title: One year follow-up of photoastigmatic keratectomy (PARK) with the VISX 20/20 excimer laser.
abstract: OBJECTIVE
  One hundred thirteen eyes were treated with photoastigmatic keratectomy using the VISX 20/20 excimer laser. The results were evaluated after 1 year.
  
  
  METHODS
  The patients were divided into 2 groups, low astigmatism group with less than 2.00 diopters (D) of pre-operative astigmatism, the second group having 2.00 D or more.
  
  
  RESULTS
  Astigmatism was reduced by 43.9% in the low astigmatic group and by 71.7% in the high astigmatic group. Eighty percent of the eyes in the low astigmatic group and 90% in the high astigmatic group achieved an uncorrected visual acuity of 20/40 (0.5) or better. Eighty-four percent in the low astigmatic group and 80% in the high astigmatic group were within +/- 1.00 D in spherical equivalent results. The mean spherical equivalent results were about -0.45 D in both groups using this algorithm.
  
  
  CONCLUSIONS
  The results are very promising at this early stage of algorithm development.
authors.affiliation: S:t Erik's Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Hamberg-Nyström
authors.forename: P P
authors.initials: PP
authors.lastname: Fagerholm
authors.forename: B M
authors.initials: BM
authors.lastname: Tengroth
authors.forename: A V
authors.initials: AV
authors.lastname: Viding
mesh_terms: D000328:Adult; D000465:Algorithms; D001251:Astigmatism / Q000473:pathology / Q000601:surgery*; D003315:Cornea / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054018:Lasers, Excimer; D008297:Male; D009216:Myopia / Q000601:surgery*; D018903:Photorefractive Keratectomy / Q000295:instrumentation / Q000379:methods*; D012029:Refraction, Ocular; D014792:Visual Acuity