Ocular and Orbit Ultrasonography, Ocular and Orbit Ultrasound
In eye ultrasound, a device called a transducer directs high-frequency sound waves (ultrasound) through the eye and the orbit (the bony cavity that contains the eye). The sound waves are reflected back to the transducer and electronically converted into graphic representations of internal structures that are displayed on a viewing monitor.
Two techniques are used for this test, often together: An A-scan converts the ultrasound echoes into waveforms that correspond to the positions of different structures, while a B-scan converts the echoes into two-dimensional images of ocular structures. These images can then be saved on film or video and reviewed for abnormalities.
Purpose of the Eye Ultrasound
- To examine the eye area and to measure the structures of the eye
- To detect abnormalities of the eye and orbit, such as vitreous hemorrhage (leakage of blood in the eye resulting from a ruptured blood vessel); detachment of the retina; ocular tumors or cysts; the presence of foreign bodies; or alterations in corneal or ocular shape due to disease, surgical procedures or trauma
- To evaluate the internal structures of the eye prior to planned surgical procedures, such as cataract removal with intraocular lens implantation
- To examine the eye when previous surgery, scarring, a cataract, or other factors preclude visual examination with an ophthalmoscope
Who Performs Eye Ultrasound
- An ophthalmologist or a technician trained in ultrasound
Special Concerns about Eye Ultrasound
Before the Eye Ultrasound
- If you wear contact lenses, remove them before the test.
- The examiner will administer topical anesthetic eye drops 5 to 10 minutes prior to the procedure.
What You Experience during Eye Ultrasound
- In most cases, you will sit in a chair, look straight ahead, and place your chin on a chin rest.
- Then a small probe is placed against the front of your eye.
- Eye ultrasound also may be performed while you lie back by placing a fluid-filled eye cup against your eye.
- A water-soluble gel is applied to the probe or eye cup to enhance sound wave transmission.
- The transducer is placed on the probe or eye cup and moved over its surface.
- The echoed sound waves are converted into waveforms on a viewing monitor and recorded for later analysis.
- The test takes about 5 minutes.
- You will be seated during this test and may be asked to "look" in many directions, usually with your eyes closed.
- A water-soluble gel is applied to your eyelid to enhance sound wave transmission and a B-scan probe is gently placed against your eyelids.
- The examiner moves a transducer back and forth over the surface of your eyelid to obtain various views of the targeted structures on a video monitor. You may be instructed to move your eye or change your gaze to provide different views.
- Once clear images are obtained, they are recorded on film or video for later analysis.
- The test takes about 5 minutes.
Risks and Complications of Eye Ultrasound
- Ultrasound is painless, noninvasive, and involves no exposure to radiation. There are no associated risks.
After the Eye Ultrasound
- Immediately after the test, the examiner removes the eye cups and/or the conductive gel from your eyelids.
- You are free to leave the testing facility and resume your normal activities.
- If anesthetic eye drops were administered, do not rub your eyes for at least 30 minutes to avoid injuring the cornea.
- Do not reinsert your contact lenses for at least 2 hours after the test.
Results of Eye Ultrasound
- A physician reviews the recorded ultrasound images for evidence of any abnormality in the eye or orbit.
- If a definitive diagnosis can be made based on these findings, your doctor will recommend appropriate treatment.
- In some cases, additional tests, such as a CT scan or an MRI, may be necessary to further evaluate any abnormal results.
The Johns Hopkins Consumer Guide to Medical Tests
Simeon Margolis, M.D., Ph.D., Medical Editor
Updated by Remedy Health Media