Microcirculation of the Ocular Fundus

Cardiovascular Physiology > Microcirculation > Microcirculatory Specialization in Individual Organs

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Charles E Riva, Leopold Schmetterer

10.1002/cphy.cp020416

Source: Supplement 9: Handbook of Physiology, The Cardiovascular System, Microcirculation

Originally published: 2008

Published online: January 2011

Full Article on Wiley Online Library

Abstract
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References

Abstract

The sections in this article are:

1 The Vascular Systems of the Eye Fundus

1.1 Retinal vascular system

1.2 Choroidal vascular system

1.3 The optic nerve head

2 Human Ocular Hemodynamics

2.1 Blood velocity in the ophthalmic artery, central retinal artery, and posterior ciliary arteries

2.2 Blood velocity in the retinal vessels

2.3 Velocity profile of red blood cells in retinal arteries

2.4 Blood velocity in the retinal capillaries

2.5 Blood flow rate

2.6 Uveal and optic nerve blood flow rates

2.7 Effect of aging on ocular blood flow

3 Physiology of Blood Flow Regulation

3.1 Systemic determinants

3.2 Neural determinants

3.3 Local determinants

3.4 Endothelial control

3.5 Neural, endocrine, and paracrine control

4 Ocular Blood Flow and its Regulation in Diseases

4.1 Diabetes

4.2 Ischemia‐reperfusion

4.3 Ocular blood flow in glaucoma

4.4 Ocular blood flow in age‐related macular degeneration

5 Abbreviations

	Figure 1. Blood supply to the eye fundus. ON: optic nerve; OA: ophthalmic artery; CRA: central retinal artery; CA: ciliary arteries (posterior and anterior). (See page 20 in colour section at the back of the book)
	Figure 2. Vasculature of the eye fundus. A: retinal arteries; V: retinal veins; ONH: optic neeve head. The net of choroidal vessels (Ch) is visible behind the retina, particularly in the inferior region of the fundus. *: region of the macula. (See page 20 in colour section at the back of the book)
	Figure 3. Diagram of the retinal vasculature around the fovea in the rhesus monkey derived from more than 80 microscope fields. A and V: arteries and veins, respectively. Reprinted from 7 by permission of the Society for Neuroscience. (See page 20 in colour section at the back of the book)
	Figure 4. Diagram of blood supply of the head and intraorbital part of the optic nerve. C: choroid, R: retina, CRA: central retinal artery. PCA: posterior ciliary arteries, OD: optic disc, S: sclera, SNFL: superficial nerve fiber layer, PR: prelaminar region, LC: lamina cribrosa, CZ: circle of Zinn. Reproduced with permission from Hayreh SS 17
	Figure 5. Velocity profile of red blood cells vs scanning distance d across a human retinal vein (D_i = 152 μm) at three different distances downstream from a junction: (A) about 1 diameter, (B) about 2 diameters, and (C) about 5 diameters. In (C) the profile is already symmetric although still significantly blunted. Error bars are 95% CI of the mean values. Reprinted from 71 by permission of Laser Physics
	Figure 6. Percentage change in diameter of retinal arteries in retinal quadrants in response to systemic hyperoxia. Reprinted from Jean‐Louis et al. 147 by permission of the Association of Research in Vision and Ophthalmology
	Figure 7. Effect of increased ocular perfusion pressure (OPP) induced by isometric exercise on percentage changes in retinal and subfoveal choroidal blood flow (bottom) and vascular resistance (top). Adapted from Robinson et al. 178. Riva et al. 179, Kiss et al. 180 by permission of the Association of Research in Vision and Ophthalmology, and Academic Press, Inc
	Figure 8. Group average ONH blood flow responses of 15 normal volunteers to a diffuse, green flicker stimulation at 15 Hz. Field of stimulation: 25° at posterior pole; modulation depth was 100%. Modified from Riva et al. 261 by permission of Elsevier.
	Figure 9. Percentage change (mean ± SD, n = 12) in choroidal and optic nerve blood flows after administration of L‐NMMA (batched bars: 3 mg/kg over 5 min followed by 30μg/kg per min over 55 min; solid bars: 6 mg/kg over 5 min followed by 60μg/kg per min over 55 min). Hollow bars: placebo. (): significant effect of L‐NMMA versus baseline. Adapted Luksch et al.* 296 by permission of the Association of Research in Vision and Ophthalmology
	Figure 10. Percentage change in optic nerve and choroidal blood flows during infusion of adenosine. (): significant effect of adenosine on blood flow. Adapted from Polska et al.* 366 by permission of the Association of Research in Vision and Ophthalmology
	Figure 11. Mean percentage changes of ocular perfusion pressure (PPm), subfoveal choroidal blood flow (ChBF), and choroidal vascular resistance (Rm) at the end of squatting, for young healthy volunteers (Group I), elderly healthy volunteers with mild macular pigment changes (Group II), and patients with subfoveal classic neovascularization (Group III). In the Group III, ChBF increased significantly. Changes in ChBF and Rm were found to be significantly different between Group II and III (ChBF: * stands for p < 0.0001: Rm: ‡ stands for p = 0.002). Adapted from Pournaras et al. 485 by permission of the Association of Research in Vision and Ophthalmology

Figure 1.

