Intraocular pressure and retinal blood flow in the normal and glaucomatous eye

1992 ◽  
Vol 55 ◽  
pp. 171
Author(s):  
Juan E. Grunwald
Keyword(s):  
Blood Flow ◽  
Intraocular Pressure ◽  
Retinal Blood Flow

Retinal Vascular Implications of Ocular Hypertension

2021 ◽  
Author(s):  
Fidan Jmor ◽  
John C. Chen
Keyword(s):  
Blood Flow ◽  
Diabetic Retinopathy ◽  
Intraocular Pressure ◽  
Vascular Anatomy ◽  
Flow Regulation ◽  
Retinal Blood Flow ◽  
Vein Occlusion ◽  
Ocular Perfusion ◽  
The Relationship ◽  
Central Retinal Vein

In this chapter, we review the basics of retinal vascular anatomy and discuss the physiologic process of retinal blood flow regulation. We then aim to explore the relationship between intraocular pressure and retinal circulation, taking into account factors that affect retinal hemodynamics. Specifically, we discuss the concepts of ocular perfusion pressure, baro-damage to the endothelium and transmural pressure in relation to the intraocular pressure. Finally, we demonstrate the inter-relationships of these factors and concepts in the pathogenesis of some retinal vascular conditions; more particularly, through examples of two common clinical pathologies of diabetic retinopathy and central retinal vein occlusion.

scholarly journals Intraocular Pressure, Blood Pressure, and Retinal Blood Flow Autoregulation: A Mathematical Model to Clarify Their Relationship and Clinical Relevance

2014 ◽  
Vol 55 (7) ◽  
pp. 4105 ◽  
Author(s):  
Giovanna Guidoboni ◽  
Alon Harris ◽  
Simone Cassani ◽  
Julia Arciero ◽  
Brent Siesky ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Mathematical Model ◽  
Blood Flow ◽  
Intraocular Pressure ◽  
Clinical Relevance ◽  
Retinal Blood Flow

scholarly journals Evaluation of Retinal Blood Flow in Glaucoma Patients Pre and Post Treatment using OCT angiography

2021 ◽  
Vol 4 (1) ◽  
pp. 201-209
Author(s):  
Riad H ◽  
Liu L
Keyword(s):  
Blood Flow ◽  
Intraocular Pressure ◽  
Statistical Significance ◽  
Retinal Blood Flow ◽  
Z Score ◽  
Cross Sectional ◽  
Vascular Plexus ◽  
Microvascular Changes ◽  
Significant Difference ◽  
Insight Into

Purpose: To evaluate retinal blood flow changes in glaucoma after intraocular pressure (IOP) lowering and to determine whether a correlation exists with retinal capillaries blood flow with IOP changes using optical coherence tomography angiography (OCTA) Materials and Methods: OCTA images were collected from 24 glaucomatous eyes for the macula and 21 eyes for the optic disc in a prospective, cross-sectional observational study. Microvascular changes were analysed at two retinal layers: deep vascular plexus (DVP) and the superficial vascular plexus (SVP) as well as choriocapillaries (CC), were compared pre and six weeks post intraocular pressure (IOP) lowering treatment. Results: Retinal blood flow across the macula showed no statistical significance at: SVP (z-score = -0.887), DVP (z-score = -1.093) and CC (z-score = -1.423). Further, no statistically significant difference in retinal blood flow was observed across the disc: SVP (z-score = -0.918), DVP (z-score = -1.057) and CC (z-score = -0.295). While the IOP showed improvement (z-score = -5.049), visual acuity deteriorated (z-score= 1.686) Conclusion: No statistical difference was found in the data for all layers of both the areas surrounding the disc and macula at 6 weeks. OCTA can detect microstructural defects and future longitudinal studies may provide further insight into effects of IOP lowering treatment on retinal blood flow in glaucoma patients in longer term.

scholarly journals Change in retinal blood flow and retinal arterial diameter after intraocular pressure reduction in glaucomatous eyes

2013 ◽  
Vol 92 (6) ◽  
pp. 507-512 ◽  
Author(s):  
Leena Kurvinen ◽  
Janne P. Kytö ◽  
Paula Summanen ◽  
Eija Vesti ◽  
Mika Harju
Keyword(s):  
Blood Flow ◽  
Intraocular Pressure ◽  
Retinal Blood Flow ◽  
Pressure Reduction ◽  
Arterial Diameter ◽  
Intraocular Pressure Reduction

scholarly journals ETa-receptor blockade, but not ACE inhibition, blunts retinal vessel response during isometric exercise

2006 ◽  
Vol 290 (4) ◽  
pp. H1693-H1698 ◽  
Author(s):  
Alexandra Luksch ◽  
Barbara Wimpissinger ◽  
Kaija Polak ◽  
Kerstin Jandrasits ◽  
Leopold Schmetterer
Keyword(s):  
Blood Flow ◽  
Intraocular Pressure ◽  
Angiotensin Ii ◽  
Isometric Exercise ◽  
Retinal Vessel ◽  
Flow Regulation ◽  
Retinal Blood Flow ◽  
Receptor Blockade ◽  
Converting Enzyme ◽  
Retinal Vessel Diameters

Angiotensin II and endothelin-1 are potent vasoconstrictors that appear to play a role in retinal blood flow regulation. In the present study, we investigated the possible role of the angiotensin and the endothelin system in the regulation of retinal vessel diameters during isometric exercise in healthy humans. The study design was randomized, double-masked, placebo-controlled, and three-way cross over. Twelve healthy subjects performed squatting exercises for 6 min during infusion of either an angiotensin-converting enzyme inhibitor (enalapril), an ETA-receptor antagonist (BQ-123), or placebo. Retinal vessel diameters were measured continuously with the Zeiss retinal vessel analyzer. Systemic hemodynamics were assessed noninvasively, and intraocular pressure was measured with applanation tonometry. Squatting induced a significant increase in blood pressure and pulse rate, which was paralleled by a vasoconstriction in retinal arteries and veins. Intraocular pressure was only slightly increased during the squatting periods. BQ-123 significantly blunted the exercise-induced decrease in venous ( P < 0.01) and arterial ( P < 0.02, ANOVA) vessel diameters but had no effect on basal retinal diameters. By contrast, enalapril did neither influence vessel diameter at baseline conditions nor in response to isometric exercise. The data of the present study indicate that retinal vasoconstriction during isometric exercise is modified by ETA-receptor blockade, whereas it is not altered by angiotensin-converting enzyme inhibition. Hence, the present data indicate that endothelin-1, but not angiotensin II, is involved in retinal blood flow regulation during isometric exercise.

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