years), was also undertaken. • Results: Forty (11.6%) of the 346 corneae derived from traumatic death donors manifested total or partial endothelial cell death in organ culture. The corresponding figure in the nontraumatic death group was only 105/1779 (5.8%;P = 0.0002). After matching for age, endothelial cell death during culturing was revealed in 18 (13.5%) of the 133 of the traumatic death corneae and in 3 (2.6%) of the 115 nontraumatic death ones (P = 0.004); the overall incidence of endothelial cell death (total or partial) during organ culture was 6.8% (145/2125). Endothelial cell loss during culturing of the 227 age-matched donor corneae which still had an intact endothelial monolayer at the end of the incubation period was 340 ± 388 cells/mm² in traumatic death corneae (n = 115) and 255 ± 318 cells/mm² in nontraumatic death ones (n = 112;P = 0.051). • Conclusion: Corneae obtained from traumatic death donors were more liable to undergo total or partial endothelial cell death during organ culture than were those procured from nontraumatic death ones. However, in corneae which survived the period of culture, there was no significant difference in endothelial cell loss between the two groups. Whilst the mechanism underlying this increased susceptibility of traumatic death corneae to cell death remains elusive, the data gleaned from this investigation nonetheless emphasize the potential importance of being able to perform meaningful in vitro viability tests on donor corneae; this is possible only under organ culture conditions.