title: Reproducibility of retinal nerve fiber layer thickness measurements using spectral domain optical coherence tomography.
abstract: OBJECTIVE
  To evaluate the reproducibility of the peripapillary retinal nerve fiber layer (RNFL) thickness measurements obtained by Spectralis spectral domain optical coherence tomography (OCT) (Heidelberg Engineering, Heidelberg, Germany) in normal and glaucoma participants.
  
  
  METHODS
  Participants were recruited from a university-based clinic. Peripapillary RNFL thickness measurements were repeated 3 times during the same visit using the follow-up function. One eye of each participant was randomly selected for statistical analysis. Reproducibility was evaluated using within-subject standard deviation (Sw), coefficient of variation (CV), and intraclass correlation coefficient (ICC). Spearman rank correlation coefficient analyses were used to assess the correlation of the standard deviation of the 3 measurements for each participant with the RNFL thickness value.
  
  
  RESULTS
  Forty-five normal participants and 33 glaucoma patients were included in the study. The CVs ranged from 1.45% [overall global (G)] to 2.59% [temporal quadrant (T)] in normal eyes and from 1.74% (G) to 3.22% (T) in the glaucomatous eyes. ICCs ranged from 0.977 (T) to 0.990 (G and inferior-nasal sector) in normal eyes and from 0.983 (T) to 0.997 (inferior quadrant) in glaucomatous eyes. Sw were from 1.34 μm (G) to 2.39 μm (superior-temporal and inferior-temporal sectors) in normal eyes and from 1.14 μm (G) to 2.25 μm (superior-nasal sector) in the glaucomatous eyes. There were no significant correlations between RNFL thickness values and the measurement variability for each participant.
  
  
  CONCLUSIONS
  Spectralis OCT shows excellent reproducibility for measuring the peripapillary RNFL thickness values in both healthy and glaucoma participants.
authors.affiliation: Glaucoma Service, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
authors.forename: Huijuan
authors.initials: H
authors.lastname: Wu
authors.forename: Johannes F
authors.initials: JF
authors.lastname: de Boer
authors.forename: Teresa C
authors.initials: TC
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005901:Glaucoma / Q000175:diagnosis*; D006068:Gonioscopy; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000295:instrumentation*; D014065:Tonometry, Ocular; D055815:Young Adult