title: Retinal vessel diameter measurements by spectral domain optical coherence tomography.
abstract: OBJECTIVE
  To describe a spectral domain optical coherence (OCT)-assisted method of measuring retinal vessel diameters.
  
  
  METHODS
  All Patients with an OCT circle scan centered at the optic nerve head using a Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) were retrospectively reviewed. Individual retinal vessels were identified on infrared reflectance (IR) images and given unique labels both on IR and spectral domain OCT (SD-OCT). Vessel width and vessel types obtained by IR were documented as ground truth. From OCT, measurements of each vessel, including horizontal vessel contour diameter, vertical vessel contour diameter, horizontal hyperreflective core diameter, and reflectance shadowing width, were assessed.
  
  
  RESULTS
  A total of 220 vessels from 13 eyes of 12 patients were labeled, among which, 194 vessels (88 arteries and 65 veins confirmed from IR) larger than 40 microns were included in the study. The mean vessel width obtained from IR was 107.9 ± 36.1 microns. A mean vertical vessel contour diameter of 119.6 ± 29.9 microns and a mean horizontal vessel contour diameter of 124.1 ± 31.1 microns were measured by SD-OCT. Vertical vessel contour diameter did not differ from vessel width in all subgroup analysis. Horizontal vessel contour diameter was not significantly different from vessel width for arteries and had strong or very strong correlation with vessel width for veins.
  
  
  CONCLUSIONS
  In our study, vertical vessel contour diameter measured by current commercially available SD-OCT was consistent with vessel width obtained by IR with good reproducibility. This SD-OCT based method could potentially be used as a standard measurement procedure to evaluate retinal vessel diameters and their changes in ocular and systemic disorders.
authors.affiliation: Department of Ophthalmology, Charité-University Medicine Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Ouyang
authors.forename: Qing
authors.initials: Q
authors.lastname: Shao
authors.forename: Dirk
authors.initials: D
authors.lastname: Scharf
authors.forename: Antonia M
authors.initials: AM
authors.lastname: Joussen
authors.forename: Florian M
authors.initials: FM
authors.lastname: Heussen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003930:Diabetic Retinopathy / Q000150:complications; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000150:complications; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D009898:Optic Disk / Q000098:blood supply*; D009929:Organ Size; D015203:Reproducibility of Results; D012161:Retinal Artery / Q000473:pathology*; D012169:Retinal Vein / Q000473:pathology*; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*; D014605:Uveitis / Q000150:complications; D055815:Young Adult