Eye Movement Defects

Question 1

what is the first manifestation of a squint (eyes look in different directions)

Answer 1

diplopia (double vision)

Question 2

different types of double vision

Answer 2

horizontal
vertical
both

Question 3

how to diagnose a squint (tropia)

Answer 3

cover test

Question 4

describe how to carry out a cover test

Answer 4

glasses on
look at corneal reflection (slightly nasal- will be asymmetrical in a manifest squint)
cover one eye and watch the other eye for movement
if movement then there is a tropia

Question 5

what do you need to carry out a cover test?

Answer 5

pen torch
occluder
near (1/3m) and distant 6m targets

Question 6

four types of tropias

Answer 6

esotropia
exotropia
hypertropia
hypotropia

Question 7

define esotropia

Answer 7

outward movement of the eye (convergent)

Question 8

define exotropia

Answer 8

inward movement of the eye (divergent)

Question 9

define hypertropia

Answer 9

downward movement of the eye

Question 10

define hypertropia

Answer 10

upward movement of the eye

Question 11

what does ocular motility assess?

Answer 11

muscle pairs

Question 12

what do you need to test ocular motility?

Answer 12

pen torch
examine without glasses
cover 9 position

Question 13

what in a ocular motility test tells you there is a weak muscle?

Answer 13

there is visible sclera when looking in that direction

Question 14

three examples of eye movement defects

Answer 14

1. VIth nerve palsy
2. IVth nerve palsy
3. IIIrd nerve palsy

Question 15

describe VIth nerve palsy

Answer 15

lateral rectus cannot abduct fully so there is visible sclera left when looking outwards

Question 16

presentation of VIth nerve palsy

Answer 16

horizontal diplopia

Question 17

causes of VIth nerve palsy in over 50s

Answer 17

microvascular

Question 18

causes of VIth nerve palsy in under 50s

Answer 18

raised ICP
tumour
congenital

Question 19

where does the VIth CN run?

Answer 19

it rests of the petrous portion of the temporal bone therefore raised pressure can compress this

Question 20

describe IVth nerve palsy

Answer 20

superior oblique cannot depress eye so inferior oblique works unopposed (eye can drift up when looking ahead)

Question 21

presentation of IVth nerve palsy

Answer 21

hypertropia
vertical diplopia
head tilt

Question 22

causes of IVth nerve palsy

Answer 22

congenital decompensated
microvascular
tumour
bilateral in closed head trauma (shaking of brain in cranial cavity can stretch 4th nerve which is very thin)

Question 23

describe IIIrd nerve palsy

Answer 23

MR, IR, SR, IO, sphincter pupillae and levator palpebrae superioris are affected

Question 24

presentation of IIIrd nerve palsy

Answer 24

down and out
ptosis
dilated pupil
diplopia that is both horizontal and vertical (diagonal)
exotropia with hypotropia

Question 25

causes of IIIrd nerve palsy

Answer 25

expanding aneurysm in the brain
tumour
MS
congenital

Question 26

management of IIIrd nerve palsy

Answer 26

straight for scan

Question 27

how do you distinguish aneurysm from microvascular in IIIrd nerve palsy?

Answer 27

involvement of the pupil

Question 28

cause of internuclear ophthalmoplegia

Answer 28

eyes work together due to a connection between the nuclei of the medial longitudinal fasciculus
if affected there is inability to adduct
this can be affected by mass, MS (demyeliantion) or vascular