An eye and orbit ultrasound is a test to look at the eye area. 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 precise size of the eye and any structures in the eye can be measured.

The test is usually done in the ophthalmologist's office or the ophthalmology department. You usually sit in a chair. The eye will be numbed with anesthetizing drops. The ultrasound wand (transducer) is placed against the front surface of the eye.

There are two types of scans:

For the A-scan, you will be asked to look straight ahead.

If a B-scan is performed, you will be asked to look in multiple directions.

No special preparation is necessary for this test.

Your eye is numbed, so no discomfort is involved. You may be asked to look in a different directions to improve the ultrasound image or to view different areas of the eye.

A lubricant placed on the transducer may run on your cheek, but there will be no discomfort or pain. The test takes about 15 minutes.

The ultrasound helps evaluate the farthest part of the eyeball when you have cataracts or other reasons that make it hard to look into your eye. The test may help diagnose retinal detachment or other disorders when the eye is not clear and the ophthalmologist can not use routine examining equipment. An A-scan ultrasound measures the eye for the proper power of a lens implant before cataract surgery.

The structures of the eyeball appear normal.

The test may reveal:

• Vitreous hemorrhage (bleeding into the transparent gel that fills the eyeball between the retina and the lens)
• Retinal detachment (separation of the retina from the middle coat of the eyeball),
• Tumors such as retinoblastoma (cancerous growth of retinal cells) or melanoma (cancerous growth under the retina or other parts of the eye)
• Lesions in the orbit (the bony socket that protects the eye)
• Foreign bodies
• Inflammation

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