Extraocular muscle function testing
Extraocular muscle function testing examines the function of the eye muscles. A health care provider observes the movement of the eyes in six specific directions.
EOM; Extraocular movement; Ocular motility examination
How the Test is Performed
You are asked to sit or stand with your head up and looking straight ahead. Your health care provider will hold a pen or other object about 16 inches in front of your face. The provider will then move the object in several directions and ask you to follow it with your eyes, without moving your head.
A test called a cover/uncover test may also be done. You will look at a distant object and the person doing the test will cover the other eye, then after a few seconds, uncover it. You will be asked to keep looking at the distant object. How the eye moves after it is uncovered may show problems. Then the test is performed with the other eye.
How to Prepare for the Test
No special preparation is necessary for this test.
How the Test will Feel
The test involves only normal movement of the eyes.
Why the Test is Performed
This test is performed to evaluate weakness or other problem in the extraocular muscles. These problems may result in double vision or rapid, uncontrolled eye movements.
Normal movement of the eyes in all directions.
What Abnormal Results Mean
Eye movement disorders may be due to abnormalities of the muscles themselves. They may also be due to problems in the sections of the brain that control these muscles. Your health care provider will talk to you about any abnormalities that may be found.
There are no risks associated with this test.
Rapid uncontrolled eye movements, nystagmus, may occur slightly when shifting the eyes in an extreme sideways direction. This is normal and stops quickly.
American Academy of Ophthalmology Preferred Practice Patterns Committee. Preferred Practice Pattern Guidelines. Comprehensive Adult Medical Eye Evaluation - 2010. Available at one.aao.org/preferred-practice-pattern/comprehensive-adult-medical-eye-evaluation--octobe. Accessed February 27, 2015.
Baloh RW, Jen J. Neuro-ophthalmology. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 432.
Demer JL. Eye movements and positions. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 2013 ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013:vol 1, chap 2.
Griggs RC, Jozefowicz RF, Aminoff MJ. Approach to the patient with neurologic disease. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 403.
Reviewed By: Franklin W. Lusby, MD, ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.