title: Laser in situ keratomileusis for ametropia after penetrating keratoplasty.
abstract: OBJECTIVE
  To evaluate the efficacy of excimer laser in situ keratomileusis (LASIK) in the treatment of refractive errors after penetrating keratoplasty.
  
  
  METHODS
  Eight eyes underwent LASIK after a mean 71 months (SD 60) following the initial penetrating keratoplasty. A full ophthalmic assessment was performed before LASIK and at 1 week, 1, 3, 6, and 12 months after surgery. Mean follow-up was 8.6 months (SD 3.2).
  
  
  RESULTS
  No eyes lost any Snellen lines of best spectacle-corrected visual acuity at the latest follow-up. Mean reduction in spherical equivalent refraction was 91% from -6.79 D (SD 4.17) to -0.64 D (SD 1.92) and mean reduction of cylinder was 72% from -6.79 D (SD 3.28) to -1.93 D (SD 1.17) at 6 months. Mean surgically induced astigmatism was 5.50 D (SD 2.42) and the index of surgically induced astigmatism divided by the initial cylinder expressed as a percentage was 81%. Mean outcome indices were: correction index 0.87, index of success 0.31, and angle of error 0.95 degrees. Three eyes (43%) achieved a spherical equivalent refraction of +/-0.50 D and 4 eyes (57%) achieved a spherical equivalent refraction of +/-1.00 D of emmetropia.
  
  
  CONCLUSIONS
  The efficacy of LASIK after penetrating keratoplasty was good compared to incisional or surface based excimer laser methods and has the advantage of reducing the myopic spherical equivalent refraction in addition to astigmatism, thus improving the uncorrected visual acuities.
authors.affiliation: Corneal Diseases and Excimer Laser Research Unit, University of Dundee, Scotland, United Kingdom. peter@koay.freeserve.co.uk
authors.forename: P Y
authors.initials: PY
authors.lastname: Koay
authors.forename: C N
authors.initials: CN
authors.lastname: McGhee
authors.forename: K H
authors.initials: KH
authors.lastname: Weed
authors.forename: J P
authors.initials: JP
authors.lastname: Craig
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000209:etiology / Q000601:surgery*; D003315:Cornea / Q000473:pathology / Q000601:surgery*; D065306:Corneal Injuries; D005131:Eye Injuries / Q000601:surgery; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000601:surgery; D020731:Keratomileusis, Laser In Situ; D015948:Keratoplasty, Penetrating / Q000009:adverse effects*; D008297:Male; D012029:Refraction, Ocular; D016896:Treatment Outcome; D014792:Visual Acuity