Search results for "Ciliary Arteries"

2016

AbstractShort posterior ciliary arteries (sPCA) provide the major blood supply to the optic nerve head. Emerging evidence has linked structural and functional anomalies of sPCA to the pathogenesis of several ocular disorders that cause varying degrees of visual loss, particularly anterior ischaemic optic neuropathy and glaucoma. Although the functional relevance of this vascular bed is well-recognized, the proteome of sPCA remains uncharacterized. Since the porcine ocular system closely resembles that of the human’s and is increasingly employed in translational ophthalmic research, this study characterized the proteome of porcine sPCA employing the mass spectrometry-based proteomics strateg…

Main posterior watershed zone of the choroid

1989

The main posterior watershed zone of the choroid is located between the nasal edge of the optic disc and the fovea and represents the area situated between the territories supplied by the temporal and nasal posterior ciliary arteries. In the fluorescein angiographies of 800 normal subjects a watershed zone was not observed in 33.1% due to technical reasons and in 22.3% due to the simultaneous filling of the peripapillar and macular choriocapillaris. In the remaining 44.6% the watershed zone was well outlined: it was straddling the optic disc in about half of these cases and involved the temporal half of the optic disc and the close choroid in the other half. Very rarely the watershed zone i…

Uveal effusion syndrome complicated by anterior ischemic optic neuropathy

1995

We report on a case of idiopathic uveal effusion syndrome complicated by AION. To our knowledge such an association hasn't been previously described. We suggest that scleral thickening caused obstruction of vortex veins followed by uveal effusion and compression of posterior ciliary arteries within their intrascleral tract, leading to AION. Nevertheless it can't be excluded that AION was the result of mechanical compression on ciliary vessels of optic disc by choroidal detachment. © 1996, Kluwer Academic Publishers. All rights reserved.

Responses of retinal arterioles and ciliary arteries in pigs with acute respiratory distress syndrome (ARDS)

2019

Abstract Acute respiratory distress syndrome (ARDS) is a clinical syndrome of acute lung failure in critically sick patients, which severely compromises the function of multiple organs, including the brain. Although, the optic nerve and the retina are a part of the central nervous system, the effects of ARDS on these ocular structures are completely unknown. Thus, the major goal of this study was to test the hypothesis that ARDS affects vascular function in the eye. ARDS was induced in anesthetized pigs by intratracheal injection of lipopolysaccharide (LPS). Sham-treated animals served as controls. Pigs were monitored for 8 h and then sacrificed. Subsequently, retinal arterioles and short p…

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…

Optic Nerve Decompression Improves Hemodynamic Parameters in Papilledema

1993

Purpose: The purpose of this study is to examine changes in color Doppler imaging parameters before and after optic nerve sheath decompression (ONSD) for chronic papilledema caused by pseudotumor cerebri (PTC). Methods: Color Doppler imaging was performed within 48 hours before surgery and within 48 hours after the procedure using a color Doppler unit with a 7.5-MHz phased linear transducer. Pulsed Doppler spectrum analyses were recorded digitally on videotape from the ophthalmic, central retinal, and short posterior ciliary arteries, using a 0.4 × 0.6-mm sample volume. Results: Blood flow velocities in the ophthalmic, short posterior ciliary, and central retinal arteries of 24 eyes were si…

Color Doppler Imaging of Arterial Blood Flow in Central Retinal Vein Occlusion

1994

Purpose: The hemodynamics of the retrobulbar arterial circulation of patients with central retinal vein occlusion were evaluated in order to better understand the pathophysiology of this disease. Methods: Color Doppler imaging was used to measure the peak systolic velocity and vascular resistance (pulsatility index) in the retrobulbar arteries of involved eyes and clinically healthy fellow eyes of patients with central retinal vein occlusion and in the control eyes of age- and sex-matched healthy volunteers. Results: Average peak systolic velocity was significantly lower and average vascular resistance was significantly higher in the central retinal artery of involved eyes of patients with …

Color Doppler Imaging of the Ocular Ischemic Syndrome

1992

Purpose: This study describes hemodynamic characteristics of the ophthalmic, central retinal, and posterior ciliary arteries in 16 eyes of 11 patients with the ocular ischemic syndrome. Understanding the hemodynamic characteristics of the retrobulbar circulation may elucidate the natural history and pathophysiology of the ocular ischemic syndrome and perhaps form the basis for rational treatment of this condition. Methods: Color Doppler imaging, a procedure that permits rapid noninvasive imaging of the ophthalmic, central retinal, and posterior ciliary arteries, was used to quantitate peak systolic blood flow velocities and vascular resistance (pulsatility index) within these vessels in stu…

Color Doppler imaging of the eye and orbit A synopsis of a 400 case experience

2009

Color Doppler imaging (CDI) is a recent advance in ultrasonography that allows simultaneous two-dimensional imaging of structure and blood flow. Doppler information is superimposed in color over a conventional gray-scale ultrasound image. Using this technique we have examined 400 eyes. The central retinal artery, posterior ciliary arteries, ophthalmic artery, the central retinal vein and the vortex veins could be located in all normal eyes. Using the color image as a guide, Doppler spectral analysis is used for quantitative assessment of blood flow velocity in these vessels. We also studied patients with intraocular tumors, arterial and venous retinal occlusions, orbital vascular anomalies …