Week 2.01 Ocular Motility

Question 1

Definitions of incomitant vs comitant

Answer 1

Incomitant:
- varies in size with the direction of
gaze
- varies depending upon which eye fixates

Comitant: remains constant with gaze direction

Question 2

What’s the difference between congenital and acquired incomitant deviations

Answer 2

Congenital - developmental abnormality e.g. Duane’s retraction syndrome, browns syndrome

Aquired - due to injury or disease, long standing?, recent onset?

Question 3

What’s the difference between paralysis and palsy

Answer 3

Paralysis is complete loss of muscle action

Palsy/paresis is incomplete loss of muscle action , partial loss

Question 4

What are the other classifications and what do they mean

Answer 4

Neurogenic - innervation of EOMs
Myogenic - pathology of EOMs
Mechanical - something physically stopping

Question 5

What are the Extra ocular muscles and what cranial nerves are they innervated by

Answer 5

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

SO4 LR6 the rest are 3rd cranial nerve

3rd nerve - oculomotor
4th nerve - trochlear nerve
6th - abducens

Question 6

Define ductions

Answer 6

Monocular eye movements into/from cardinal position (straight ahead)

Question 7

Define versions

Answer 7

Conjugate binocular eye movements that allow visual axes to move in parallel

Question 8

Define vergences

Answer 8

Binocular eye movements which allow visual axes to cross. E.g. convergence and divergence

Question 9

What are Torsions

Answer 9

Rotational movements

Question 10

What do we do before checking any ocular motility

Answer 10

Observe the eyes in the primary position. Check any manifest deviations. Could do hirshberg test to check corneal reflex are both equal

Question 11

What is the movement called when both eyes look up and both eyes look down

Answer 11

Supraduction - elevation
Infraduction - depression

Question 12

What is the eye movements called when both eyes look to the px right. What does each eye do

Answer 12

Dextroversion
RE abducts
LE adduction

Question 13

What is the movement called when both eyes look to the px left

Answer 13

Laevo-version
RE adducts
LE abducts

Question 14

What is the movement when both eyes look in

Answer 14

Convergence
RE adducts
LE adducts

Question 15

What is the main action of the lateral rectus

Answer 15

Abduction
Move the eye temporally
Innervation: abducens 6th nerve

Question 16

What is the main action of the medial rectus

Answer 16

Main action: adduction
Moves eye nasally
Innervation: 3rd/oculomotor nerve

Question 17

What is the main and secondary action of superior rectus

Answer 17

Main action: supraduction
Secondary action: incycloduction - turns eye in towards nose, adduction
Innervation: 3rd nerve

Question 18

What is the main and secondary actions of the inferior rectus

Answer 18

Main action: infraduction
Secondary: excyloduction & adduction
Innervation: 3rd nerve

Question 19

What is the main and secondary actions of the superior oblique

Answer 19

Main action: infraduction
Secondary: incycloduction & abduction
Innervation: trochlear nerve 4th

Question 20

What are the main and secondary actions of the inferior oblique

Answer 20

Main action: supraduction
Secondary: excycloduction & abduction
Innervation: 3rd nerve

Question 21

What is a useful way of remembering secondary actions

Answer 21

RAD SIN

Recti adduct….therefore obliques abduct
Superiors intort….therefore inferiors extort

And remember lateral and medial rectus do not have secondary actions

Question 22

What muscles does the eyes use when looking to the right and what about left

Answer 22

Right: RLR & LMR
Left: RMR & LLR

Question 23

What muscles are being used when px looked up and right…how about up and left

Answer 23

Up and right: LIO, RSR
Up and left: RIO,LSR

Question 24

What muscles are being used when px looks down and right, how about down and left

Answer 24

Down and right: LSO & RIR
Down and left: RSO & LIR

Question 25

When doing the ocular motility test what does each eye we want to do when we check the diagonal positions

Answer 25

Isolate the main muscle action and minimise the secondary action

So get px to look across first then up

Question 26

What is the main symptoms that will be noticed my patients during ocular motility test

Answer 26

Diplopia either side by side or one on top of the other

Question 27

What are yoke muscles

Answer 27

One from each eye that work together and have the same level of innervation

Just think it through using the positions

Question 28

What are contralateral synergists and ipsilateral antagonists

Answer 28

Contralateral synergists - from each eye doing the same thing
Ipsilateral antagonist - same eye, against each other

Question 29

How to conduct ocular motility test

Answer 29

Pen torch held about 50mm away from px
Instruct px to follow torch keeping heads still
Move torch below in star pattern
Px instructed to report any discomfort or diplopia
If diplopia present determine whether it is horizontal or vertical and find the area over which it is greatest
Examiner also must careful watch for any muscle restriction
Isolate img to find out which eye sees which image can be done with red or green filters

Question 30

How can u check which eye sees which spot of light in diplopia img

Answer 30

Use a red filter over one eye and ask px what colour the higher image is if its a vertical diplopia or which one is to the left most if looking left or which is to the right most if looking right

Question 31

What happens if u see more than one potion for diplopia

Answer 31

Find where diplopia/seperation is greatest

Question 32

If px sees diplopia on both opposite sides what does that mean

Answer 32

On opp sides usually means bilateral under action