Blood supply to the eye fundus. ON: optic nerve; OA: ophthalmic artery; CRA: central retinal artery; CA: ciliary arteries (posterior and anterior). (See page 20 in colour section at the back of the book)

Figure 2.

Vasculature of the eye fundus. A: retinal arteries; V: retinal veins; ONH: optic neeve head. The net of choroidal vessels (Ch) is visible behind the retina, particularly in the inferior region of the fundus. *: region of the macula. (See page 20 in colour section at the back of the book)

Figure 3.

Diagram of the retinal vasculature around the fovea in the rhesus monkey derived from more than 80 microscope fields. A and V: arteries and veins, respectively.

Reprinted from 7 by permission of the Society for Neuroscience. (See page 20 in colour section at the back of the book)

Figure 4.

Diagram of blood supply of the head and intraorbital part of the optic nerve. C: choroid, R: retina, CRA: central retinal artery. PCA: posterior ciliary arteries, OD: optic disc, S: sclera, SNFL: superficial nerve fiber layer, PR: prelaminar region, LC: lamina cribrosa, CZ: circle of Zinn.

Reproduced with permission from Hayreh SS 17

Figure 5.

Velocity profile of red blood cells vs scanning distance d across a human retinal vein (D_i = 152 μm) at three different distances downstream from a junction: (A) about 1 diameter, (B) about 2 diameters, and (C) about 5 diameters. In (C) the profile is already symmetric although still significantly blunted. Error bars are 95% CI of the mean values.

Reprinted from 71 by permission of Laser Physics

Figure 6.

Percentage change in diameter of retinal arteries in retinal quadrants in response to systemic hyperoxia.

Reprinted from Jean‐Louis et al. 147 by permission of the Association of Research in Vision and Ophthalmology

Figure 7.

Effect of increased ocular perfusion pressure (OPP) induced by isometric exercise on percentage changes in retinal and subfoveal choroidal blood flow (bottom) and vascular resistance (top).

Adapted from Robinson et al. 178. Riva et al. 179, Kiss et al. 180 by permission of the Association of Research in Vision and Ophthalmology, and Academic Press, Inc

Figure 8.

Group average ONH blood flow responses of 15 normal volunteers to a diffuse, green flicker stimulation at 15 Hz. Field of stimulation: 25° at posterior pole; modulation depth was 100%. Modified from Riva et al. 261 by permission of Elsevier.

Figure 9.

Percentage change (mean ± SD, n = 12) in choroidal and optic nerve blood flows after administration of L‐NMMA (batched bars: 3 mg/kg over 5 min followed by 30μg/kg per min over 55 min; solid bars: 6 mg/kg over 5 min followed by 60μg/kg per min over 55 min). Hollow bars: placebo. (*): significant effect of L‐NMMA versus baseline.

Adapted Luksch et al. 296 by permission of the Association of Research in Vision and Ophthalmology

Figure 10.

Percentage change in optic nerve and choroidal blood flows during infusion of adenosine. (*): significant effect of adenosine on blood flow.

Adapted from Polska et al. 366 by permission of the Association of Research in Vision and Ophthalmology

Figure 11.

Mean percentage changes of ocular perfusion pressure (PPm), subfoveal choroidal blood flow (ChBF), and choroidal vascular resistance (Rm) at the end of squatting, for young healthy volunteers (Group I), elderly healthy volunteers with mild macular pigment changes (Group II), and patients with subfoveal classic neovascularization (Group III). In the Group III, ChBF increased significantly. Changes in ChBF and Rm were found to be significantly different between Group II and III (ChBF: * stands for p < 0.0001: Rm: ‡ stands for p = 0.002).

Adapted from Pournaras et al. 485 by permission of the Association of Research in Vision and Ophthalmology

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Article Title:	Microcirculation of the Ocular Fundus
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Charles E Riva, Leopold Schmetterer. Microcirculation of the Ocular Fundus. Compr Physiol 2011, Supplement 9: Handbook of Physiology, The Cardiovascular System, Microcirculation: 735-765. First published in print 2008. doi: 10.1002/cphy.cp020416

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