Ocular Motility Testing Flashcards
What is the “center of rotation of the eyeball?
The motion of the globe around a pivot point.
How is each eye suspended in the orbit?
By the EOMs and a complicated system of connective tissue and orbital fat.
How many EOMs are in each eye?
6.
How many cranial nerves are involved in the motor control of the EOMs?
3.
How many oblique muscles are found in each eye? What are they called?
- One Superior oblique and the other inferior oblique.
How many recti are found in each each? What are they called?
- Medial, lateral, superior, and inferior rectus.
The medial rectus is controlled by which cranial nerve?
Inferior division of Oculomotor Nerve (III).
The lateral rectus is controlled by which cranial nerve?
Abducens Nerve (VI).
The superior rectus is controlled by which cranial nerve?
Superior division of Oculomotor Nerve (III).
The inferior rectus is controlled by which cranial nerve?
Inferior division of Oculomoter Nerve (III).
The superior oblique is controlled by which cranial nerve?
Trochlear Nerve (IV)
The inferior oblique is controlled by which cranial nerve?
Inferior division of Oculomoter Nerve (III).
The levator palpebrae superioris is controlled by which cranial nerve?
Superior division of Oculomotor Nerve (III).
The line connecting center of the eye and point of fixation is called what?
Line of sight.
What term is used sometimes as a synonym for the straight ahead position?
Primary position.
What term is used to identify a position of view in which one of the EOMs has it’s main action?
Secondary or “Cardinal” position.
What are two examples of versions?
Saccades and pursuits.
What are two examples of vergence movements?
Convergence and divergence.
There are 3 types of eye movements. What are they called?
Versions, vergence movements, and duction.
True or False: Versions involve the rotation of the two eyes such that their line of sight move in opposite directions.
False. Same directions.
True of False: Vergence involve the rotation of the two eyes such that their line of sight move in opposite directions.
True.
Binocular movements in which the two eyes move synchronously and symmetrically in the same direction is called what?
Versions.
What are saccadic eye movements?
Movements that place the object of interest on the fovea rapidly.
Moving the eyes from one object to another. Voluntarily or as a reflex triggered by the appearance by an object in the peripheral field. Voluntary shift in fixation from one point to another. What is being described?
Saccadic eye movement in versions.
Where does the control of saccades occur in the brain?
Frontal lobe.
What is an example of saccadic eye movements?
Reading.
What is the function of pursuit eye movements?
To maintain fixation on an object of interest.
Stimulus is triggered by the movement of the object near the fovea. Speed slow and smooth. What is being described?
Pursuit eye movements in versions.
Where does the control of pursuits occur in the brain?
Occipital lobe.
Medial rectus contracts in both eyes, pulling the eyes to the nose. What is being described?
Convergent vergence.
(During eye converged) Medial rectus relaxes and/or later rectus contracts, pulling the eyes out and away from the nose. What is being described?
Divergent vergence.
Rotation of one eye under monocular conditions is called?
Duction.
What are two examples of duction?
ABduction and ADduction.
Movement of the eye away from the nose is called what?
ABduction.
Movement of the eye toward the nose is called what?
ADduction.