title: Arterial stiffness shown by the cardio-ankle vascular index is an important contributor to optic nerve head microcirculation.
abstract: METHODS
  The purpose of this study was to determine whether there were significant correlations between the pulse waveform in the capillary area of the optic nerve head (ONH) microcirculation shown by laser speckle flowgraphy (LSFG) and parameters of the systemic condition, especially the cardio-ankle vascular index (CAVI).
  
  
  METHODS
  We studied 130 men (ages 60.5 ± 10.9 years) who visited the Vascular Function Section of the Department of Cardiovascular Center of Toho University Sakura Medical Center. We evaluated the skew and blowout time (BOT) - which are parameters of pulse waveform analyses - using LSFG in the capillary area of the ONH for each patient. The CAVI, the E/e' ratio as the measure of diastolic left ventricular function, and the mean intima-media thickness (IMT) were evaluated as systemic parameters. We performed a Pearson's correlation analysis and a multiple regression analysis to determine independent factors for skew and BOT.
  
  
  RESULTS
  Heart rate, spherical refraction, and the CAVI (standard regression = 0.18, t = 2.61, p = 0.01) were revealed as factors contributing independently to the skew by multiple regression analysis. Heart rate, the CAVI (standard regression = -0.27, t = -3.92, p = 0.0002), the urinary albumin concentration, the mean IMT, spherical refraction, body mass index and pulse pressure were revealed as factors contributing independently to the BOT by multiple regression analysis.
  
  
  CONCLUSIONS
  The CAVI was demonstrated to be an independent factor contributing to both skew and BOT in the capillary area of the ONH. Our findings clarified that large arterial function shown by the CAVI contributes to smooth hemodynamics of microcirculation, shown by LSFG.
authors.affiliation: Department of Ophthalmology, School of Medicine Toho University, Tokyo, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Shiba
authors.affiliation: Cardiovascular Center, Toho University Sakura Medical Center, 564-1 Shimoshizu, Sakura, Chiba, 285-8741, Japan. takahashi-04@sakura.med.toho-u.ac.jp.
authors.forename: Mao
authors.identifier: http://orcid.org/0000-0003-2808-2020
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Department of Ophthalmology, School of Medicine Toho University, Tokyo, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Matsumoto
authors.affiliation: Internal Medicine, Toho University Sakura Medical Center, Sakura, Chiba, Japan.
authors.forename: Kohji
authors.initials: K
authors.lastname: Shirai
authors.affiliation: Department of Ophthalmology, School of Medicine Toho University, Tokyo, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hori
mesh_terms: D055109:Ankle Brachial Index / Q000379:methods*; D001158:Arteries / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology*; D059168:Carotid Intima-Media Thickness; D005500:Follow-Up Studies; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D009898:Optic Disk / Q000098:blood supply*; D012189:Retrospective Studies; D059289:Vascular Stiffness
keywords: Arteriosclerosis; Cardio-ankle vascular index; Laser speckle flowgraphy; Ocular circulation; Pulse waveform analysis