title: Outcomes of same-sizing versus oversizing donor trephines in keratoconic patients undergoing first penetrating keratoplasty.
abstract: OBJECTIVE
  To investigate whether use of same-size donor and recipient trephines reduced myopia after penetrating keratoplasty for keratoconus.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Eight hundred seventy-eight first grafts for keratoconus were reported to UK Transplant between April 1999 and December 2003. There were 234 and 644 grafts in the same-size and oversize donor trephine groups, respectively. At 1 year, mean spherical equivalent (SE) data were available for 116 eyes (50%) and 295 eyes (46%) in the same-size and oversize groups. At 2 years, mean SE data were available for 64 eyes (27%) and 148 eyes (23%) in the same-size and oversize groups.
  
  
  METHODS
  Logistic regression and univariate analysis of follow-up data submitted to UK Transplant.
  
  
  METHODS
  At 1 and 2 years postoperatively, mean SE, magnitude of the cylindrical component of the refraction, postoperative uncorrected visual acuity (VA), postoperative best-corrected VA, and postoperative complications were recorded.
  
  
  RESULTS
  The mean SEs for the same-size and oversize donor trephine groups, respectively, were -1.45 diopters (D) and -1.41 D at 1 year (P = 0.6) and -1.74 D and -2.19 D at 2 years postoperatively (P = 0.3). Although there were no differences in graft survival between the groups at 1 and 2 years, there was a higher incidence of postoperative wound leaks in the same-size group (P = 0.03).
  
  
  CONCLUSIONS
  Use of same-size donor and recipient trephines did not reduce myopia and was associated with an increased risk of postoperative complications.
authors.affiliation: Bristol Eye Hospital, Bristol, United Kingdom. philipjaycock@hotmail.com
authors.forename: Philip D
authors.initials: PD
authors.lastname: Jaycock
authors.forename: Mark N A
authors.initials: MN
authors.lastname: Jones
authors.forename: John
authors.initials: J
authors.lastname: Males
authors.forename: W John
authors.initials: WJ
authors.lastname: Armitage
authors.forename: Stuart D
authors.initials: SD
authors.lastname: Cook
authors.forename: Derek M
authors.initials: DM
authors.lastname: Tole
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Kaye
mesh_terms: D000328:Adult; D003315:Cornea / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006085:Graft Survival; D006801:Humans; D007640:Keratoconus / Q000601:surgery*; D015948:Keratoplasty, Penetrating / Q000379:methods*; D008297:Male; D009216:Myopia / Q000517:prevention & control; D011183:Postoperative Complications; D012189:Retrospective Studies; D014019:Tissue Donors; D016896:Treatment Outcome; D014792:Visual Acuity