| Noninvasive measurements and analysis of blood velocity profiles in human retinal vessels. | |
| | |
MedLine Citation:
|
PMID: 21467177 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
PURPOSE: To quantitatively model the changes in blood velocity profiles for different cardiac phases in human retinal vessels. METHODS: An adaptive optics scanning laser ophthalmoscope (AOSLO) was used to measure blood velocity profiles in three healthy subjects. Blood velocity was measured by tracking erythrocytes moving across a scanning line. From the radial position of the cells within the lumen, the blood velocity profile was computed. The cardiac pulsatility was recorded with a cardiac signal monitor. RESULTS: The shape of the blood velocity profile in retinal arteries changed systematically during the cardiac cycle, with the flattest profile occurring during the diastolic phase. The measured blood velocity profiles were typically flatter than the commonly assumed parabolic shape. The flatness increased with decreasing vessel size. For the large veins (>80 μm), the ratio of the centerline velocity to the cross-sectional average velocity was between 1.50 and 1.65. This ratio decreased to 1.36 in the smallest vein studied (32 μm). Velocity profiles downstream from a venous confluence showed two peaks at 120 μm from the confluence, but a single velocity peak 500 μm downstream from the confluence. CONCLUSIONS: The cardiac cycle influences the blood flow velocity profiles systematically in retinal arteries but not in veins. Parabolic flow was not found in even the largest vessels studied, and deviations from parabolic flow increased in smaller vessels. The measurements are sensitive enough to measure the dual-humped blood velocity profile at a vein confluence. |
| | |
Authors:
|
Zhangyi Zhong; Hongxin Song; Toco Yuen Ping Chui; Benno L Petrig; Stephen A Burns |
Related Documents
:
|
17114977 - Microcirculation during cardiac arrest and resuscitation. 20179137 - Improved drainage with active chest tube clearance. 8969027 - Blood flow in the internal mammary artery after the administration of papaverine during... 8294157 - Alterations in erythrocyte morphology induced by blood pumps. 369007 - Methylprednisolone in the prevention of cerebral hemodynamic and metabolic disorders du... 10846777 - Blood flow velocity waveforms of the fetal pulmonary artery and the ductus arteriosus: ... |
Publication Detail:
|
Type: Journal Article; Research Support, N.I.H., Extramural Date: 2011-06-13 |
Journal Detail:
|
Title: Investigative ophthalmology & visual science Volume: 52 ISSN: 1552-5783 ISO Abbreviation: Invest. Ophthalmol. Vis. Sci. Publication Date: 2011 Jun |
Date Detail:
|
Created Date: 2011-06-14 Completed Date: 2011-08-23 Revised Date: 2012-05-15 |
Medline Journal Info:
|
Nlm Unique ID: 7703701 Medline TA: Invest Ophthalmol Vis Sci Country: United States |
Other Details:
|
Languages: eng Pagination: 4151-7 Citation Subset: IM |
Affiliation:
|
School of Optometry, Indiana University, Bloomington, Indiana 47405-3635, USA. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adult Blood Flow Velocity* Diastole Erythrocytes / physiology Humans Microscopy, Confocal Models, Cardiovascular Ophthalmoscopy Retinal Artery / physiology* Retinal Vein / physiology* |
| Grant Support | |
ID/Acronym/Agency:
|
EY04395/EY/NEI NIH HHS; EY14375/EY/NEI NIH HHS; P30 EY001319-38/EY/NEI NIH HHS; P30 EY019008/EY/NEI NIH HHS; P30 EY019008-02/EY/NEI NIH HHS; P30EY019008/EY/NEI NIH HHS; R01 EY004395-30/EY/NEI NIH HHS; R01 EY014375-09/EY/NEI NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: TAM receptor knockout mice are susceptible to retinal autoimmune induction.
Next Document: A method to measure and predict rates of regional visual field decay in glaucoma.