Squints/Visual Acuity

Question 1

what is strabismus

Answer 1

malalignment of the eyes (squint)

Question 2

what is ambylopia

Answer 2

lazy eye

Question 3

what is a tropia

Answer 3

malalignment which is always there

Question 4

what is a phoria

Answer 4

malalignment which only occurs some of the time

Question 5

what is esotropia

Answer 5

convergent stabismus

quint where one or both eyes turn inwards

on cover test when the good eye is covered the other eye moves back out to assume a normal position

Question 6

what is a extropia

Answer 6

divergent strabismus

outward deviation of an eye

on cover test when you cover the normal eye the bad eye will move back inwards

Question 7

what do eco/esotropias do to vision

Answer 7

cause horizontal double vision

Question 8

what is a hypertrophia

Answer 8

one eye is deviated up the way

when you cover the good eye the bad eye moves down

Question 9

what is a hypotropia

Answer 9

one eye is deviated down the way

when you cover good eye the other eye moves up

Question 10

what do hyper and hypotropias do to vision

Answer 10

cause vertical double vision

Question 11

what eye movements should you do to check for tropias

Answer 11

get patient to look left, right and up into each corner then down into each corner

mark on diagram
100% - normal movement
0% - no movement

Question 12

when would you do a cover test

Answer 12

to show small tropias which aren’t visible to the eye

Question 13

on cover test the eye moves out- what is the deformity

Answer 13

esotropia

must have been in isotropic position before and is now moving out to a normal position bc it has to work harder with the good eye covered

Question 14

on cover test the eye moves in - what is the deformity

Answer 14

exotropia

must have been exotropic position to start with and is now moved in to a normal position

Question 15

causes of tropias

Answer 15

3rd nerve palsy
4th nerve palsy
6th nerve palsy
internuclear ophthalmoplegia

Question 16

how does a 3rd nerve palsy present

Answer 16

eye is in ‘down and out’ position

superior oblique and lateral rectus are still working

eyelid droops due to lack of leaver palpibrae superiors innervation

no/slow pupillary light reflex

Question 17

common causes of 3rd nerve palsy

Answer 17

microvascular 
tumour 
aneurysm 
MS 
congenital

Question 18

what type of aneurysm most commonly causes a third nerve palsy

Answer 18

Posterior communicating artery aneurysm

Question 19

how does a 4th nerve palsy present

Answer 19

paralysis of superior oblique (trochlear nerve palsy)

eye cannot move inferiomedially

therefore double vision occurs when looking down

head tilt is often seen to correct the double vision

Question 20

causes of 4th nerve palsy

Answer 20

congenital - most common
microvascular
tumour
trauma

Question 21

how does a 6th nerve palsy present

Answer 21

esotropia - paralysis of lateral rectus means eye turns inwards

Question 22

cause of 6th nerve palsy

Answer 22

microvascular causes
raised ICP (compressing CNVI onto petrous tip of temporal bone)
tumour
congenital

Question 23

what is internuclear opthalmoplegia

Answer 23

lesion in the longtidutinal fascicles (which is responsible to adducting one eye when the other abducts and vis versa)

most commonly caused by MS

Question 24

how does internuclear ophthalmoplegia present

Answer 24

one eye cannot abduct and the other eye has nystagmus