title: The effect of software upgrade on optical coherence tomography measurement of the retinal nerve fiber layer thickness.
abstract: OBJECTIVE
  To determine the effect of software upgrades on retinal nerve fiber layer (RNFL) thickness measurements taken by spectral domain optical coherence tomography (SD-OCT).
  
  
  METHODS
  Eighty normal eyes (40 patients) were scanned for RNFL thickness measurements using Spectralis (Heidelberg Engineering, Heidelberg, Germany) SD-OCT. Scan analysis was performed using version 4.0 software and then reanalyzed with version 5.1.3. Student paired t testing and Pearson's correlation coefficient were used for statistical analysis.
  
  
  RESULTS
  Average and quadrant RNFL thicknesses generated using version 4.0 and 5.1.3 software on Spectralis demonstrated high correlation (r = 0.955-0.998). Average RNFL thickness using version 4.0 was 0.08 μm thinner than version 5.1.3 (p = 0.409). Quadrant RNFL differences ranged from -0.26 to +0.97 μm (p = 0.146-0.915). Segmentation errors were reduced 33% after the upgrade.
  
  
  CONCLUSIONS
  Minor RNFL thickness changes may occur after software upgrades in Spectralis OCT. The differences did not reach statistical significance but segmentation errors were improved.
authors.affiliation: Department of Ophthalmology, Rocky Mountain Lions Eye Institute, University of Colorado at Denver, Aurora, CO, USA.
authors.forename: Leonard K
authors.initials: LK
authors.lastname: Seibold
authors.forename: Malik Y
authors.initials: MY
authors.lastname: Kahook
mesh_terms: D000328:Adult; D005260:Female; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012984:Software / Q000639:trends*; D041623:Tomography, Optical Coherence / Q000379:methods*; D055815:Young Adult