title: Inter-method agreement in retinal blood vessels diameter analysis between Dynamic Vessel Analyzer and optical coherence tomography.
abstract: OBJECTIVE
  To analyze the inter-methods agreement in arteriovenous ratio (AVR) evaluation between spectral-domain optical coherence tomography (SD-OCT) and Dynamic Vessel Analyzer (DVA).
  
  
  METHODS
  Healthy volunteers underwent DVA and SD-OCT examination. AVR was measured by SD-OCT using the four external lines of the optic nerve head-centered 7-line cube and by DVA using an automated AVR estimation. The mean AVR was calculated, twice, separately by two independent readers for each tool.
  
  
  RESULTS
  Twenty-two eyes of 11 healthy subjects (five women and six men, mean age 35) were included. AVR analysis by DVA showed high inter-observer agreement between reader 1 and 2, and high intra-observer agreement for both reader 1 and reader 2. With regard to AVR analysis on SD-OCT, we found high inter-observer agreement between reader 1 and 2, and low intra-observer agreement for reader 2 but high intra-observer agreement for reader 1. Overall, the mean AVR measured on SD-OCT turned out to be significantly higher than mean AVR measured through DVA (reader 1, 0.9023 ± 0.06 vs 0.8036 ± 0.08; p < 0.001, and reader 2, 0.9067 ± 0.06 vs 0.8083 ± 0.05; p= 0.003).
  
  
  CONCLUSIONS
  No inter-method agreement in AVR could be detected in the present study due to bias in measurements (shift between DVA and SD-OCT). We found significant difference in the two noninvasive methods for AVR measurement, with a tendency for SD-OCT to overestimate retinal vascular caliber in comparison to DVA. This may be useful for achieving greater accuracy in the evaluation of retinal vessel in ocular as well as systemic diseases.
authors.affiliation: Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, Milan, 20132, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Benatti
authors.affiliation: Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, Milan, 20132, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Corvi
authors.affiliation: Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, Milan, 20132, Italy.
authors.forename: Livia
authors.initials: L
authors.lastname: Tomasso
authors.affiliation: Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, Milan, 20132, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Mercuri
authors.affiliation: Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, Milan, 20132, Italy.
authors.forename: Lea
authors.initials: L
authors.lastname: Querques
authors.affiliation: Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, Milan, 20132, Italy.
authors.forename: Fulvio
authors.initials: F
authors.lastname: Ricceri
authors.affiliation: Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, Milan, 20132, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Bandello
authors.affiliation: Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, Milan, 20132, Italy. giuseppe.querques@hotmail.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Querques
mesh_terms: D000328:Adult; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D015588:Observer Variation; D015203:Reproducibility of Results; D012171:Retinal Vessels / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*; D055815:Young Adult
keywords: Arteriovenous ratio; Dynamic vessel analyzer; Inter-methods agreement; Reproducibility; Semi-automated analysis; Spectral-domain optical coherence tomography