title: Repeatability and reproducibility of retinal thickness measurements with spectral-domain optical coherence tomography using different scan parameters.
abstract: OBJECTIVE
  To evaluate repeatability (test-retest) and reproducibility of retinal thickness measurements using spectral-domain optical coherence tomography with different densities of A-scans per B-scan and different frames per B-scan for real-time averaging.
  
  
  METHODS
  Twelve healthy subjects were analyzed by spectral-domain optical coherence tomography. Raster lines analysis with 19 B-scans over the examined area centered on the macula was performed. Images were acquired both in standard-density (768 A-scans/B-scan) and high-density (1,536 A-scans/B-scan) modalities. Moreover, images were acquired using 2 and 20 frames/B-scan for real-time averaging. Each analysis was repeated twice to test for repeatability.
  
  
  RESULTS
  Intersession repeatability was good for all studied analysis protocols, with Lin concordance correlation coefficient values ranging between 0.88 and 1.00. Reproducibility assessment showed consistent retinal thickness measurements using variable scan density, with Bland-Altman limits of agreement of -6 μm to 6 μm in the central area. Reproducibility assessment showed consistent retinal thickness measurements using different number of frames used in the real-time averaging process, with Bland-Altman limits of agreement of -8 μm to 4 μm in the central area.
  
  
  CONCLUSIONS
  Spectral-domain optical coherence tomography is a very reliable tool for central retinal thickness assessment. Changes in the number of A-scans/B-scan and in frames used for real-time averaging do not affect repeatability and reproducibility.
authors.affiliation: Eye Clinic, Department of Clinical Science Luigi Sacco, Sacco Hospital, University of Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Giani
authors.forename: Antonio Peroglio
authors.initials: AP
authors.lastname: Deiro
authors.forename: Giovanni
authors.initials: G
authors.lastname: Staurenghi
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011446:Prospective Studies; D012016:Reference Values; D015203:Reproducibility of Results; D012160:Retina / Q000033:anatomy & histology*; D041623:Tomography, Optical Coherence / Q000295:instrumentation*