An eye and orbit ultrasound is a test to look at the eye area, and to measure the size and structures of the eye.
Echography - eye orbit; Ultrasound - eye orbit; Ocular ultrasonography; Orbital ultrasonography
The test is usually done in the ophthalmologist's office or the ophthalmology department of a hospital or clinic.
Your eye is numbed with medicine (anesthetic drops). The ultrasound wand (transducer) is placed against the front surface of the eye.
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 test takes about 15 minutes.
There are two types of scans -- A-scan and B-scan.
For the A-scan:
For the B-scan:
No special preparation is needed for this test.
Your eye is numbed, so you shouldn't have any discomfort. You may be asked to look in different directions to improve the ultrasound image or so it can view different areas of your eye.
A lubricant placed on the ultrasound wand may run on your cheek, but you won't feel any discomfort or pain.
Your doctor may order this test if you have cataracts or other eye problems.
An A-scan ultrasound measures the eye to determine the right power of a lens implant before cataract surgery.
A B-scan is done to look at the inside part of the eye or the space behind the eye that can't be seen directly. This may occur when you have cataracts or other conditions that make it hard for the doctor to see into the back of your eye. The test may help diagnose retinal detachment, tumors, or other disorders.
For an A-scan, measurements of the eye are in the normal range.
For a B-scan, the structures of the eye and orbit appear normal.
A B-scan may show:
To avoid scratching the cornea, do not rub the numbed eye until the anesthetic wears off (about 15 minutes). There are no other risks.
Fisher YL, Nogueira F, Salles D. Diagnostic ophthalmic ultrasonography. In: Tasman W, Jaeger EA, eds. Duane's Foundations of Clinical Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 108.
Coleman DJ, Silverman RH, Rondeau MJ, Daly SW, Lloyd HO. Evaluation of the posterior chamber, vitreous and retina with ultrasound. In: Tasman W, Jaeger EA, eds. Duane's al Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 3.
Massoud TF, Cross JJ. The orbit. In: Adam A, Dixon AK, Grainger RG, Allison DJ, eds. Grainger & Allison's Diagnostic Radiology. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 61.
Fisher YL, Klancnik Jr JM, Rodriguez-Coleman H, et al. Contact B-scan ultrasonography. In: Yanoff M, Duker JS, eds. Yanoff & Duker: Ophthalmology. 3rd ed. Philadelphia, Pa: Mosby Elsevier; 2008:chap 6.7.