The aims of this project are: I. Improve the blue field entoptic simulation technique and study the effect of contrast, sharpness, and distribution of simulated leukocytes on the determination of entoptically seen leukocyte speed and number. II. In normal subjects, investigate macular blood flow and its regulation in response to alterations in perfusion pressure and inspired O2 and CO2 concentrations. III. In diabetes, determine (a) whether macular blood flow and its regulation is abnormal in maculopathy, (b) the effect of panretinal photocoagulation on macular blood flow and its regulation and whether the occurrence of macular edema is associated with abnormalities of flow and regulation, (c) whether the blue field entoptic test can be used as a predictor of post-treatment visual acuity in patients undergoing focal photocoagulation for diabetic macular edema, and (d) whether abnormal autoregulation can be correlated with the progression of retinopathy to preproliferative and proliferative stages. IV. In open angle glaucoma, determine (a) the relationship between macular blood flow and perfusion pressure, (b) the effect of topically applied timolol and epinephrine on macular blood flow. V. Develop a simulation of the entoptic observation of the perifoveal microvasculature and investigate, in normal subjects, the size of the foveal avascular zone and the density of the parafoveal capillary network. It is hoped that these studies will help to understand the physiology of the macular retinal microcirculation and to quantify the changes in retinal blood flow and its regulation in diabetes mellitus and open angle glaucoma.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY003388-06
Application #
3257725
Study Section
Visual Sciences A Study Section (VISA)
Project Start
1983-07-01
Project End
1986-06-30
Budget Start
1985-07-01
Budget End
1986-06-30
Support Year
6
Fiscal Year
1985
Total Cost
Indirect Cost
Name
Presbyterian Medical Center of Phila
Department
Type
DUNS #
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Robinson, F; Chen, S; Petrig, B L et al. (1992) The acute effect of topical epinephrine on macular blood flow in humans. Invest Ophthalmol Vis Sci 33:18-22
Sinclair, S H (1991) Macular retinal capillary hemodynamics in diabetic patients. Ophthalmology 98:1580-6
Sinclair, S H; Azar-Cavanagh, M; Soper, K A et al. (1989) Investigation of the source of the blue field entoptic phenomenon. Invest Ophthalmol Vis Sci 30:668-73
Robinson, F; Petrig, B L; Sinclair, S H et al. (1985) Does topical phenylephrine, tropicamide, or proparacaine affect macular blood flow? Ophthalmology 92:1130-2
Robinson, F; Petrig, B L; Riva, C E (1985) The acute effect of cigarette smoking on macular capillary blood flow in humans. Invest Ophthalmol Vis Sci 26:609-13