THE HAMBURG SYSTEM OF CORNEAL PRESERVATION

We report on or experience with the evaluation, preservation and clinical grafting of corneal donor tissue. From a total of 2274 documented donor corneae about 1535 specimens were subjected to a corneal perservation procedure. Refrigerated storage of donor tissue has been completely replaced by corneal tissue culture. On the basis of the tissue culture techniques of Sperling, improved methods to culture and evaluate donor tissue were developed. Using organ-culture as a preservation system, post mortem intervals for donor tissue could be extended to 50 hours. Organ culture in this respect serves as a viability test, as the donor endothelium is examined before culture and again before grafting. Thus, primary graft failures caused by degenerative endothelial cell changes could be avoided. Using phase microscopy, we developed criteria for the prognostic evaluation of corneal endothelium without vital staining. From a total number of about 1101 clinical grafts, 712 were taken from corneal preservation and 389 from refrigerated globes. Since 1985 exclusively tissue-cultured donor corneae are used for transplantation. A clinical follow-up of 327 patients showed cultured tissue to be at least equal to "fresh" corneal grafts.