Factors influencing the suitability of organ-cultured corneas for transplantation.

PURPOSE To assess the influence of donor and storage factors on the suitability of organ-cultured corneas for penetrating keratoplasty (PKP) using multifactorial regression analysis. METHODS Corneas (mean donor age, 57 years; standard deviation, 21 years) were stored by organ culture at 34 degrees C for up to 5 weeks (mean, 22 days; standard deviation, 6 days). The endothelium was assessed by light microscopy, and corneas with < 2200 cells/mm2 were considered unsuitable for PKP. RESULTS Of the 9250 corneas stored between 1992 and 1994, 59% were issued for PKP, 5% were discarded because of bacterial or fungal contamination, and 30% were unsuitable for PKP owing to endothelial deficiencies. Donor age had the strongest influence on suitability for PKP: > 80% of corneas from donors younger than 40 years of age were issued for PKP compared with only 45% of corneas from donors 80 years of age and older. There was an overall decline in the percentage of corneas suitable for PKP with increasing storage time, but the rate of this decline was inversely related to donor age. Cause of death and post mortem times to enucleation and to storage had only a small influence on suitability for PKP. CONCLUSIONS Criteria based on endothelial assessment rather than on donor age allow corneas from donors of all ages, stored by organ culture for extended periods, to be used for PKP. Organ culture also allows corneas with bacterial or fungal contamination to be identified and discarded before they are grafted.