title: Anterior corneal surface after Nidek EC-5000 multipass and multizone photorefractive keratectomy for myopia.
abstract: OBJECTIVE
  To evaluate the correlation between the presence of irregularities in corneal ablation and the number of ablation zones with multipass and multizone photorefractive keratectomy (PRK).
  
  
  METHODS
  The differential maps obtained from corneal topography performed before and 1 month after PRK in 62 eyes that had undergone PRK with the Nidek EC-5000 excimer laser were assessed for irregularities. PRK treatment ranged from -1.00 to -16.00 D (mean -5.25 +/- 2.72 D), and the number of zones ranged from one to five.
  
  
  RESULTS
  Of 62 differential maps, 27 had an irregular pattern according to the Hersh classification, with a non-significant correlation with the number of treatment zones (chi2 = 5.09, P >.1).
  
  
  CONCLUSIONS
  Our results suggest that corneal topography irregularities arising from multizone PRK were not related to the amount of treatment or to the number of ablation zones.
authors.affiliation: Eye Department, 2nd University of Naples, Italy. nicrosa@tin.it
authors.forename: Nicola
authors.initials: N
authors.lastname: Rosa
authors.forename: Michele
authors.initials: M
authors.lastname: Lanza
authors.forename: Giuseppe
authors.initials: G
authors.lastname: De Rosa
authors.forename: Antonio
authors.initials: A
authors.lastname: Romano
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000601:surgery; D003315:Cornea / Q000473:pathology* / Q000601:surgery; D019781:Corneal Topography; D006801:Humans; D054018:Lasers, Excimer; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D018903:Photorefractive Keratectomy / Q000295:instrumentation / Q000379:methods*; D012029:Refraction, Ocular; D014792:Visual Acuity