title: Photorefractive keratectomy for -1.25 to -25.00 diopters of myopia.
abstract: BACKGROUND
  We evaluated prospectively the efficacy, predictability, stability, and safety of photorefractive keratectomy (PRK) for myopia.
  
  
  METHODS
  Three hundred sixty-nine eyes of 257 patients were treated with an Aesculap-Meditec MEL 60 excimer laser. Treated eyes were divided into 3 groups: low myopes (-1.25 to -6.00 D), 226 eyes; medium myopes (-6.10 to -10.00 D), 104 eyes; high myopes (-10.10 to -25.00 D), 39 eyes. Follow-up at 12 months was available for 348 eyes (94%).
  
  
  RESULTS
  One year after surgery the number of eyes within +/- 1.00 D of emmetropia was 182 (86.7%) for low myopes, 43 (40.5%) for medium myopes, and 12 (30.8%) for high myopes. Values for +/- 0.50 D were low: 142 (67.6%), medium: 29 (29.3%), and high: 9 (23.1%). Three eyes with low myopia (1.4%) and 5 eyes with medium myopia (5.1%) lost 2 or more lines of spectacle-corrected visual acuity. None of the high myopes lost 2 or more lines. Uncorrected visual acuity of 20/20 or better was achieved in 82 eyes (39%) with low myopia; 20/40 or better was achieved in 183 eyes (87.1%). Five eyes (5.1%) of medium myopes achieved 20/20 or better; 52 eyes (52.5%) with medium myopia achieved 20/40 or better. Zero eyes with high myopia achieved 20/20 or better; 11 eyes (28.8%) achieved 20/40 or better.
  
  
  CONCLUSIONS
  Photorefractive keratectomy proved to be an effective method to correct myopia up to -6.00 D. For myopia greater than -6.00 D, good results were achieved in most eyes when myopia was less than -10.00 D, but efficacy and predictability decrease. To avoid systematic undercorrection, slight overcorrection must be attempted with the Aesculap-Meditec MEL 60 excimer laser for the treatment of myopia.
authors.affiliation: Department of Ophthalmology, University of Tampere, Medical School, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Pietilä
authors.forename: P
authors.initials: P
authors.lastname: Mäkinen
authors.forename: S
authors.initials: S
authors.lastname: Pajari
authors.forename: H
authors.initials: H
authors.lastname: Uusitalo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003315:Cornea / Q000503:physiopathology / Q000601:surgery*; D005139:Eyeglasses; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007429:Intraocular Pressure; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D018903:Photorefractive Keratectomy; D011183:Postoperative Complications; D011446:Prospective Studies; D012029:Refraction, Ocular; D012449:Safety; D016896:Treatment Outcome; D014792:Visual Acuity