title: Effect of laser in situ keratomileusis on retinal nerve fiber layer thickness measurements by scanning laser polarimetry.
abstract: OBJECTIVE
  To determine the effect of laser in situ keratomileusis (LASIK) on retinal nerve fiber layer measurements by scanning laser polarimetry in a large clinical trial.
  
  
  METHODS
  Asan Medical Center, University of Ulsan, Department of Ophthalmology, Seoul, Korea.
  
  
  METHODS
  Scanning laser polarimetry measurements were performed in 59 eyes of 59 consecutive patients who had LASIK. The mean retardation values of the whole measurement ellipse and of the superior, inferior, temporal, and nasal sectors of the ellipse before and after LASIK were compared statistically.
  
  
  RESULTS
  The mean spherical equivalent refractive error was -6.10 diopters (D) +/- 2.34 (SD) (range -1.19 to -15.50 D) preoperatively and -0.31 +/- 0.52 D (range +0.68 to -2.13 D) postoperatively. The mean ablation depth was 94.0 +/- 30.49 microm (range 28.0 to 161.1 microm). The mean postoperative retardation values of all the sectors and of the superior, temporal, inferior, and nasal sectors showed reduced nerve fiber layer thickness (P =.000, P =.000, P =.011, P =.000, and P=.002, respectively).
  
  
  CONCLUSIONS
  Laser in situ keratomileusis affected nerve fiber layer thickness measurements by scanning laser polarimetry. The change in nerve fiber layer thickness was probably due to modification of the corneal architecture. This effect of keratorefractive surgery should be considered when using scanning laser polarimetry as a diagnostic and follow-up tool for glaucoma.
authors.affiliation: Department of Ophthalmology, Ulsan University College of Medicine, Asan Medical Center, Seoul, South Korea. mskook@amc.seoul.kr
authors.forename: Michael S
authors.initials: MS
authors.lastname: Kook
authors.forename: Sang- un
authors.initials: S
authors.lastname: Lee
authors.forename: Hung- won
authors.initials: H
authors.lastname: Tchah
authors.forename: Kyung- rim
authors.initials: K
authors.lastname: Sung
authors.forename: Ryu- hwa
authors.initials: R
authors.lastname: Park
authors.forename: Kyung- rhee
authors.initials: K
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000886:Anthropometry; D003315:Cornea / Q000601:surgery*; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D007834:Lasers; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D009412:Nerve Fibers; D009900:Optic Nerve / Q000033:anatomy & histology*; D011446:Prospective Studies; D012165:Retinal Ganglion Cells / Q000166:cytology; D058609:Visual Field Tests / Q000379:methods