title: Reproducibility of retinal thickness measurements in normal eyes using optical coherence tomography.
abstract: OBJECTIVE
  To determine the reproducibility of retinal thickness measurements in normal eyes using optical coherence tomography (OCT).
  
  
  METHODS
  Multiple 3.20-mm vertical cross-sectional images through the center of fixation of consecutive patients with normal results on ocular examinations were obtained. Each image was divided into seven 320-micron segments. Regional retinal thicknesses for each section were measured using both the manually assisted (requiring observer localization of reflectivity peaks) and the automated modes (observer-independent measurement) of the computer software.
  
  
  RESULTS
  Eighteen right eyes were studied. The mean coefficient of variation was less than 10% for all locations using the manually assisted method (average standard deviation less than 17 microns [range 9 to 16 microns]). The automated method was less reliable, with a coefficient of variation greater than 10% for locations within 500 microns of fixation. Automated measurements at fixation were the least reproducible because of poor internal limiting membrane reflectivity.
  
  
  CONCLUSIONS
  OCT is capable of reproducible measurement of retinal thickness in normal eyes. Computer-driven, automated measurement of retinal thickness within 500 microns of fixation needs to be refined and its reproducibility reassessed in this region.
authors.affiliation: Department of Ophthalmology, New York Eye and Ear Infirmary, New York 10003, USA.
authors.forename: M
authors.initials: M
authors.lastname: Baumann
authors.forename: R C
authors.initials: RC
authors.lastname: Gentile
authors.forename: J M
authors.initials: JM
authors.lastname: Liebmann
authors.forename: R
authors.initials: R
authors.lastname: Ritch
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D015588:Observer Variation; D012016:Reference Values; D015203:Reproducibility of Results; D012160:Retina / Q000033:anatomy & histology*; D014054:Tomography / Q000379:methods*