Effect of Donor Graft Quality on Clinical Outcomes After Penetrating Keratoplasty for Keratoconus

PURPOSE: To evaluate the effect of donor and eye bank characteristics on graft rating and clinical outcomes after penetrating keratoplasty (PK) for keratoconus. METHODS: This retrospective interventional case series included 252 keratoconic eyes which underwent PK. Donor data included age and sex, cause of death, death-to-preservation time, preservation-to-surgery time, epithelial and stromal status, endothelial cell density (ECD) and morphology, and graft rating. Postoperative outcomes included visual acuity, refractive error, epithelial problems, suture-related complications, graft rejection, and graft transparency. Multivariate regression analysis assessed correlations between donor and eye bank characteristics and graft quality, and postoperative outcomes. RESULTS: Mean recipient and donor age was 29.7 ± 10.0 and 26.2 ± 8.8 years, respectively and mean follow-up period was 66.7 ± 38.5 months. Death-to-preservation time was significantly associated with the presence of graft epithelial sloughing (P = 0.005) and stromal cloudiness (P < 0.001). Donor age significantly influenced ECD (P = 0.02), mean cell area (P = 0.04), and hexagonality (P = 0.01). The presence of epithelial defects on postoperative day 1 correlated significantly with death-to-preservation time (P = 0.004). Graft stromal edema on postoperative day 1 was significantly associated with graft epithelial sloughing (P < 0.001). Postoperative visual and refractive outcomes, complications, and graft survival were not correlated with any donor or eye bank factors. CONCLUSION: Donor and eye bank variables affected the quality of donor corneas and early postoperative course. However, their long term effect on clinical outcomes, complications, and graft survival were insignificant.