The long term objective is the investigation of the physiology of the retinal circulation and of the role played by this circulation in the development of diabetic retinopathy. We will investigate: A. Normal physiology a) The regulation of retinal blood flow (RBF) in response to light/dark transition; b) The regulation of RBF in response to changes in arterial blood oxygen concentration; c) The regulation of RBF in response to changes in perfusion pressure; d) The physiologic principles of optimality underlying retinal arterial branching, radii and flows. B. Diabetic retinopathy a) The prognostic significance and natural history of changes in RBF and blood flow regulation to 100% O2 breathing; b) The correlation between RBF and its regulation to 100% O2, breathing and the electroretinographic oscillatory potentials; c) The correlation between RFB and its regulation to 100% O2, breathing and the clinical response to panretinal laser photocoagulation; d) The effect of an acute drop of blood sugar due to insulin treatment on RBF and its regulation to 100% O2 breathing. These goals will be achieved through the use of Laser Doppler Velocimetry (LDV) and Monochromatic Fundus Photography combined, for the first time, with simultaneous measurements of preretinal PO2. It is hoped that these studies, which blend the efforts of basic scientists and clinicians, will provide a better understanding of the physiology of the retinal circulation and of the microvascular pathophysiology in diabetic retinopathy through a better understanding of the mechanisms underlying retinal vascular responses. This understanding together with the development of new ways of testing RBF regulation may improve the monitoring of the progression of the disease and of the effect of treatment.
| Riva, C E; Cranstoun, S D; Petrig, B L (1996) Effect of decreased ocular perfusion pressure on blood flow and the flicker-induced flow response in the cat optic nerve head. Microvasc Res 52:258-69 |
| Grunwald, J E; DuPont, J; Riva, C E (1996) Retinal haemodynamics in patients with early diabetes mellitus. Br J Ophthalmol 80:327-31 |
| Mann, R M; Riva, C E; Stone, R A et al. (1995) Nitric oxide and choroidal blood flow regulation. Invest Ophthalmol Vis Sci 36:925-30 |
| Vo Van Toi; Riva, C E (1995) Variations of blood flow at optic nerve head induced by sinusoidal flicker stimulation in cats. J Physiol 482 ( Pt 1):189-202 |
| Portellos, M; Riva, C E; Cranstoun, S D et al. (1995) Effects of adenosine on ocular blood flow. Invest Ophthalmol Vis Sci 36:1904-9 |
| Riva, C E; Cranstoun, S D; Grunwald, J E et al. (1994) Choroidal blood flow in the foveal region of the human ocular fundus. Invest Ophthalmol Vis Sci 35:4273-81 |
| Riva, C E; Cranstoun, S D; Mann, R M et al. (1994) Local choroidal blood flow in the cat by laser Doppler flowmetry. Invest Ophthalmol Vis Sci 35:608-18 |
| Scheiner, A J; Riva, C E; Kazahaya, K et al. (1994) Effect of flicker on macular blood flow assessed by the blue field simulation technique. Invest Ophthalmol Vis Sci 35:3436-41 |
| Grunwald, J E; Brucker, A J; Grunwald, S E et al. (1993) Retinal hemodynamics in proliferative diabetic retinopathy. A laser Doppler velocimetry study. Invest Ophthalmol Vis Sci 34:66-71 |
| Pakola, S J; Grunwald, J E (1993) Effects of oxygen and carbon dioxide on human retinal circulation. Invest Ophthalmol Vis Sci 34:2866-70 |
Showing the most recent 10 out of 29 publications
