Abstract
Purpose:
Analysis of the influence of donor and recipient factors on five-year graft survival for validation of the quality standards applied in the CTS Eye Banks in Bristol and Manchester.
Methods:
Corneas stored by the CTS Eye Banks between April 1999 and March 2005 were included in the study. A logistic regression analysis was carried out to determine the influence of donor factors on the suitability of corneas for penetrating keratoplasty (PK). Survival data were analysed by univariate methods (Kaplan-Meier survival) and multiple regression (Cox proportional hazards), as appropriate for influence of donor factors on 5-year graft survival.
Results:
Suitability for PK (n=7107). Donor age (p<0.0001) and storage time in organ culture (p<0.0001) were the principal factors affecting suitability. Five-year graft survival (n=3014). Graft survival was predominantly influenced by the indication for PK. Kaplan-Meier five-year survival estimates ranged from 91% (95%CI 89 to 93) for keratoconus to 57% (95%CI 53 to 60) for bullous keratopathy. Among the other pre- and postoperative factors that had a significant impact, allograft rejection was a major risk factor for failure (HR 2.6, 95%CI 2.1 to 3.3, p<0.0001).
Conclusions:
While donor factors, in particular age and storage time in organ culture, influenced the suitability of corneas for PK, these and other factors such as post-mortem times to enucleation and processing had no effect on five-year graft survival. The indication for PK and other recipient factors (i.e., preoperative risk factors and postoperative complications) were the main predictors of graft failure. These data therefore support the donor and cornea selection criteria applied by the CTS Eye Banks in the UK; namely, no upper donor age limit, death to enucleation times up to 24 hours, storage by organ culture for up to four weeks, and a minimum endothelial cell density for PK of 2200 cells/sq.mm
Keywords: 479 cornea: clinical science