title: Color Doppler imaging of ophthalmic artery blood flow velocity: a study of repeatability and agreement.
abstract: OBJECTIVE
  Color Doppler imaging (CDI) is a relatively new technique that allows quantification of blood flow velocity in orbital and ocular vasculature. Despite the numerous clinical studies that have used CDI, repeatability of this technique and agreement between observers have not been documented.
  
  
  METHODS
  The authors performed a prospective investigation of the repeatability and agreement between observers on ophthalmic artery blood flow velocity measurements in 35 patients (35 eyes).
  
  
  RESULTS
  Results on the estimated error of measurement (variability between repeated readings on the same subject) indicate good repeatability of the measurements; in fact, the measurement variances were only 5.6% for the peak systolic velocity, 11.4% for the end diastolic velocity, and 6.2% for the mean envelope velocity. The statistical analysis of repeatability showed a very narrow 95% confidence interval for both observers. The measurement of agreement between the two observers demonstrated the existence of a good concordance of the measurements taken by each observer on each subject.
  
  
  CONCLUSIONS
  Results suggest that CDI is a reliable tool for quantitative assessment of ophthalmic artery blood flow velocity.
authors.affiliation: Centro Glaucoma-Clinica Oculistica, Università degli Studi di Brescia,Italy.
authors.forename: L
authors.initials: L
authors.lastname: Quaranta
authors.forename: A
authors.initials: A
authors.lastname: Harris
authors.forename: F
authors.initials: F
authors.lastname: Donato
authors.forename: M
authors.initials: M
authors.lastname: Cassamali
authors.forename: F
authors.initials: F
authors.lastname: Semeraro
authors.forename: G
authors.initials: G
authors.lastname: Nascimbeni
authors.forename: E
authors.initials: E
authors.lastname: Gandolfo
authors.forename: C A
authors.initials: CA
authors.lastname: Quaranta
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001783:Blood Flow Velocity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D009880:Ophthalmic Artery / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D018615:Ultrasonography, Doppler, Color