What is Transcranial Doppler (TCD)?
A Transcranial Doppler (TCD) is a quick (around 10 minutes), non-invasive, and painless test for patients of any age. It is a safe ultrasound that requires no dyes or radiation to look at all the major arteries and vessels; specifically from the carotid artery to the ophthalmic arteries, from an ocular health standpoint.
How does TCD work?
TCD is based on the principle of the doppler effect. The doppler probe creates ultrasound waves that move through blood cells within the vessels. The ultrasound waves create a recorded pattern and are analyzed by computer programs. Additionally, the information collected by the programs determines how the blood flows through the vessels; blood velocity. Blood velocity varies depending on age, gender, carbon dioxide levels, blood pressure, mental, and physical activity among other things. Differences in blood flow velocity should be interpreted considering these variables. TCD should be conducted with the patients at rest, not moving and not speaking.
Purpose of a TCD?
The purpose of this test is to assess patients’ risks of stroke, diagnosis of bleeding, and spasm of the blood vessels. A TCD measures the Ophthalmic Artery and Cerebral Vascular blood flow. As a result, an eye doctor can recommend a TCD when patients experience symptoms and conditions such as:
– Sudden Vision Loss
– Visual Field Defect and Disturbance
– History of Strokes
– Blurry Vision
– Double Vision
– Cardiovascular System Complications
– Carotid Artery Disease
– Hypertensive Retinopathy
– Diabetic Retinopathy
TCD is an essential and inexpensive tool used to diagnose and prevent a number of cerebrovascular disorders. Having this tool in our arsenal bridges the gap between a PCP/ Cardiologist and a Primary Eye Care Physician; allowing for transparency of information. All physicians have a better understanding of a patients’ systemic health and how that may affect his/her ocular health or vice versa.