Search results for "ophthalmic artery"

Bioenergetic shift and actin cytoskeleton remodelling as acute vascular adaptive mechanisms to angiotensin II in murine retina and ophthalmic artery

2020

Ocular vascular dysfunction is a major contributing factor to the pathogenesis of glaucoma. In recent years, there has been a renewed interest in the role of angiotensin II (Ang II) in mediating the disease progression. Despite its (patho)physiological importance, the molecular mechanisms underlying Ang II-mediated oxidative stress remain largely unexplored in the ocular vasculature. Here, we provide the first direct evidence of the alterations of proteome and signalling pathways underlying Ang II-elicited oxidative insult independent of arterial pressure changes in the ophthalmic artery (OA) and retina (R) employing an in vitro experimental model. Both R and OA were isolated from male C57B…

Resistive index of ophthalmic artery as an imaging biomarker of hypertension-related vascular and kidney damage

2021

Aim: Resistive index of ophthalmic artery (RI-OA) is associated with atherosclerotic diseases. The aim of this study was to evaluate the association of RI-OA and hypertension-related vascular and kidney damage. Materials and methods: Two-hundred and eighty hypertensive patients underwent evaluation of RI-OA, carotid atherosclerosis and level of 24 h albuminuria. Results: Albuminuria and carotid atherosclerosis were positively associated with RI-OA independently of other cardiovascular risk factors. Receiver-operating characteristic curve analysis allowed us to calculate a cut-off value of RI-OA >0.625, which would be suspicious about the existence of atherosclerotic disease. Conclusion:…

Experimental Percutaneous Cannulation of the Supraorbital Arteries: Implication for Future Therapy

2005

Purpose There is some evidence to suggest that thrombolysis has a beneficial effect in retinal vessel occlusion. However, there is concern that this therapeutic approach carries the risk of hemorrhage. Retrograde cannulation of the supraorbital arteries followed by irrigation with fibrinolytic agents may have the potential to minimize the risk of major complications. The study was conducted to investigate the anatomic and sonographic features of the supraorbital arteries. Methods This cadaver dissection study was performed on the orbits of 12 cadaveric specimens. In each orbit, the supraorbital region was dissected, followed by cannulation of the supraorbital vessels and injection of ink. I…

Contralateral and ipsilateral microsurgical approaches to carotid-ophthalmic aneurysms.

1997

Objective The vicinity of carotid-ophthalmic aneurysms to the roof of the cavernous sinus, to the anterior clinoid process, and to the optic nerve or the optic chiasm requires well-defined surgical techniques. Although microsurgical techniques with ipsilateral direct approaches to these aneurysms have been described in detail, studies about contralateral strategies for the microsurgical treatment of carotid-ophthalmic aneurysms are rare and are mainly confined to case reports. The aim of this study is to describe how to decide on the ipsilateral and contralateral microsurgical approaches to such aneurysms and to demonstrate the surgical techniques for the ipsilateral and contralateral expos…

Ophthalmologic Imaging Methods

2005

Color Doppler ultrasonography of the eye and orbit

1993

Color Doppler imaging is the recent development in ultrasonography that allows simultaneous two-dimensional structural imaging in Doppler evaluation of blood flow. With this technique, it is possible for the first time to indirectly display the fine orbital vessels such as the ophthalmic artery and its branches, the central retinal artery, the posterior ciliary artery, and the lacrimal artery. Also, the display of venous structures such as the superior ophthalmic vein, the vortex vein, and the central retinal vein is possible. In addition to the qualitative display of those vessels, the hemodynamics in those vessels can be quantitatively assessed by looking at the Doppler spectrum and deter…

Functional Role of α1-Adrenoceptor Subtypes in Murine Ophthalmic Arteries

2011

PURPOSE To identify the α(1)-adrenoceptor (α(1)-AR) subtypes mediating vascular adrenergic responses in murine ophthalmic arteries. METHODS Expression of mRNA was quantified for individual α(1)-AR subtypes in murine ophthalmic arteries using real-time PCR. To assess the functional relevance of α(1)-ARs for mediating vascular responses, ophthalmic arteries from mice deficient in one of the three α(1)-AR subtypes (α(1A)-AR(-/-), α(1B)-AR(-/-), and α(1D)-AR(-/-), respectively) and wild-type controls were isolated, cannulated with micropipettes, and pressurized. Changes in luminal artery diameter in response to the α(1)-AR agonist phenylephrine, the sympathetic transmitter noradrenaline, and to…

Cholinergic Responses of Ophthalmic Arteries in M3and M5Muscarinic Acetylcholine Receptor Knockout Mice

2009

PURPOSE. To determine the functional role of M 3 and M 5 muscarinic acetylcholine receptor subtypes in ophthalmic arteries using gene-targeted mice. METHODS. Muscarinic receptor gene expression was quantified in murine ophthalmic arteries using real-time PCR. To test the functional relevance of M 3 and M 5 receptors, ophthalmic arteries from mice deficient in either subtype (M3R -/- , M5R -/- , respectively) and wild-type controls were isolated, cannulated with micropipettes, and pressurized. Changes in luminal vessel diameter in response to muscarinic and nonmuscarinic receptor agonists were measured by video microscopy. RESULTS. With the use of real-time PCR, all five muscarinic receptor …

Color Doppler Hemodynamics of Giant Cell Arteritis

1994

Objectives: To determine quantitative and qualitative hemodynamic alterations within the ophthalmic, central retinal, and short posterior ciliary arteries in patients with giant cell arteritis (GCA) proved by biopsy specimen. Design, Patients, and Setting: A consecutive case series of patients with GCA referred to an urban eye hospital who were evaluated with color Doppler imaging that was used to analyze orbital blood flow velocities and vascular resistance in 22 consecutive patients with GCA compared with age and sex-matched controls. Results: Patients with GCA all demonstrated significantly reduced central retinal and short posterior ciliary arterial mean flow velocities as well as signi…

Extracranial internal carotid artery occlusion: the role of common carotid artery volume flow.

2002

BACKGROUND AND PURPOSE Quantitative measurement of blood flow volume in the common carotid artery (CCA) is now possible using the color velocity imaging quantification (CVI-Q) ultrasound technique. The aim of this study was to evaluate the cerebral hemodynamic effects of unilateral internal carotid artery (ICA) occlusion on CCA blood flow volumes (FVs) using CVI-Q. METHODS Records of ultrasound studies in our neurosonology laboratory were retrospectively reviewed to identify patients with unilateral ICA occlusions who at a minimum received both a routine color duplex carotid ultrasound examination and quantitative measurement of FV in the CCA, bilaterally, using the CVI-Q method. A total of…