What is EOM movement?

EOM; Extraocular movement; Ocular motility examination. Extraocular muscle function testing examines the function of the eye muscles. A health care provider observes the movement of the eyes in eight specific directions. The eye is the organ of sight, a nearly spherical hollow globe filled with fluids (humors).

How do you assess EOM?

EOMs are most easily assessed by having the patient follow an object to move the eyes to 6 positions of gaze using the standard “H” pattern (Fig. 8).

What is EOM weakness?

INTRODUCTION. Myasthenia gravis (MG) is an autoimmune disease characterized by fatigability and fluctuating muscle weakness that usually begins in ocular muscles [1]. The affected ocular muscles can be subdivided in muscles that move the eyeball (extraocular muscles; EOM), the muscle that elevates the upper eyelid (m.

What are extraocular movements?

The extraocular muscles execute eye movements and are innervated by three cranial nerves. Contraction of the medial rectus pulls the eye towards the nose (adduction or medial movement). Contraction of the lateral rectus pulls the eye away from the nose (abduction or lateral movement).

What are the 6 cardinal fields of gaze?

You are now familiar with the 6 cardinal directions of gaze (right/up; right; right/down; left/up; left; left/down), as well as the remainder of the yoked eye movements (straight up; straight down; convergence).

How to diagnose extraocular eye movement disorders?

Extraocular eye movement disorders are relatively common and may be a significant source of discomfort and morbidity for patients. The presence of restricted eye movement can be detected clinically with quick, easily performed, noninvasive maneuvers that assess medial, lateral, upward, and downward gaze.

Why do we need to know about extraocular muscles?

Because so much of vestibular testing relies on the interpretation of eye movements, it is paramount that the vestibular clinician understand how the eyes move, their limitations of motion, eye movement’s impact on vision, and potential disorders of the extraocular muscles (EOM).

Is it possible to have extraocular eye dysmotility?

Extraocular eye movement disorders are relatively common and may be a significant source of discomfort and morbidity. Ocular dysmotility may occur as an isolated finding or as a secondary manifestation of a broader disease process.

How does Sherrington’s law relate to extraocular muscles?

Sherrington’s Law is quite reasonable then: an increase in innveration to the agonist muscle (making a desired movement) must be accompanied by an equal decrease in innervation to that muscle’s antagonist (the muscle that would do the opposite). This law nicely illustrates the relationship between paired agonist/antagonist extraocular muscles.