title: Avoiding serious corneal complications of laser assisted in situ keratomileusis and photorefractive keratectomy.
abstract: OBJECTIVE
  To identify avoidable factors that can lead to serious complications of laser refractive surgery (photorefractive keratectomy [PRK] and laser assisted in situ keratomileusis [LASIK]).
  
  
  METHODS
  Noncomparative case series.
  
  
  METHODS
  Twenty-seven eyes of 19 patients who had undergone either LASIK or PRK with severe complications accrued retrospectively.
  
  
  METHODS
  Review of clinical records.
  
  
  METHODS
  Symptoms, refractive outcome, and assessment of avoidable factors contributing to the complication.
  
  
  RESULTS
  Patients were analyzed in four groups: group 1, scarring with ectasia; group 2, unrecognized keratoconus; group 3, flap related LASIK complications; and group 4, multiple retreatments. The 8 eyes with scarring and ectasia presented with the worst vision, 20/400 uncorrected visual acuity and 20/200 best spectacle-corrected visual acuity, with avoidable factors considered as high or difficult prescriptions with multiple retreatments. Four eyes in two patients with possible forme fruste keratoconus showed worsening irregular astigmatism. Laser assisted in situ keratomileusis flap complications included six eyes with partial laser treatment under an incomplete flap with subsequent severe irregular astigmatism. Six eyes in three patients who had undergone an average of three multiple retreatments showed decreased vision with irregular astigmatism.
  
  
  CONCLUSIONS
  Certain severe complications of laser refractive surgery likely can be avoided by using caution when treating high prescriptions, particularly with retreatments, recognizing early keratoconus and avoiding laser treatment under a partial flap in LASIK.
authors.affiliation: Department of Ophthalmology, University of British Columbia, Vancouver, Canada.
authors.forename: S P
authors.initials: SP
authors.lastname: Holland
authors.forename: S
authors.initials: S
authors.lastname: Srivannaboon
authors.forename: D Z
authors.initials: DZ
authors.lastname: Reinstein
mesh_terms: D000328:Adult; D003316:Corneal Diseases / Q000209:etiology / Q000517:prevention & control*; D019781:Corneal Topography; D004108:Dilatation, Pathologic / Q000209:etiology / Q000517:prevention & control; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000209:etiology / Q000517:prevention & control; D020731:Keratomileusis, Laser In Situ / Q000009:adverse effects*; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D018903:Photorefractive Keratectomy / Q000009:adverse effects*; D011183:Postoperative Complications / Q000517:prevention & control*; D012086:Reoperation; D012189:Retrospective Studies; D013524:Surgical Flaps; D014792:Visual Acuity