Carotid Ultrasound (Doppler)

Carotid ultrasound uses sound waves to visualize the carotid arteries in the neck. It can detect narrowing (stenosis) or plaques that may affect blood flow to the eyes and brain.

Why It's Done

• Evaluate transient vision loss (amaurosis fugax)
• Assess for embolic source after retinal artery occlusion
• Screen for carotid disease
• Evaluate before certain surgeries
• Follow known carotid stenosis

What It Evaluates

Carotid Arteries

• Common carotid
• Internal carotid (supplies eye and brain)
• External carotid
• Bifurcation (where they divide)

What It Shows

• Degree of narrowing (stenosis percentage)
• Plaque presence and characteristics
• Blood flow velocity
• Direction of flow

What to Expect

Before the Test

• No special preparation
• Can eat and drink normally
• Take usual medications

During the Test

• Lie on back with neck extended
• Gel applied to neck
• Ultrasound probe moved along neck
• May hear "whooshing" (blood flow sounds)
• Completely painless
• Takes 20-30 minutes

After the Test

• Resume normal activities
• No recovery time needed
• Results available quickly

Results and Next Steps

Normal

• No significant narrowing
• Normal blood flow

Significant Stenosis

• May need further imaging (CTA, MRA)
• Consider medical management or intervention
• Depends on degree and symptoms

Importance in Eye Disease

Carotid disease can cause:

• Temporary vision loss in one eye
• Retinal artery occlusion
• Ocular ischemic syndrome
• Important to identify and treat