title: Scanning laser polarimetry in corneal topographic changes after photorefractive keratectomy.
abstract: OBJECTIVE
  To examine whether, or not, corneal topographic changes after excimer laser photorefractive keratectomy (PRK) for myopia and myopic astigmatism have any influence on measurements of the retinal nerve fiber layer (NFL) with scanning laser polarimetry.
  
  
  METHODS
  Retinal NFL thicknesses were determined by scanning laser polarimetry in 17 eyes of 13 patients with myopia and myopic astigmatism before and after PRK. Total ablation depth ranged from 26 to 71 microm. We used the relative ratios for superior and inferior NFL thicknesses which were calculated by dividing the NFL values of respective regions by the nasal value.
  
  
  RESULTS
  The mean superior NFL ratio measured was 3.02 +/- 0.92 preoperatively, and 3.00 +/- 0.76 postoperatively. The mean inferior NFL ratio was 2.95 +/- 0.75 preoperatively, and 2.99 +/- 0.66 postoperatively. There was no statistically significant difference between preoperative and postoperative NFL measurements (Wilcoxon signed rank test, p > 0.05).
  
  
  CONCLUSIONS
  Corneal topographic changes after PRK have no significant influence on NFL measurements by scanning laser polarimetry. Our results suggest that scanning laser polarimetry can be used as a reliable method for retinal NFL thickness measurements even after excimer laser PRK.
authors.affiliation: School of Medicine, Gazi University, Ophthalmology Department, Ankara, Turkey.
authors.forename: S
authors.initials: S
authors.lastname: Ozdek
authors.forename: M
authors.initials: M
authors.lastname: Onol
authors.forename: K
authors.initials: K
authors.lastname: Bilgihan
authors.forename: F
authors.initials: F
authors.lastname: Akata
authors.forename: B
authors.initials: B
authors.lastname: Hasanreisoğlu
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000601:surgery; D019781:Corneal Topography; D003941:Diagnostic Techniques, Ophthalmological; D005500:Follow-Up Studies; D006801:Humans; D007834:Lasers; D054018:Lasers, Excimer; D009216:Myopia / Q000601:surgery; D009412:Nerve Fibers; D009900:Optic Nerve / Q000033:anatomy & histology*; D018903:Photorefractive Keratectomy; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014792:Visual Acuity