Clincial Evaluation Of Eye Movements

Question 1

Ductions

Answer 1

Movement when one eye is covered

Have patient cover one eye

Excursion of one eye

Question 2

Versions

Answer 2

Excursions of both eyes

Simply with both eyes open

Question 3

Pursuit

Answer 3

Keeps image on fovea, 30-40 deg/sec, parietal-temporal areas

Assess: follow finger

Slow eye movements

Parkinson’s can affect this

Question 4

Saccades

Answer 4

Bring image on to fovea

Assess: switch fixation finger- nose note speed, accuracy

Bring an object of interest into your fovea (a rapid eye movement, designed to find whatever it is that is of immediate interest to you)

Question 5

Vergence

Answer 5

Keeps visual fields overlapped, avoids diplopia/confusion

Assess: overcome prism

Convergence/divergence

Question 6

Convergence Insufficiency

Answer 6

You read for a while and then things get blurry because your convergence ability is poor

Question 7

Divergence

Answer 7

See a far object, not completely lined up. Minimal misalignment of objects in the distance. Maybe it’s a problem with the tendons that hold the eye in place (sags a little)

Question 8

Vestibular Ocular Reflex

Answer 8

Maintains eyes on moving target

Assess: head shaking, pursuit at zero velocity

It compensates for your head moving. Notes position change of head and moves eyes in the opposite direction

Question 9

Estropia

Answer 9

Crossing inward

Tropia: manifest misalignment, it’s there all the time.

Question 10

Ocular Alignment Assessment

Answer 10

Have them focus on some object. Keep eyes right on the light switch or on that letter. Whenever he covers left eye, no movement. BUT when you cover the right eye, the left eye moves out, it’s crossed. (Because it’s not looking at the chart). You know the eye was in because it had to move out.

Method number 1 of measuring alignment

People who are born this way usually don’t have double vision

Question 11

Cover/Uncover Test

Answer 11

You’ll A see you only look at the eye that’s uncovered. Don’t see any movement of the uncovered eye. His eyes are straight at this moment, no tropia (manifest malignment).

This test ends with your hand up still. Don’t pay attention when you drop your hand

Allows brain to regain fusion

Question 12

Cross Cover Test

Answer 12

You see movement, the eye that is uncovered moves in. The way was out, it’s moving in to cover the target

Unmasks any latent misalignment. Doesn’t allow brain to regain function

Question 13

Difference between phoria and tropia

Answer 13

Phoria: a latent misalignment. Can control it. Big ones eventually might turn into tropia’s and can’t control

Tropia: Can’t control misalignment

Question 14

Measuring how big the misalignment is

Answer 14

Each rectangle is a stronger prism

if you hold it in the right direction, you can bend the light, make up for whatever he’s doing and movement goes away

Measured in diopter. Can measure the amount of misalignment with the prism

It’s quantifiable. Can follow things over time by making those measurements

Question 15

Right 3rd nerve Palsy

Answer 15

Ptosis

His eye doesn’t move down, it moves laterally

Doesn’t move down , up or in

Pupil will usually be dilated, it’s a dead giveaway

Question 16

Oculomotor Nerve

Answer 16

Parasympathetic: ciliary body/iris sphincter

Levator palpebrae

inf, sup, and med recti, inf. Oblique

Question 17

Origin of posterior communicating artery

Answer 17

Close to the CN III

Hits CN III first if you have an aneurysm

Question 18

Right 4th Nerve Palsy

Answer 18

Remember this: how does the superior oblique muscle attach to the eyeball?

This intorts and depresses the eye

If it isn’t working like it should, eye goes up and extorts

Eye will be extorted a little bit, ONLY problem when the eye is in adduction and depression. Don’t really see torsion, you see a lack of depression and adduction

MOST COMMON palsy from a head injury. Usually get better over a couple months

Question 19

6th Nerve Palsy

Answer 19

Lack of abduction of eye

You’d be estropic, his eye would be turned in a little bit

Not noticeable when you look toward the lesion

Question 20

Internuclear Ophthalmoplegia

Answer 20

Ipsilateral adduction deficit

Contralateral abduction deficit (nystagmus)

Can be caused by a very small lesion

• younger person: MS
• older person: lacunae infarct

Question 21

Gaze Palsy

Answer 21

When neither eye moves in a direction

Question 22

Parinaud’s Dorsal Midbrain Syndrome

Answer 22

Patient can’t look up

Pupils won’t cooperate either

It’s a vertical gaze palsy
Light/near dissociation (light reaction is absent but accomodation is present)
Lid retraction
Convergence-retraction nystagmus

Question 23

Miller Fisher Variant of Gullain Barre

Answer 23

Anti-GQ1b Ab

Ophthalmoplegia
Areflexia

Post-infectious (campylobacter)

Tends to target intermodal spaces on occulomotor cranial nerve

Question 24

Myasthenia Gravis

Answer 24

Ptosis
Ophthalmoplegia

Fatiguable ptosis and variable ptosis

problem with antibodies that bind to receptor sites
Ptosis and/or double vision
60-70% become generalized
30-50% develop myasthenic crisis
Respiratory distress due to muscle weakness
75% mortality rate prior to immunotherapy

Question 25

Nystagmus

Answer 25

A to-and-fro movement of the eyes

Prevents steady fixation of the eyes

Question 26

Downbeat Nystagmus

Answer 26

Anticonvulsants
Lithium
Anti-Yo Ab
Wernicke's 
Low Mg
Vit B12 deficiency 
Craniocervical jct
Vestibulocerebellum

Question 27

Normal Nystagmus?

Voluntary-party trick

Answer 27

Opsiclonus: have to worry about retinoblastoma (saccadomania). Need to rule it out