Eye and orbit ultrasound Health Article

Definition

An eye and orbit ultrasound is a test to look at the eye area, and to measure the size and structures of the eye.

Alternative Names

Echography - eye; Ultrasound - eye

How the test is performed

The test is usually done in the ophthalmologist’s office or the ophthalmology department.

You usually sit in a chair. Your eye is numbed with medicine (anesthetic drops). The ultrasound wand (transducer) is placed against the front surface of the eye.

The ultrasound uses high-frequency sound waves that travel through the eye. Reflections (echoes) of the sound waves form a picture of the structure of the eye. The test takes about 15 minutes.

There are two types of scans:

• For the A-scan, you will look straight ahead
• For the B-scan, you will look in many directions

How to prepare for the test

No special preparation is needed for this test.

How the test will feel

Your eye is numbed, so you shouldn't have any discomfort. You may be asked to look in different directions to improve the ultrasound image or so it can view different areas of your eye.

A lubricant placed on the ultrasound wand may run on your cheek, but you won't feel any discomfort or pain.

Why the test is performed

The ultrasound can examine the farthest part of the eyeball when you have cataracts or other conditions that make it hard for the doctor to look into your eye. The test may help diagnose retinal detachment or other disorders when the eye is not clear and the ophthalmologist cannot use routine examining equipment.

An A-scan ultrasound measures the eye to determine the proper power of a lens implant before cataract surgery.

Normal Values

The structures of the eyeball appear normal.

What abnormal results mean

The test may show:

• Bleeding into the clear gel that fills the eyeball between the retina and the lens (vitreous hemorrhage)
• Cancer of cells in the retina (retinoblastoma) or cancer under the retina or other parts of the eye (melanoma)
• Damaged tissue (lesions) in the bony socket that protects the eye (orbit)
• Foreign bodies
• Separation of the retina from the back of the eye (retinal detachment)
• Swelling (inflammation)

What the risks are

To avoid scratching the cornea, do not rub the numbed eye until the anesthetic wears off (about 15 minutes). There are no other risks.