title: Reproducibility of optical coherence tomography in multiple sclerosis.
abstract: BACKGROUND
  Optical coherence tomography (OCT) is a promising new method of quantifying axon thickness in the retinal nerve fiber layer (RNFL) that has been used predominantly by ophthalmologists to monitor glaucoma. Optical coherence tomography is being considered as a potential outcome measure in multiple sclerosis (MS) clinical trials, but no data exist on the reproducibility of this technique in MS centers.
  
  
  OBJECTIVE
  To determine the reproducibility of OCT measurement of mean RNFL thickness in the undilated eyes of healthy control subjects and patients with MS.
  
  
  METHODS
  Prospective analysis of 4 healthy controls to determine interrater, intrarater, and longitudinal reproducibility. Cross-sectional analysis of 3 cohorts of patients with MS (n = 396) and healthy controls (n = 153).
  
  
  METHODS
  Multiple sclerosis clinics at 3 academic medical centers.
  
  
  METHODS
  Healthy controls and patients with MS. Main Outcome Measure Thickness of RNFL.
  
  
  RESULTS
  We found excellent agreement with respect to interrater (intraclass correlation [ICC], 0.89), intrarater (ICC, 0.98), and intervisit (ICC, 0.91) results. Mean RNFL thickness did not vary significantly among research centers for patients with MS (93, 92, and 90 microm) or among healthy controls (103, 105, and 104 microm) by site.
  
  
  CONCLUSIONS
  We demonstrate that mean RNFL thickness can be reproducibly measured by trained technicians in an MS center using the OCT-3 model. The RNFL measures from cohorts of age-matched controls and patients with MS from 3 different research centers were remarkably similar.
authors.affiliation: Pathology Bldg, Ste 627, The Johns Hopkins Hospital, 600 N Wolfe St, Baltimore, MD 21287, USA.
authors.forename: Deanna
authors.initials: D
authors.lastname: Cettomai
authors.forename: Mathew
authors.initials: M
authors.lastname: Pulicken
authors.forename: Eliza
authors.initials: E
authors.lastname: Gordon-Lipkin
authors.forename: Amber
authors.initials: A
authors.lastname: Salter
authors.forename: Teresa C
authors.initials: TC
authors.lastname: Frohman
authors.forename: Amy
authors.initials: A
authors.lastname: Conger
authors.forename: Xiao
authors.initials: X
authors.lastname: Zhang
authors.forename: Gary
authors.initials: G
authors.lastname: Cutter
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Balcer
authors.forename: Elliot M
authors.initials: EM
authors.lastname: Frohman
authors.forename: Peter A
authors.initials: PA
authors.lastname: Calabresi
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020528:Multiple Sclerosis, Chronic Progressive / Q000175:diagnosis / Q000473:pathology*; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000175:diagnosis / Q000473:pathology*; D011446:Prospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods / Q000592:standards*