An eye and orbit ultrasound uses high-frequency sound waves to measure and produce detailed images of your eye and eye orbit. The orbit is the socket in your skull that holds your eye. This test provides a much more detailed view of the inside of your eye than is possible during a routine eye exam.
Sometimes called eye studies, an ultrasound technician or an ophthalmologist usually performs the procedure. An ophthalmologist is a doctor who specializes in diagnosing and treating eye disorders and diseases.
Eye studies can be done in an office, outpatient imaging center, or hospital.
Your eye doctor may order eye studies if you’re experiencing unexplained problems with your eyes or if you’ve recently sustained an injury or trauma to the eye area.
This procedure is helpful in identifying issues with the eyes and diagnosing eye diseases. For example, some issues the test can help identify include:
- tumors or neoplasms involving the eye
- foreign substances
- detachment of the retina
An eye and orbit ultrasound can also be used to help diagnose or monitor:
- glaucoma (a progressive disease that can lead to vision loss)
- cataracts (cloudy areas in the lens)
- lens implants (plastic lenses implanted in the eye after the natural lens has been removed, usually due to cataracts)
Your doctor can also use this procedure to measure the thickness and extent of a cancerous tumor and determine treatment options.
Procedure and Preparation
An eye and orbit ultrasound requires no specific preparation.
No pain is associated with an eye and orbit ultrasound. Anesthetic drops will be used to numb your eye and minimize discomfort. Your eyes will not be dilated.
Your vision may be temporarily blurred during the test. You should be able to drive a half hour after the procedure, but you may feel more comfortable arranging for someone else to drive.
Your eye doctor will advice you not to rub your eyes after the procedure until the anesthetic has completely worn off. This is so you don’t scratch your cornea.
There are two parts to an eye and orbit ultrasound. The A-scan ultrasound takes measurements of the eye. The B-scan allows the doctor to see clearly into the back of the eye. The combined procedure (A and B scans) will take 15 to 30 minutes to complete.
The A-scan measures the eye. This is useful in determining the correct lens implant for cataract surgery.
While sitting upright in a chair, you’ll place your chin on a chin rest and look straight ahead. A probe that has been oiled will be placed against the front portion of your eye as it’s scanned.
An A-scan can also be performed while you’re lying down. In that case, a fluid-filled cup, or water bath, is placed against the surface of your eye as it’s scanned.
The B-scan helps your doctor see the space behind the eye. Cataracts and other conditions make it difficult to see the back of the eye. The B-scan also helps in the diagnosis of tumors, retinal detachment, and other conditions.
During a B-scan, you’ll be in a seated position with your eyes closed. Your eye doctor will put a gel on your eyelids. They’ll tell you to keep your eyes closed while moving them in many directions. Your eye doctor will place the probe against your eyelids.
This is a quick and painless procedure with no serious side effects or risks.
Your ophthalmologist will review the results with you.
Your doctor will make sure the measurements of your eye taken from the A-scan are within normal range.
The B-scan will give your doctor structural information about your eye. If results are abnormal, your doctor will need to determine the cause.
Some conditions that may be revealed by the B-scan include:
- foreign bodies in the eye
- detachment of the retina
- damaged tissue or injury to the eye socket (orbit)
- vitreous hemorrhage (bleeding into the clear gel, called vitreous, that fills the back of the eye)
- cancer of the retina, under the retina, or in other parts of the eye
Once they reach a diagnosis, your doctor will work to determine the best course of treatment for you.