This investigation assessed the long-term safety and efficacy of repeat penetrating keratoplasty (PK) procedures.
Researchers retrospectively examined outcomes from 992 consecutive patients that underwent PK. Ninety-six cases with at least 3 years of follow-up underwent repeat PK. Donor graft survival rate, BSCVA, endothelial cell density (ECD) and complications after repeat procedures were studied.
Donor graft survival rate after repeat PK was 90.6% at 1 year, 75% at 3 years and 64% at 5 years. Survival rate according to the number of repeat penetrating keratoplasties did not differ between those who had 1, 2, 3 or 4 repeat PKs.
Multivariate analysis of survival showed patients with previous glaucoma surgery (HR 6.7; P<0.01) or an episode of rejection (HR 5.6, P<0.01) were at higher risk factors for graft failure in repeat PK. Graft failure after repeat PKs were unrelated to age, use of oral cyclosporine, peripheral anterior synechiae, neovascularization, use of IOP-lowering medicines, and donor ECD of less than 3,000cells/mm2.
This study was limited by the small number of patients, the length of follow up and its retrospective nature. Systemic steroids and immunosuppressive agents were used in a large number of patients but were not standardized for every repeat keratoplasty. Patients with severe ocular surface disease were excluded. DSEK as an alternative to repeat PK for graft failure was not studied.
The authors highlight that previous studies indicate a poorer prognosis with repeat PK. This is in contrast to the results of this study which demonstrated that even multiple repeat grafts tended to have a similar survival curve. This study show that repeat PK can be considered a good surgical option for patients with prior failed corneal grafts, but that graft survival is reduced in patients who have underwent glaucoma surgery or had previous rejection episodes.