title: Visual acuity outcomes in eyes with flat corneas after PRK.
abstract: OBJECTIVE
  To evaluate the impact of corneal curvatures less than 35 diopters (D) after photorefractive keratectomy (PRK) on visual acuity outcomes.
  
  
  METHODS
  Visual acuity outcomes of 5,410 eyes that underwent PRK from January 2006 to November 2010 were retrospectively analyzed for the impact of postoperative corneal curvatures on visual outcomes. All procedures were performed on a single platform (Allegretto 200Hz excimer laser; Alcon Laboratories, Inc., Irvine, CA). Main outcome measures were postoperative corrected distance visual acuity (CDVA) and loss of CDVA.
  
  
  RESULTS
  Corneas with a measured or a calculated postoperative flat meridian less than 35 D and those with a measured postoperative steep meridian less than 35 D had worse postoperative CDVA than corneas with meridians of either 35 D or more (P ≤ .021). However, the preoperative CDVA was worse in the flatter curvatures in all comparisons performed (P ≤ .024). Consequently, the measured or calculated meridian curvature had no effect on CDVA loss (P ≥ .074).
  
  
  CONCLUSIONS
  Postoperative corneal keratometry values (flat and steep meridians) less than 35 D did not have a predictive effect on the risk of losing visual acuity following myopic PRK performed on the Allegretto 200Hz excimer laser.
authors.affiliation: Department of Ophthalmology, Tel-Aviv Medical Center, Tel-Aviv University, Tel-Aviv, Israel. varssano@gmail.com
authors.forename: David
authors.initials: D
authors.lastname: Varssano
authors.forename: Michael
authors.initials: M
authors.lastname: Waisbourd
authors.forename: Liza
authors.initials: L
authors.lastname: Minkev
authors.forename: Tzahi
authors.initials: T
authors.lastname: Sela
authors.forename: Meira
authors.initials: M
authors.lastname: Neudorfer
authors.forename: Perry S
authors.initials: PS
authors.lastname: Binder
mesh_terms: D000293:Adolescent; D000328:Adult; D003315:Cornea / Q000473:pathology* / Q000601:surgery; D019781:Corneal Topography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D018903:Photorefractive Keratectomy; D011184:Postoperative Period; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity; D055815:Young Adult