title: Ultrasound measurement of the effect of temperature on microperfusion in the eye.
abstract: Recent developments in ultrasound (US) technology have allowed the study of microperfusion in the anterior segment of the eye. Our aim was to determine the effect of the thermal environment on blood flow in the anterior segment. We measured blood flow in the major arterial circle of five rabbits. A 38-MHz US transducer was coupled to the eye with a normal saline water-bath with temperature controlled from 1 degrees C to 38 degrees C. The major arterial circle was localized and imaged using the swept-scan technique and M-mode data were then acquired for measurement of pulsatile flow. Peak systolic and mean velocity averaged 4.51 and 1.32 mm/s, respectively. Positive correlations were found between peak systolic (1.69%/ degrees C) and mean (1.76%/ degrees C) velocities and temperature. Vessel diameter (mean = 178 microm) did not show any significant change with temperature. High-resolution US flowmetry demonstrated decreasing flow rates in the iris with decreasing temperature.
authors.affiliation: Weill Medical College of Cornell University, New York, NY 10021, USA. prof@boodle.med.cornell.edu
authors.forename: Ronald H
authors.initials: RH
authors.lastname: Silverman
authors.forename: Roxana
authors.initials: R
authors.lastname: Ursea
authors.forename: Dustin
authors.initials: D
authors.lastname: Kruse
authors.forename: Katherine W
authors.initials: KW
authors.lastname: Ferrara
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Rondeau
authors.forename: D Jackson
authors.initials: DJ
authors.lastname: Coleman
mesh_terms: D000818:Animals; D000869:Anterior Eye Segment / Q000098:blood supply / Q000000981:diagnostic imaging; D001783:Blood Flow Velocity; D005123:Eye / Q000098:blood supply* / Q000000981:diagnostic imaging*; D007498:Iris / Q000098:blood supply / Q000000981:diagnostic imaging; D016014:Linear Models; D008833:Microcirculation; D011673:Pulsatile Flow; D011817:Rabbits; D013696:Temperature; D018615:Ultrasonography, Doppler, Color / Q000379:methods