Repeat corneal transplantation in Auckland, New Zealand: indications, visual outcomes and risk factors for repeat keratoplasty failure

IMPORTANCE: In New Zealand, repeat keratoplasty has become the second leading indication for corneal transplantation. BACKGROUND: To report the indications, outcomes and survival of repeat keratoplasty and evaluate the risk factors for graft failure. DESIGN: Retrospective study in a public corneal service. PARTICIPANTS: Two hundred nineteen patients undergoing 279 repeat keratoplasty procedures during 1991-2017. METHODS: The New Zealand National Eye Bank prospectively collects data on all corneal transplants. This was utilized to identify patients undergoing repeat keratoplasty in Auckland. Clinical records were retrospectively reviewed. MAIN OUTCOME MEASURES: Graft survival and visual outcome. RESULTS: The repeat keratoplasty technique was penetrating keratoplasty (PK) in 242 cases (86.7%) and endothelial keratoplasty in 37 (13.3%). The most common primary indication was keratoconus (46.6%). The most common indication for repeat keratoplasty was endothelial decompensation (37.6%). For PK performed as a repeat keratoplasty, the median survival in years was 12.0 for first, 3.5 for second and 2.3 for third repeat keratoplasty. Keratoconus had the longest graft survival (median 13.0 years). In surviving grafts, median visual acuity was 6/15 at 1 year and 6/12 at 2 years. On multivariate analysis, regraft number (P = .022), non-European ethnicity (P = .007), concurrent surgical procedure (P < .0005), lower donor endothelial density (P = .028), previous glaucoma surgery (P < .0005), postoperative raised intraocular pressure (P = .001) and graft rejection (P = .032) were associated with keratoplasty failure. CONCLUSIONS AND RELEVANCE: Repeat keratoplasty survival is affected by multiple interacting factors and prognosis worsens with each subsequent regraft. These results will help guide clinicians in addressing patients' individual risk factors when embarking on repeat corneal transplant surgery.