title: [Noninvasive two-dimensional analysis of microcirculation in optic nerve head and choroid--calibration of the normalized blur (NB) value].
abstract: We have developed an apparatus using the laser speckle phenomenon for noninvasive two-dimensional measurements of the fundus microcirculation. The normalized blur of the speckle pattern (NB value) was adopted as an index of blood flow velocity in the tissue. The present study investigated whether the NB value can be also used as a quantitative index of the blood flow rate in the tissue. In experimental animals, an injection of a lethal dose of pentobarbital causes rapid reduction in the ocular perfusion pressure (OPP), which linearly correlates with blood flow rate in the ocular tissue. The NB in rabbit optic nerve head (ONH) tissue showed a linear correlation (r = 0.98, p < 0.001) with the OPP after injection of a lethal dose of pentobarbital, which suggested that the NB value parallels the blood flow rate in the ONH tissue. At various levels of OPP, the choroidal NB showed a good correlation (r = 0.60, p < 0.001) with the choroidal blood flow rate measured with microsphere technique. These results indicated that the NB value can be used as a quantitative index not only for the blood flow velocity but also for the blood flow rate in the tissue.
authors.affiliation: Eye Clinic, Tokyo Metropolitan Geriatric Hospital, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tamaki
authors.forename: E
authors.initials: E
authors.lastname: Kawamoto
authors.forename: M
authors.initials: M
authors.lastname: Araie
authors.forename: S
authors.initials: S
authors.lastname: Eguchi
authors.forename: H
authors.initials: H
authors.lastname: Fujii
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology; D002829:Choroid / Q000098:blood supply*; D007834:Lasers; D008722:Methods; D008833:Microcirculation / Q000033:anatomy & histology; D009898:Optic Disk / Q000098:blood supply*; D011817:Rabbits