Ocular Motility Pt. 1

Question 1

How many extraocular muscles are attached to the eyeball?

Answer 1

6

Question 2

What are the names of the 6 extraocular muscles?

Answer 2

4 rectus muscles (inferior, superior, lateral, and medial) and 2 oblique muscles (inferior and superior)

Question 3

The manner in which these extraocular muscles “grip” the eyeball allows it to move in 3 different planes: _____, _____, and _____

Answer 3

Horizontal, Vertical, and Torsional

Question 4

What are the Cardinal positions of gaze?

Answer 4

right and up, right, right and down, left and up, left, left and down

Question 5

The muscle that moves the eye in a particular direction of gaze is called the _______

Answer 5

Agonist

Question 6

The muscle of the same eye that opposes that action is call the _____

Answer 6

Antagonist

Question 7

What are the 3 cranial nerves that extend from the brainstem to the 6 extraocular muscles?

Answer 7

1. Oculomotor/3rd cranial nerve
2. Trochlear/4th cranial nerve
3. Abducens/6rg cranial nerve

Question 8

What does the oculomotor/3rd cranial nerve power?

Answer 8

superior rectus, inferior rectus, medial rectus, and inferior oblique muscles

Question 9

What does the trochlear/4th cranial nerve power?

Answer 9

superior oblique muscle

Question 10

What does the abducens/6th cranial nerve power?

Answer 10

lateral rectus muscle

Question 11

Areas in the brainstem regulate _____________ to yoke muscles so that the right medial rectus and the left medial rectus are afforded equal nerve supply power to move the eyes smoothly and simultaneously to the left

Answer 11

the distribution of power

Question 12

When both eyes move in the same direction, the movements are said to be _______

Answer 12

Conjugate

Question 13

_________ eye movements are simultaneous movements of both eyes in opposite directions

Answer 13

Disconjugate

Question 14

The most important disconjugate movement is _______, which occurs when both eyes move inward

Answer 14

Convergence

Question 15

Abnormal eye alignments are also referred to as ______

Answer 15

Strabismus

Question 16

________ eye misalignments are constant in all fields of gaze

Answer 16

Comitant

Question 17

_______ eye misalignments have different amounts of deviation in different fields of gaze

Answer 17

Incomitant

Question 18

Strabismus is characterized as ___, ____, ____, or _____

Answer 18

Eso- (eyes go in), Exo- (eyes go out), hypo- (one eye goes down), or hyper- (one eye goes up)

Question 19

Strabismus can be ______, consistently present, or ______, present only when fixation is interrupted

Answer 19

Manifest/Latent

Question 20

All _______ are manifest deviations and all _______ are latent deviations

Answer 20

-Tropias/-Phorias

Question 21

What are the 2 primary tests used to evaluate eye movement abnormalities?

Answer 21

Corneal light reflex observation and Cover testing

Question 22

The ________ test involves observing the position of the corneal light reflex relative to the pupil

Answer 22

Hirschberg

Question 23

The ______ test uses prisms to “balance” the light reflexes in the center of the pupils to more accurately measure the deviation

Answer 23

Krimsky

Question 24

This kind of test involves the use of an occluder to cover one eye and thereby disrupt its fixation.

Answer 24

Cover-Uncover testing

Question 25

If there is no movement observed in the cover-uncover test, then an _________ test is performed to detect a phoria. (this test disrupts the patients ability to fuse by not allowing them to use both eyes at the same time)

Answer 25

Alternate cover test

Question 26

This test is used to measure the quantity of ocular misalignment using prisms and an occluder

Answer 26

Prism and alternate cover test

Question 27

The unit of measure of the refractive power of a prism

Answer 27

Prism Diopter

Question 28

Strabismus prevents _______, the ability of the brain to merge the 2 images received from each eye into a single binocular image

Answer 28

Fusion

Question 29

Adults complain of _________ when their fusion is disrupted

Answer 29

Diplopia