{"id":39,"date":"2016-01-27T14:50:45","date_gmt":"2016-01-27T12:50:45","guid":{"rendered":"http:\/\/www.hekimoglugoruntuleme.com\/?p=39"},"modified":"2025-12-05T10:32:09","modified_gmt":"2025-12-05T07:32:09","slug":"orbital-color-doppler-ultrasonography-rdus","status":"publish","type":"post","link":"https:\/\/www.hekimoglugoruntuleme.com\/en\/orbital-color-doppler-ultrasonography-rdus\/","title":{"rendered":"Orbital Color Doppler Ultrasonography (RDUS)"},"content":{"rendered":"

What is Orbital Color Doppler Ultrasound?<\/span><\/h2>\n

Orbital color Doppler ultrasound is an imaging method used to evaluate blood flow in the orbit. It assists in the diagnosis, prognosis, and monitoring of various ophthalmic diseases.
\nColor Doppler ultrasound is a non-invasive technique used to create two-dimensional images of normal and pathological blood vessels. It is an effective tool for investigating and understanding the pathogenesis of various ophthalmic diseases.<\/p>\n

Anatomy and Physiology for Orbital Doppler Ultrasound<\/span><\/h2>\n

The arteries and veins of the orbit show significant variability among individuals. The orbit is primarily supplied by the internal carotid artery circulation, with a small contribution from the external carotid artery circulation.
\nThe main artery of the orbit is the ophthalmic artery. It is the first intracranial branch of the ICA after it exits the cavernous sinus. The ophthalmic artery enters the orbit through the optic canal, located inferolateral to the optic nerve. It passes under the optic nerve, giving rise to the central retinal artery, and then moves superomedial to the optic nerve. The medial and lateral long ciliary arteries supply the outer layers of the globe.<\/p>\n

The venous system of the orbit consists of two major veins: the superior ophthalmic vein (SOV) and the inferior ophthalmic vein (IOV), along with highly variable vessels. The SOV passes through the superior orbital fissure and drains into the cavernous sinus. The IOV can either join the SOV or drain directly into the cavernous sinus.<\/p>\n

Is Preparation Required for Orbital Doppler Ultrasound?<\/span><\/h2>\n

Patients should avoid smoking or alcohol consumption for at least 12 hours before the procedure. The use of topical medications, especially anti-glaucoma drugs, affects orbital blood flow. Factors like hypertension, anxiety, tachycardia, increased cardiac output, and elevated pulse pressure alter retrobulbar hemodynamics. The person performing the examination should minimize the impact of these factors on the study.<\/p>\n

How is Orbital Doppler Ultrasound Performed?<\/span><\/h2>\n

The patient is asked to lie down with their head elevated at a 30-degree angle, with their eyelids gently closed, and look straight ahead. The Doppler ultrasound probe is placed horizontally over the eyelid to obtain an axial image of the orbit. The probe should apply minimal pressure on the globe to avoid compressing the orbital vessels.
\nOphthalmic Artery Imaging: The ophthalmic artery is visualized in the nasal portion of the orbit, where it crosses the optic nerve at a depth of 35 to 36 mm. It has a diameter of 0.7 to 1.5 mm. It is imaged at an angle of less than 60 degrees between the ultrasound beam and the vessel lumen. The artery shows a medium-to-high resistance flow pattern, with a sharp systolic peak and a rapidly declining diastolic phase.<\/p>\n

Superior Orbital Vein Imaging: The SOV is localized in the superomedial orbit. Due to the lack of valves and the loose structure of the orbital veins, the venous flow waveform is affected by many external factors.<\/p>\n

Intraocular Tumors<\/h3>\n

Choroidal melanoma shows higher PSV (peak systolic velocity) and RI (resistance index) in the feeding vessels compared to orbital cavernous hemangiomas. Doppler parameters, such as a decrease in vascularized areas, a reduction in PSV, and an increase in tumor echogenicity, are used to monitor the response to radiation therapy.<\/p>\n

Arterial Occlusions<\/h3>\n

Central retinal artery occlusion or ophthalmic artery occlusion presents as sudden, painless vision loss.<\/p>\n

Ocular Ischemic Syndrome (OIS)<\/h3>\n

OIS is often characterized by the absence or reversal of end-diastolic flow in the central retinal artery and ophthalmic artery. This “steal phenomenon” is specific to underlying high-grade ICA occlusion or stenosis. Orbital Doppler helps with early diagnosis, which can potentially be life-saving.<\/p>\n

Arteritic Anterior Ischemic Optic Neuropathy<\/h3>\n

Patients with giant cell arteritis, without obvious ocular involvement, show a significant reduction in blood flow bilaterally in the orbit.<\/p>\n

Carotid-Cavernous Fistula<\/h3>\n

In cases of post-traumatic proptosis, SOV evaluation may show reversed flow indicating flow from the orbital apex to the globe. Waveform analysis may reveal arterialized high-velocity blood flow from a low-resistance vessel, indicating a high-flow fistula between the intracavernous part of the ICA and the cavernous sinus.<\/p>\n

Beh\u00e7et\u2019s Disease<\/h3>\n

Beh\u00e7et’s disease presents with widespread vasculitis involving orbital circulation. Vascular occlusion in the retina and choroid leads to a high RI and reduced flow velocities. Detecting blood flow changes before clinical signs appear helps initiate early treatment and achieve better visual outcomes.<\/p>\n","protected":false},"excerpt":{"rendered":"

What is Orbital Color Doppler Ultrasound? Orbital color Doppler ultrasound is an imaging method used to evaluate blood flow in the orbit. It assists in the diagnosis, prognosis, and monitoring of various ophthalmic diseases. Color Doppler ultrasound is a non-invasive technique used to create two-dimensional images of normal and pathological blood vessels. It is an […]<\/p>\n","protected":false},"author":1,"featured_media":3810,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-39","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-color-doppler-ultrasonography-cdus"],"_links":{"self":[{"href":"https:\/\/www.hekimoglugoruntuleme.com\/en\/wp-json\/wp\/v2\/posts\/39","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hekimoglugoruntuleme.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hekimoglugoruntuleme.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hekimoglugoruntuleme.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hekimoglugoruntuleme.com\/en\/wp-json\/wp\/v2\/comments?post=39"}],"version-history":[{"count":3,"href":"https:\/\/www.hekimoglugoruntuleme.com\/en\/wp-json\/wp\/v2\/posts\/39\/revisions"}],"predecessor-version":[{"id":3960,"href":"https:\/\/www.hekimoglugoruntuleme.com\/en\/wp-json\/wp\/v2\/posts\/39\/revisions\/3960"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.hekimoglugoruntuleme.com\/en\/wp-json\/wp\/v2\/media\/3810"}],"wp:attachment":[{"href":"https:\/\/www.hekimoglugoruntuleme.com\/en\/wp-json\/wp\/v2\/media?parent=39"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hekimoglugoruntuleme.com\/en\/wp-json\/wp\/v2\/categories?post=39"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hekimoglugoruntuleme.com\/en\/wp-json\/wp\/v2\/tags?post=39"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}