Eye movements

Question 1

What are the six extra-ocular muscles?

Answer 1

Lateral Rectus
Medial Rectus
Superior oblique
Inferior oblique
Superior rectus
Inferior rectus

Question 2

Which extra-ocular muscles are innervated by the oculomotor nerve?

Answer 2

Medial rectus
Superior Oblique
Inferior Oblique
Inferior rectus

Question 3

Which nerve innervates the superior oblique?

Answer 3

trochlear nerve

Question 4

Which extra-ocular muscle is innervated by the abducens nerve?

Answer 4

Lateral rectus

Question 5

What is duction?

Answer 5

Eye movement in one eye

Question 6

What term describes simultaneous movement of both eyes in the same direction?

Answer 6

Version

Question 7

What is vergence?

Answer 7

Simultaneous movement of both eyes in the opposite direction

Question 8

What is convergence?

Answer 8

Simultaneous adduction (inward) movement in both eyes when viewing a near object

Question 9

What is saccade?

Answer 9

Short fast, burst up to 900 degrees/second

Voluntary and involuntary

Question 10

What are the four types of saccade?

Answer 10

Reflexive saccade to external stimuli
Scanning saccade
Predictive saccade to track objects
Memory guided saccade

Question 11

What is smooth pursuit?

Answer 11

Sustains slow movement (up to 60 degrees/s)
Driven by motion of a moving target across the retina
-Involuntary

Question 12

What is the function of the superior rectus?

Answer 12

Elevation of the eyeball

Adduction

Question 13

What is the function of the inferior rectus?

Answer 13

Depression of the eyeball

Adduction

Question 14

In what position are the vertical rectus muscles aligned?

Answer 14

When the eye is in an abducted position.

Anterior-posterior axis of the eye is aligned with the insertion of the vertical muscles

Question 15

In what position will the superior rectus elevate the eye maximally?

Answer 15

Abducted position

Question 16

What is the function of the lateral rectus?

Answer 16

Abduction of the eyeball

Moves eye toward the outside of the head

Question 17

What is the function of the medial rectus?

Answer 17

Adduction of the eyeball

Attached on the nasal side of the eye, moves eye toward the middle of the head.

Question 18

What is the function of the superior oblique?

Answer 18

Abducting, depression and internally rotating the eye.

Question 19

What is the function of the inferior oblique?

Answer 19

Elevate and adduct the abduct

Question 20

Which muscle raises the eyelid?

Answer 20

Levator palebrae superioris

Question 21

Which nerve innervates the levator palpebrae superioris?

Answer 21

Oculomotor nerve

Question 22

Which specific nerve innervates the superior rectus muscle?

Answer 22

The superior oculomotor nerve

Question 23

Which specific nerve innervates the medial, inferior rectus and the inferior oblique?

Answer 23

Inferior oculomotor nerve

Question 24

Which position is the lateral rectus muscle best tested?

Answer 24

In the abducted position

Question 25

Which position is the medial rectus best tested?

Answer 25

In the adducted position

Question 26

Which position is the superior rectus best tested in?

Answer 26

Elevated and abducted position

Question 27

Which position is the inferior rectus best tested in?

Answer 27

Depressed and abducted position

Question 28

Which position is the inferior oblique best tested in?

Answer 28

Elevated and adducted

Question 29

Which position is the superior oblique best tested in?

Answer 29

Depressed and adducted

Question 30

What is supraduction?

Answer 30

Elevation in one eye

Question 31

What is supraversion?

Answer 31

Elevation in both eyes

Question 32

What is infraduction?

Answer 32

Depression in one eye

Question 33

Depression in both eyes is referred to as what?

Answer 33

Infraversion

Question 34

What is dextroversion?

Answer 34

Eye movements to the right | Right abduction and left adduction

Question 35

What is levoversion?

Answer 35

Right adduction and left abduction Eye movements to the left

Question 36

What is torsion?

Answer 36

Rotation of the eye around the anterior posterior axis of the eye.

Question 37

Which extra-ocular muscles are not affected in a third nerve palsy?

Answer 37

Superior oblique and lateral rectus

Question 38

What is the eye movements in a patient with third nerve palsy?

Answer 38

Down and out considering the lateral rectus abducts and the superior oblique depresses the eyeball - over action of the two unopposed muscles.

Question 39

What happens to the eyelid in a third nerve palsy?

Answer 39

ptosis, drooping of the eye lid as the levator palpebrae superioris is affected.

Question 40

Which nerve is affected in a sixth-nerve palsy?

Answer 40

Lateral rectus

Question 41

What happens to eye movements in a sixth nerve palsy?

Answer 41

Affected eye is unable to abduct and thus deviates inwards.

Question 42

What is nystagmus?

Answer 42

Refers to the oscillatory movement of the eye

Question 43

What is an optokinetic nystagmus?

Answer 43

Smooth pursuit and fast phase reset saccade

Question 44

Which eye reflex is useful when testing the visual acuity in pre-verbal children?

Answer 44

Optokinetic nystagmus reflex Observes the presence of nystagmus movement in response to moving grating patterns of various spatial frequencies.

Question 45

What is the optokinetic nystagmus reflex?

Answer 45

Opto-kinetic Nystagmus is a form of physiological nystagmus, triggered by the presentation of a constantly moving grating pattern. The eyes track along the grating motion, with smooth pursuit up to a limit, and resets the eye position to the centre, with a burst of fast saccade motion. This results in cycles of slow phase smooth pursuit, alternating with fast phase reset saccade in the opposite direction.