title: Long-term refractive outcomes and stability after excimer laser surgery for myopia.
abstract: OBJECTIVE
  To evaluate the long-term refractive outcomes of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) for myopia.
  
  
  METHODS
  Centre for Eye Research Australia, Melbourne, Australia.
  
  
  METHODS
  Comparative case series.
  
  
  METHODS
  Preoperative baseline refractions in eyes having PRK, LASIK, or both at 1 multisurgeon center were analyzed from patient databases. Two- to 13-year follow-up data were analyzed and compared with 1-month postoperative visual outcomes.
  
  
  RESULTS
  The study evaluated 389 eyes (229 patients). In the PRK group, the mean preoperative spherical equivalent (SE) was -4.05 diopters (D) ± 1.17 (SD) in eyes with low to moderate myopia and -7.97 ± 2.00 D in eyes with high myopia (P = .009) and in the LASIK group, -3.98 ± 1.27 D and -7.64 ± 1.66 D, respectively (P = .008). At the last visit, the mean SE in the PRK group was -0.64 ± 0.83 D in eyes with low to moderate myopia and -1.06 ± 1.74 D in eyes with high myopia (P = .73) and in the LASIK group, -0.33 ± 0.59 D and -0.63 ± 0.90 D, respectively (P = .68). At the end of the study, 45.9% of eyes with low to moderate myopia and 25.0% with high myopia in the PRK group and 64.8% and 37.3%, respectively, in the LASIK group were within ± 0.50 D of the attempted correction.
  
  
  CONCLUSIONS
  Laser refractive surgery effectively treated all levels of myopia. Refractive stability was achieved within 1 year postoperatively, with LASIK showing better stability than PRK for up to 6 to 9 years.
authors.affiliation: Centre for Eye Research Australia, University of Melbourne, Melbourne, Victoria, Australia. dirani@unimelb.edu.au
authors.forename: Mohamed
authors.initials: M
authors.lastname: Dirani
authors.forename: Terry
authors.initials: T
authors.lastname: Couper
authors.forename: Joanne
authors.initials: J
authors.lastname: Yau
authors.forename: Eng K
authors.initials: EK
authors.lastname: Ang
authors.forename: F M Amirul
authors.initials: FM
authors.lastname: Islam
authors.forename: Grant R
authors.initials: GR
authors.lastname: Snibson
authors.forename: Rasik B
authors.initials: RB
authors.lastname: Vajpayee
authors.forename: Paul N
authors.initials: PN
authors.lastname: Baird
mesh_terms: D000328:Adult; D003315:Cornea / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D018903:Photorefractive Keratectomy; D012029:Refraction, Ocular / Q000502:physiology*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology*