Head and eye Echoencephalogram
Head and eye Echoencephalogram

Eye and orbit ultrasound

Definition:

In this test, the eye is examined by ultrasound. The ultrasound uses high frequency sound waves that are emitted and received by a transducer (a hand-held instrument), and the sound waves penetrate the body. Based on the waves recorded, it is possible to determine if the structures being examined are functioning properly.

An echoencephalogram can also be used to examine the cerebral structures (for example, in checking for hydrocephalus), although it is more commonly used for eye disorders.    



Alternative Names:
Echoencephalogram - eye

How the test is performed:
The test is usually done in the ultrasound or radiology department. You will be lying down on the table. For the A-scan, the eye will be numbed with anesthetizing drops. A clear plastic eye cup is then placed over the eyeball. A lubricant is placed on the cup, and the transducer is positioned on the cup.

The B-scan is performed with the eyes closed. The lubricant is placed on the eyelid, and the transducer is positioned on the lubricant.
How to prepare for the test:
Adults:
No special preparation is necessary for this test.

Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experiences, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:
How the test will feel:
Your eye is numbed, so no discomfort is involved. You may be asked to look in a different direction to improve ultrasound image or to view different areas of the eye.
Why the test is performed:
The ultrasound helps evaluate the farthest part of the eyeball when there are cataracts. The test may help diagnose retinal detachment or other disorders and evaluate orbital lesions and intraocular lesions.
Normal Values:
The structures of the eyeball appear normal.
What abnormal results mean:
The test may reveal vitreous hemorrhage (bleeding into the transparent gel that fills the eyeball between the retina and the lens) and abnormalities, retinal detachment (a separation of the retina from the middle coat of the eyeball), tumors, retinoblastomas (a malignant growth of retinal cells), orbital lesions, foreign bodies, and inflammation.

Additional conditions under which the test may be performed:
What the risks are:
Do not rub your anesthetized eye until the anesthetic wears off or you may scratch the cornea.

Review Date: 5/7/2002
Reviewed By: A.D.A.M. editorial. Previous review: Galit Kleiner-Fisman MD, FRCP(C), Department of Neurology, University of Toronto, Toronto, Ontario, Canada. Review provided by VeriMed Healthcare Network (7/30/2001).
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