The laser Doppler technique is a clinically applicable, noninvasive technique that enables one to obtain measurements of the blood flow rate at selectable sites in the retinal vasculature. It is the only known noninvasive technique that can provide objective, quantitative measurements of retinal blood flow. In addition, it is the only known technique that can measure instantaneous changes in the velocity of red blood cells flowing in individual retinal vessels, a requirement for the complete characterization of retinal hemodynamics. Because of the large energy requirements of the retina as it functions in the visual process, it requires a well-functioning vascular system to provide a sufficient, well-regulated blood supply. The ability of the retinal circulation to autoregulate its blood supply in accordance with its metabolic needs is central to its proper functioning. Several major disease processes with specific retinal complications have been linked to a pathologic functioning of the autoregulatory mechanism. Further improvements in the laser Doppler technique, its application to studies aimed at elucidating the operation of the autoregulatory mechanism, and its application to studies of retinal vascular disease, with emphasis on diagnosis, prognosis, and monitoring the effectiveness of therapeutic interventions, should lead to substantial new information about retinal blood flow and its role in the development of retinal diseases. Accordingly, the specific aims of the proposed research are: (1) to improve the quality of the data as well as the ease of data acquisition by implementing techniques resulting in stabilization of the incident laser beam on the target vessel, (2) to implement a computer-assisted automatic data analysis system featuring the display of results within minutes of data acquisition, (3) to characterize quantitatively the normal human retinal circulation in terms of blood flow, flow pulsatility, and oxygen delivery, (4) to investigate the autoregulatory response of the retinal circulating to local and systemic perturbations, and (5) to characterize quantitatively the retinal circulation of selected patients with diabetic retinopathy, central and branch vein occlusions, myopia, retinal detachment, and carotid artery disease, and to determine the effects of therapeutic interventions in specific cases.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
2R01EY001303-10
Application #
3255849
Study Section
Visual Sciences A Study Section (VISA)
Project Start
1978-01-01
Project End
1987-12-31
Budget Start
1985-03-01
Budget End
1985-12-31
Support Year
10
Fiscal Year
1985
Total Cost
Indirect Cost
Name
Schepens Eye Research Institute
Department
Type
DUNS #
City
Boston
State
MA
Country
United States
Zip Code
Yoshida, A; Feke, G T; Ogasawara, H et al. (1996) Retinal hemodynamics in middle-aged normal subjects. Ophthalmic Res 28:343-50
Konno, S; Feke, G T; Yoshida, A et al. (1996) Retinal blood flow changes in type I diabetes. A long-term follow-up study. Invest Ophthalmol Vis Sci 37:1140-8
Fujio, N; Feke, G T; Ogasawara, H et al. (1994) Quantitative circulatory measurements in branch retinal vessel occlusion. Eye (Lond) 8 ( Pt 3):324-8
Feke, G T; Buzney, S M; Ogasawara, H et al. (1994) Retinal circulatory abnormalities in type 1 diabetes. Invest Ophthalmol Vis Sci 35:2968-75
Fujio, N; Feke, G T; Goger, D G et al. (1994) Regional retinal blood flow reduction following half fundus photocoagulation treatment. Br J Ophthalmol 78:335-8
Ogasawara, H; Feke, G T; Yoshida, A et al. (1992) Retinal blood flow alterations associated with scleral buckling and encircling procedures. Br J Ophthalmol 76:275-9
Rizzo 3rd, J F; Feke, G T; Goger, D G et al. (1991) Optic nerve head blood speed as a function of age in normal human subjects. Invest Ophthalmol Vis Sci 32:3263-72
Yoshida, A; Feke, G T; Ogasawara, H et al. (1991) Effect of timolol on human retinal, choroidal and optic nerve head circulation. Ophthalmic Res 23:162-70
Milbocker, M T; Feke, G T; Goger, D G (1991) Laser Doppler velocimetry stabilized in one dimension. IEEE Trans Biomed Eng 38:928-30
Feke, G T; Tagawa, H; Deupree, D M et al. (1989) Blood flow in the normal human retina. Invest Ophthalmol Vis Sci 30:58-65

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