An eye and orbit ultrasound is a test that uses high-frequency sound waves to get measurements and produce detailed images of your eye and eye orbit. The orbit is the socket in your skull in which your eye sits.
Sometimes called eye studies, the procedure is usually performed by an ophthalmologist (a doctor specializing in diagnosing and treating eye disorders and diseases). Eye studies can also be performed by a technician in an office, outpatient center, or hospital.
During the test, a wand called a transducer is placed on the eyelid or the front surface of your eye. Because ultrasound can show details about the cornea and the structure of your eyes, eye studies are very useful in the diagnosis and treatment of a variety of eye conditions.
This is a quick and painless procedure that is not associated with serious side effects or risks.
Ultrasound provides a much more detailed view of the inside of your eye than is possible during a routine eye exam. Your eye doctor may order eye studies if you are experiencing unexplained problems with your eyes or if you have recently sustained an injury or trauma to the eye area.
This procedure is helpful in identifying tumors, neoplasms (abnormal growths), foreign substances, detachment of the retina, and in diagnosing diseases of the eye. For example, your doctor can use this procedure to measure the thickness and extent of a cancerous tumor and to assess treatment options.
Eye and orbit ultrasound also can be used to help diagnose and/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)
The ultrasound study of the eye can be performed in a hospital, an outpatient center, or in an ophthalmologist’s office. There are two parts to an eye and orbit ultrasound. The A-scan ultrasound is used to take measurements of the eye. The B-scan allows the doctor to see clearly into the back of the eye.
There is no preparation required for an eye and orbit ultrasound. You will be able to drive after the procedure, but you can arrange alternate transportation if you are concerned about your ability to see clearly. The procedure will take 15 to 30 minutes to complete.
There is no pain associated with ultrasound, although anesthetic drops will be used to numb your eye and minimize discomfort. Your eyes will not be dilated. The transducer will then be placed against the front surface of your eye. As the high-frequency sound waves travel through your eye, pictures of the structure of your eye are formed.
The A-scan is used to measure the eye. This is useful in determining the correct lens implant for cataract surgery.
While sitting upright in a chair, you will place your chin on a chin rest and look straight ahead. A probe that has been oiled will be placed against the front of your eye as it is scanned.
An A-scan can also be performed while you are lying down. In that case, a fluid-filled cup (waterbath) is placed against the surface of your eye as it is scanned.
The B-scan helps the doctor see the space behind the eye that can’t be seen otherwise. Cataracts and some other conditions make it difficult to see the back of the eye. The B-scan also aids in the diagnosis of tumors, retinal detachment, and other conditions.
For the B-scan, a gel will be put on the skin of your eyelids. You will be in a seated position with your eyes closed and will be directed to look in many directions as the probe is placed against your eyelids.
There are no serious risks associated with the eye ultrasound.
To avoid scratching your cornea, you are advised not to rub your numbed eyes following the procedure until the anesthetic has completely worn off. This should take between 15 and 30 minutes. Your vision may also be temporarily blurred during this time. You should be able to drive within a half hour, but you may feel more comfortable arranging for someone else to drive.
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
Your ophthalmologist will review the results with you.