scholarly journals Evaluation of the effect of elevated intraocular pressure and reduced ocular perfusion pressure on retinal capillary bed filling and total retinal blood flow in rats by OMAG/OCT

2015 ◽  
Vol 101 ◽  
pp. 86-95 ◽  
Author(s):  
Zhongwei Zhi ◽  
William Cepurna ◽  
Elaine Johnson ◽  
Hari Jayaram ◽  
John Morrison ◽  
...  
Keyword(s):  
Blood Flow ◽  
Intraocular Pressure ◽  
Perfusion Pressure ◽  
Retinal Blood Flow ◽  
Ocular Perfusion Pressure ◽  
Ocular Perfusion ◽  
Retinal Capillary ◽  
Elevated Intraocular Pressure ◽  
Capillary Bed

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.

The Effect of Prone Positioning on Intraocular Pressure in Anesthetized Patients

2001 ◽  
Vol 95 (6) ◽  
pp. 1351-1355 ◽  
Author(s):  
Mary Ann Cheng ◽  
Alexandre Todorov ◽  
René Tempelhoff ◽  
Tom McHugh ◽  
C. Michael Crowder ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Prone Position ◽  
Repeated Measures ◽  
Perfusion Pressure ◽  
Prone Positioning ◽  
Ocular Perfusion Pressure ◽  
Ocular Perfusion ◽  
American Society

Background Ocular perfusion pressure is commonly defined as mean arterial pressure minus intraocular pressure (IOP). Changes in mean arterial pressure or IOP can affect ocular perfusion pressure. IOP has not been studied in this context in the prone anesthetized patient. Methods After institutional human studies committee approval and informed consent, 20 patients (American Society of Anesthesiologists physical status I-III) without eye disease who were scheduled for spine surgery in the prone position were enrolled. IOP was measured with a Tono-pen XL handheld tonometer at five time points: awake supine (baseline), anesthetized (supine 1), anesthetized prone (prone 1), anesthetized prone at conclusion of case (prone 2), and anesthetized supine before wake-up (supine 2). Anesthetic protocol was standardized. The head was positioned with a pinned head-holder. Data were analyzed with repeated-measures analysis of variance and paired t test. Results Supine 1 IOP (13 +/- 1 mmHg) decreased from baseline (19 +/- 1 mmHg) (P < 0.05). Prone 1 IOP (27 +/- 2 mmHg) increased in comparison with baseline (P < 0.05) and supine 1 (P < 0.05). Prone 2 IOP (40 +/- 2 mmHg) was measured after 320 +/- 107 min in the prone position and was significantly increased in comparison with all previous measurements (P < 0.05). Supine 2 IOP (31 +/- 2 mmHg) decreased in comparison with prone 2 IOP (P < 0.05) but was relatively elevated in comparison with supine 1 and baseline (P < 0.05). Hemodynamic and ventilatory parameters remained unchanged during the prone period. Conclusions Prone positioning increases IOP during anesthesia. Ocular perfusion pressure could therefore decrease, despite maintenance of normotension.

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