[Effect of postmortem time on survival of corneal endothelium after cryopreservation]

In corneal cryopreservation and other preservation techniques, the donor tissue post-mortem time is believed to affect endothelial cell survival. In this study, porcine eyes were stored in a moist chamber at 4 degrees C for 2, 4, 8, 32, and 72 h. Then the corneas were subjected to cryopreservation. After thawing, a 24-h interval of organ culture was used as a viability test. The cell density of the central cornea and the percentage of Descemet's membrane denuded of endothelium were determined with vital staining and morphometric methods. Corneas stored 2-32 h before cryopreservation showed no difference in necrotic areas or cell density of surviving endothelium. Corneas stored 72 h before cryopreservation revealed no endothelial cell survival. We conclude that a post-mortem time of up to 32 h before corneal cryopreservation has no influence on endothelial cell survival.