title: Photorefractive keratectomy for astigmatism greater than -2.00 diopters in eyes with low, high, or extreme myopia.
abstract: OBJECTIVE
  To assess the efficacy of excimer laser photorefractive astigmatic keratectomy (PARK) in correcting astigmatism of more than -2.00 diopters (D) in eyes with low, high, and extreme myopia.
  
  
  METHODS
  Pusan National University Hospital, Pusan, Korea.
  
  
  METHODS
  Eighty-five patients (110 eyes) whose spherical error ranged from -3.00 to -13.00 D and cylinder ranged from -2.00 to -5.50 D had PARK with a VISX Twenty-Twenty excimer laser; follow-up was 6 months. All cases of myopic astigmatism were treated using the elliptical method and multizone ablation technique. Eyes were divided into 3 groups: low myopia, less than 6.00 D (n = 47); high myopia, from 6.25 to 10.00 D (n = 43); extreme myopia, over 10.25 D (n = 20). Alpins vector analysis was used to calculate the astigmatic change.
  
  
  RESULTS
  By vector analysis, the success rate of astigmatic correction was more predictable in the low and high myopia groups than in the extreme myopia group (P < .05). There was little improvement in astigmatism in the extreme myopia group.
  
  
  CONCLUSIONS
  Using PARK to correct astigmatism greater than -2.00 D in eyes with myopia less than -10.00 D tended to result in undercorrection; astigmatic correction in eyes with myopia over 10.25 D was minimal.
authors.affiliation: Department of Ophthalmology, College of Medicine, Pusan National University, Korea.
authors.forename: J S
authors.initials: JS
authors.lastname: Lee
authors.forename: B S
authors.initials: BS
authors.lastname: Oum
authors.forename: B J
authors.initials: BJ
authors.lastname: Lee
authors.forename: S H
authors.initials: SH
authors.lastname: Lee
mesh_terms: D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage; D001251:Astigmatism / Q000150:complications / Q000188:drug therapy / Q000601:surgery*; D003315:Cornea / Q000187:drug effects / Q000601:surgery*; D004008:Diclofenac / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000150:complications / Q000188:drug therapy / Q000601:surgery*; D018903:Photorefractive Keratectomy; D016896:Treatment Outcome; D014792:Visual Acuity
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D004008:Diclofenac