title: Repeatability of retinal thickness measurements between spectral-domain and time-domain optical coherence tomography images in macular disease.
abstract: OBJECTIVE
  To evaluate and compare the intra-session repeatability of retinal thickness measurements from the Topcon 3D OCT 1000 (Topcon Medical Systems; Paramus, NJ), a spectral-domain optical coherence tomography (SD-OCT) system, with the Stratus (Carl Zeiss Meditec, Inc., Dublin, CA), a time-domain OCT (TD-OCT) system, in eyes with retinal diseases.
  
  
  METHODS
  Repeated scans with both SD-OCT and TD-OCT were taken. Thickness measurements from high-quality scans were used to assess repeatability and compare measurements between the two instruments.
  
  
  RESULTS
  Paired scans from 127 eyes were evaluated, of which 63 pairs were of high quality. Coefficients of repeatability and variation for the central subfield were 20.1 μm (2.6%) with SD-OCT and 27.4 μm (4%) with TD-OCT (P = .38). The mean difference in central subfield thickness between the two instruments was 24.5 μm (standard deviation = 20.9).
  
  
  CONCLUSIONS
  Repeatability of retinal thickness measurements with the Topcon 3D OCT 1000 is comparable to the Stratus. The measurements of the two machines differ significantly and cannot be used interchangeably.
authors.affiliation: Fundus Photograph Reading Center, Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
authors.forename: Amitha
authors.initials: A
authors.lastname: Domalpally
authors.forename: Sapna
authors.initials: S
authors.lastname: Gangaputra
authors.forename: Qian
authors.initials: Q
authors.lastname: Peng
authors.forename: Ronald P
authors.initials: RP
authors.lastname: Danis
mesh_terms: D000886:Anthropometry; D001837:Body Weights and Measures; D003930:Diabetic Retinopathy / Q000175:diagnosis*; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D006801:Humans; D008268:Macular Degeneration / Q000175:diagnosis*; D008269:Macular Edema / Q000175:diagnosis*; D015203:Reproducibility of Results; D012160:Retina / Q000473:pathology*; D012170:Retinal Vein Occlusion / Q000175:diagnosis*; D041623:Tomography, Optical Coherence / Q000295:instrumentation*