title: Endothelial keratoplasty after failed penetrating keratoplasty: an alternative to repeat penetrating keratoplasty.
abstract: OBJECTIVE
  To analyze graft survival of endothelial keratoplasty (EK) under a previous failed penetrating keratoplasty (PK) compared to repeat PK.
  
  
  METHODS
  Retrospective, comparative case series.
  
  
  METHODS
  Analysis involved consecutive patients who underwent either a repeat PK or EK under PK, after failed PK, whose primary surgical indication was pseudophakic bullous keratopathy at a single tertiary center. Clinical data and donor and recipient characteristics were recorded from our prospective cohort from the Singapore Corneal Transplant Study. Main outcome measure was graft survival up to 5 years follow-up.
  
  
  RESULTS
  We included a total of 113 eyes that underwent a repeat PK (n = 81) or EK under a failed PK (n = 32). Cumulative graft survival probabilities comparing repeat PK with EK under PK were at 91.9% vs 96.2% (1 year), 82.6% vs 91.6% (2 years), 66.8% vs 86.4% (3 years), and 51.3% vs 86.4% up to 5 years follow-up, respectively (log-rank P value = .013). Multivariate Cox regression analysis was performed, which adjusted for: age, sex, risk factors for graft failure (corneal neovascularization, ocular surface disease, glaucoma, active corneal inflammation, anterior synechiae), donor endothelial cell count, and repeat donor size. Repeat PK was a significant risk factor for graft failure compared to performing an EK under PK (hazard ratio: 10.17; 95% CI 1.10-93.63; P = .041).
  
  
  CONCLUSIONS
  In our study of eyes with bullous keratopathy, endothelial keratoplasty under a previously failed PK provided better graft survival outcomes than repeat PK, adjusting for potential confounders and risk factors for graft failure.
authors.affiliation: Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, Singapore.
authors.forename: Marcus
authors.initials: M
authors.lastname: Ang
authors.affiliation: Singapore National Eye Centre, Singapore.
authors.forename: Henrietta
authors.initials: H
authors.lastname: Ho
authors.affiliation: Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, Singapore.
authors.forename: Cheewai
authors.initials: C
authors.lastname: Wong
authors.affiliation: Singapore Eye Research Institute, Singapore.
authors.forename: Hla Myint
authors.initials: HM
authors.lastname: Htoon
authors.affiliation: Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, Singapore; Department of Clinical Sciences, Duke-National University of Singapore Graduate Medical School, Singapore.
authors.forename: Jodhbir S
authors.initials: JS
authors.lastname: Mehta
authors.affiliation: Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, Singapore; Department of Ophthalmology, National University Health System, Singapore; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore. Electronic address: donald.tan.t.h@snec.com.sg.
authors.forename: Donald
authors.initials: D
authors.lastname: Tan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001768:Blister / Q000601:surgery*; D003316:Corneal Diseases / Q000601:surgery*; D004728:Endothelium, Corneal / Q000637:transplantation*; D005260:Female; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000601:surgery*; D006085:Graft Survival / Q000502:physiology; D006801:Humans; D015948:Keratoplasty, Penetrating; D008297:Male; D008875:Middle Aged; D012086:Reoperation; D012189:Retrospective Studies; D014019:Tissue Donors; D017211:Treatment Failure