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

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.

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.

No special preparation is needed for this test.

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.