Chapter 9: Ocular Motility

Question 1

Ocular Motility

Answer 1

The evaluation of eye movements and their disorders

Question 2

Rectus muscles

Answer 2

The 6 muscles that are attached to each eye to aid in movement
3 planes of movement:
1) Horizontal
2) Vertical
3) Torsional

Question 3

Superior Rectus Muscle

Answer 3

EOM attached to the upper side of the globe
3 functions:
1) Supraduction
2) Incyclotorision
3) Adduction
Innervated by Oculomotor nerve

Question 4

Inferior Rectus Muscle

Answer 4

EOM attached to the underside of the globe
3 functions:
1) Infraduction
2) Excyclotorsion
3) Adduction
Innervated by the Oculomotor nerve

Question 5

Medial Rectus Muscle

Answer 5

EOM attached to the inner side of the globe
Function
1) Adduction
Innervated by the Oculomotor nerve

Question 6

Lateral Rectus Muscle

Answer 6

EOM attached to the outer part of the globe
Function:
1) Abduction
Innervated by the Abducens nerve

Question 7

Superior Oblique Muscle

Answer 7

EOM attached to the upper/outer side of the globe
3 Functions:
1) Incyclotorsion=in and down
2) Depression
3) Adduction
Innervated by the Trochlear nerve

Question 8

Inferior Oblique Muscle

Answer 8

EOM attached to the lower, outer part of the globe
3 functions:
1) Excyclotorsion= up and out
2) Elevation
3) Abduction
Innervated by the Oculomotor nerve

Question 9

Primary Action

Answer 9

The strongest action of the EOM

Question 10

Secondary Action

Answer 10

The intermediate action of the EOM

Question 11

Tertiary Action

Answer 11

The weakest action of the EOM

Question 12

Cardinal Positions of Gaze

Answer 12

The 6 points to which a patient’s eyes are directed, t test the major function of each EOM

Positions:
Right and Up
Right
Right and Down
Left and Up
Left
Left and Down

Question 13

Agonist

Answer 13

The muscle that moves the eye into a particular direction of gaze

Question 14

Antagonist

Answer 14

The muscle in the same eye that opposes the action of the agonist muscle action

Question 15

Ductions

Answer 15

Eye movements of a single eye

Question 16

Versions

Answer 16

Eye movements of both eyes at the same time

Question 17

Oculomotor Nerve

Answer 17

The 3rd cranial nerve, which supplies the impulses that activate the superior, medial, and inferior rectus muscles, inferior oblique muscles, as well as the levator palpebrae and the pupil

Question 18

Trochlear Nerve

Answer 18

The 4th cranial nerve, which supplies the impulses to the superior oblique muscle.

Question 19

Abducens Nerve

Answer 19

The 6th cranial nerve, which supplies impulses to the lateral rectus muscle

Question 20

Conjugate

Answer 20

When the eye muscles move in the same direction,

Question 21

Disconjugate

Answer 21

When the eyes move in opposite directions simultaneously. The most important example of this is convergence

Question 22

Convergence

Answer 22

The coordinated movement of both eyes inward in order to view close by objects

Question 23

Strabismus

Answer 23

A misalignment of the eyes that may cause vision to be disturbed, and occurs when the EOMs do not work in a coordinated manner

Question 24

Cominant

Answer 24

A strabismus that is the same in all fields of gaze

Question 25

Incominant

Answer 25

A strabismus that has a different deviation in various gaze directions typically caused by either restriction or paralysis of EOMs

Question 26

Exo-

Answer 26

The outward deviation of the eye

Question 27

Eso-

Answer 27

The inward deviation of the eye

Question 28

Hypo-

Answer 28

The downward deviation of the eye

Question 29

Hyper-

Answer 29

The upward deviation of the eye

Question 30

Manifest

Answer 30

An abnormal eye alignment that is consistently present

Question 31

Latent

Answer 31

An abnormal eye alignment that is present only when fixation is interrupted

Question 32

Esotropia

Answer 32

The inward deviation of the eye in which the misalignment of the eye is present even when uncovered

Question 33

Esophoria

Answer 33

The inward deviation of the eye tat is present only when one eye is covered

Question 34

Corneal Light Reflex

Answer 34

A simple way to check eye alignment by observing how light reflects off of the corneas Also called the Hirschberg test

Question 35

Hirschberg Test

Answer 35

A simple test for eye alignment. If the reflection of the light in each cornea is centered in the pupil, then there is alignment

Question 36

Krimsky Test

Answer 36

A medical procedure to measure the angle of strabismus in patients with a horizontal strabismus A prism is placed in front of a patient's eye to correct the corneal light reflex

Question 37

Cover-Uncover Testing

Answer 37

A test performed by alternating covering and uncovering each eye to determine if a patient's eyes are misaligned (tropias)

Question 38

Alternate Cover Testing

Answer 38

A test performed by placing an occluder over one eye and then moving it to the other eye slowly in order to detect a tendency for the eyes to deviate while under the occluder (phorias)

Question 39

Prism and Alternative Cover Testing

Answer 39

A test to measure the quantity of ocular misalignment using prisms and an occluder

Question 40

Fusion

Answer 40

The blending by the brain of the separate images received by the 2 eyes so that a single image is perceived even when the eyes move

Question 41

Diplopia

Answer 41

Double vision, which can be cause by either strabismus or another eye condition

Question 42

Suppression

Answer 42

The brain's mechanism to avoid double vision by ignoring one eye The brain loses this ability after childhood

Question 43

Amblyopia

Answer 43

Decreased vision present without apparent abnormalities in the ocular anatomy and uncorrectable by spectacles or contact lenses. This results visual deprivation in early childhood

Question 44

Stereopsis

Answer 44

3D visual perception

Question 45

Titmus Stereopsis Test

Answer 45

A test for determining whether the patient has fine depth perception in terms of binocular cooperation