Ocular Motility Flashcards
What does the ocular motility test assess?
The function of the extraocular muscles and their innervating cranial nerves for overaction, underaction, or restrictions in eye movement.
What is the first step in the procedure of the ocular motility test?
Patient positioning: Sit directly in front of the patient at eye level and ensure the patient keeps their head still.
What should be used as a fixation target during the ocular motility test?
A penlight or small object held about 40 cm away from the patient’s face.
What pattern is used to move the fixation target during the test?
An ‘H’ or star pattern to cover the nine diagnostic positions of gaze.
What should the examiner observe during the ocular motility test?
Smoothness of movement, range of motion, signs of overaction or underaction, nystagmus, or any restriction.
What does underaction of an eye indicate?
Weakness or paresis of the agonist muscle.
What does overaction of an eye typically suggest?
Compensatory mechanism of a muscle moving excessively in certain gaze.
What does diplopia indicate during the ocular motility test?
Muscle imbalance or nerve palsy.
What neurological issue might nystagmus indicate?
Possible neurological issues.
Which cranial nerves innervate the extraocular muscles?
CN III (oculomotor), CN IV (trochlear), and CN VI (abducens).
What is the action of the lateral rectus muscle?
Moves the eye outward (abduction) — innervated by CN VI.
What is the action of the medial rectus muscle?
Moves the eye inward (adduction) — innervated by CN III.
What muscle elevates the eye when it’s abducted?
Superior rectus (SR) — innervated by CN III.
What is the function of the inferior oblique muscle?
Elevates the eye when it’s adducted and extorts the eye — innervated by CN III.
When looking to the right, which muscles are engaged?
Right lateral rectus (abducts right eye) and left medial rectus (adducts left eye).
What happens during pure upgaze?
Tests both superior rectus and inferior oblique muscles bilaterally.
What does failure to elevate in upgaze when abducted suggest?
Superior rectus underaction.
In a right superior oblique palsy, what visual symptom may occur?
Vertical diplopia due to failure to depress properly in adduction.
Fill in the blank: The eye moves excessively in a certain gaze, indicating _______.
[overaction of a muscle]
