Search results for "Retinal Artery"

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…

Central retinal artery occlusion-A new, provisional treatment approach.

2019

The retinal ganglion cells infarcted in central retinal artery occlusion (CRAO) are the somata of the optic nerve axons, part of the central nervous system. Consequently, CRAO with inner retinal infarction is a small vessel stroke, usually with the devastating consequence of severe visual loss in the affected eye. At present, there is no generally accepted, evidence-based therapy of nonarteritic CRAO in contrast to ischemic cerebral stroke that has well-accepted treatment protocols. Widely divergent and controversial therapeutic options for CRAO reflect the desperation of treating physicians and disparate conflicting studies. We examine reasons why treatment of nonarteritic CRAO remains pro…

Incidence of retinal artery occlusion in Germany

2020

Correlation Between Ischemic Retinal Accidents and Radial Peripapillary Capillaries in the Optic Nerve Using Optical Coherence Tomographic Angiograph…

2017

Background: Perfusion of the optic nerve has been widely studied using fluorescein angiography (FAG), which is currently regarded as the criterion standard. However, FAG has adverse effects associated with intravenous contrast administration and is limited in its capacity to characterize and stratify the different vascular layers of the optic nerve and retina. The use of new imaging techniques, such as optical coherence tomographic angiography (Angio-OCT), is therefore important. Aim: A qualitative description is made of the vascular layers of the optic nerve and of how vascular events affect radial peripapillary capillaries (RPC). Two patients with central retinal artery occlusion (CRAO), …

Microaneurysm detection with radon transform-based classification on retina images.

2012

The creation of an automatic diabetic retinopathy screening system using retina cameras is currently receiving considerable interest in the medical imaging community. The detection of microaneurysms is a key element in this effort. In this work, we propose a new microaneurysms segmentation technique based on a novel application of the radon transform, which is able to identify these lesions without any previous knowledge of the retina morphological features and with minimal image preprocessing. The algorithm has been evaluated on the Retinopathy Online Challenge public dataset, and its performance compares with the best current techniques. The performance is particularly good at low false p…

Short-Time Ocular Ischemia Induces Vascular Endothelial Dysfunction and Ganglion Cell Loss in the Pig Retina

2019

Visual impairment and blindness are often caused by retinal ischemia-reperfusion (I/R) injury. We aimed to characterize a new model of I/R in pigs, in which the intraocular pathways were not manipulated by invasive methods on the ocular system. After 12 min of ischemia followed by 20 h of reperfusion, reactivity of retinal arterioles was measured in vitro by video microscopy. Dihydroethidium (DHE) staining, qPCR, immunohistochemistry, quantification of neurons in the retinal ganglion cell layer, and histological examination was performed. Retinal arterioles of I/R-treated pigs displayed marked attenuation in response to the endothelium-dependent vasodilator, bradykinin, compared to sham-tre…

2017

Background Patients with retinal vascular occlusion disease have an increased risk for ischemic stroke and share some risk factors with cerebrovascular disease. The purpose of this study was to analyze the prevalence of atrial fibrillation (AF) in subjects with retinal vascular occlusive disease and anterior ischemic optic neuropathy and to compare these data to an ischemic stroke group. Methods Prospective, observational single-center trial. Subjects with retinal artery occlusion (RAO), retinal vein occlusion (RVO) and anterior ischemic optic neuropathy (AION) were included. Patients with ischemic stroke (IS) from a previous observational trial were used as control. Investigation included …

Systemische fibrinolytische Therapie mit Urokinase bei Zentralarterienverschluss der Netzhaut

2005

BACKGROUND AND OBJECTIVE Systemic fibrinolysis has become an important therapeutical option in patients with thrombotic occlusion of coronary or pulmonary arteries. In view of the hemorrhagic risk systemic fibrinolytic therapy for retinal vessel occlusion has been discussed controversial. In the present case study results and complications of systemic fibrinolysis should be investigated in patients with central retinal artery occlusion. PATIENTS AND METHODS From 1995 to 2002 a case series of 19 consecutive patients (8 female, 11 male, age: 63.2+/-14,3 years) with central retinal artery occlusion were treated by systemic application of urokinase using a standardized scheme. The latency from …

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 …