title: Surgical results of photorefractive keratectomy with different operative modes.
abstract: OBJECTIVE
  To compare the predictability, efficacy, and safety of photorefractive keratectomy (PRK) using different operative modes.
  
  
  METHODS
  National Taiwan University Hospital, Taipei, Taiwan.
  
  
  METHODS
  One hundred fifty-three eyes of 80 patients who had PRK for myopia with a follow-up of at least 6 months were studied. All patients were sequentially assigned to 1 of the following surgical modes: mode 1: PRK with the Summit OmniMed excimer laser; mode 2: PRK with the Summit Apex Plus laser; mode 3: PRK with the Summit Apex Plus laser with anti-central-island pretreatment.
  
  
  RESULTS
  Six months after treatment, a homogeneous topographic pattern was seen in 76% of mode 1 eyes, 70% of mode 2 eyes, and 88% of mode 3 eyes. In the low myopia group (< or =-6.0 diopters [D]), the mean residual refractive error was -0.79 D +/- 0.59 (SD) in mode 1, -0.94 +/- 1.02 D in mode 2, and -0.31 +/- 0.42 D in mode 3. In the high myopia group (>-6.0 D), it was -1.93 +/- 1.51 D, -1.54 +/- 0.88 D, and -0.70 +/- 0.81 D, respectively. Uncorrected visual acuity of 20/25 or better was achieved in 81% of mode 1 eyes, 56% of mode 2 eyes, and 89% of mode 3 eyes in the low myopia group, and in 48%, 28%, and 72%, respectively, in the high myopia group.
  
  
  CONCLUSIONS
  Photorefractive keratectomy appears to be a predictable and effective procedure. The best results were achieved with the Summit Apex Plus laser with anti-central-island pretreatment, followed by the Summit OmniMed laser. The Summit Apex Plus laser without anti-central-island pretreatment produced less satisfactory results.
authors.affiliation: Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: W L
authors.initials: WL
authors.lastname: Chen
authors.forename: F R
authors.initials: FR
authors.lastname: Hu
authors.forename: I J
authors.initials: IJ
authors.lastname: Wang
authors.forename: H W
authors.initials: HW
authors.lastname: Chang
mesh_terms: D000328:Adult; D003315:Cornea / Q000033:anatomy & histology* / Q000601:surgery; D003316:Corneal Diseases / Q000517:prevention & control; D019781:Corneal Topography; D006801:Humans; D054018:Lasers, Excimer; D009216:Myopia / Q000601:surgery*; D018903:Photorefractive Keratectomy / Q000379:methods*; D012029:Refraction, Ocular; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity