VF defects, double vision and optic disc swelling

Question 1

Lesion anterior to the chiasm =

Answer 1

Unilateral defect

Question 2

Lesion posterior to the chiasm =

Answer 2

Contralateral homonymous defect

Question 3

Chiasmal lesion =

Answer 3

Bitemporal hemianopia (generally)

Question 4

Features of homonymous hemianopia:

Answer 4

Bilateral so post-chasm
Same side
More congruous = closer to occipital cortex
Commonly caused by stroke

Question 5

Lesion of inferior optic radiations as they pass through the parietal lobes causes…

Answer 5

Quadrantopia

e.g. right homonymous inferior quadrantopia is from a lesion of the upper optic radiation in the parietal lobe

Question 6

Features of bitemporal hemianopia:

Answer 6

Lesion at the chasm
Initially incomplete and asymmetric and progresses
Commonly neoplastic

Question 7

What VF defect does a pituitary tumour often cause?

Answer 7

Bitemporal superior quandrantopia (often asymmetric and respect the vertical midline but not horizontal)
Bitemporal hemianopia with tumour progression

Question 8

What is the cause and effect of central VFD?

Answer 8

Caused by macula degeneration (commonest form is age related but could be nutritional, toxic etc)
Effect is decrease in VA and colour vision

Question 9

Associated symptoms of VFD:

Answer 9

Headache and neurological symptoms
Photopsia
Pain
CV problems
Pituitary problems

Question 10

Causes of diplopia:

Answer 10

CN III, IV, VI palsies (diabetes and hypertension)
Globe displacement
Decompensation of latent squint
Myasthenia graves
Thyroid eye disease

Question 11

What does abnormal head posture imply?

Answer 11

Recent onset diplopia

Question 12

What is strabismus?

Answer 12

Misalignment of one of the eyes from fixating straight ahead

Question 13

What is monocular diplopia?

Answer 13

Double vision which persist when one eye is covered

‘Ghosting’

Question 14

What causes monocular diplopia?

Answer 14

Corneal abnormalities e.g. scarring
Uncorrected refractive error (uneven light splitting)
Cataract

Question 15

What is binocular diplopia?

Answer 15

Both eyes misaligned in straight ahead/various positions of gaze
May be due to motor nerves or extra ocular muscles

Question 16

Tests in diplopia:

Answer 16

VA
Abnormal head position
Refraction
Motility
Cover test

Question 17

What does posterior communicating artery aneurysm cause?

Answer 17

Painful unilateral CN III palsy

Question 18

Character of diabetes/hypertension driven CN III palsy?

Answer 18

Spares the pupil

Question 19

Character of CN III palsy diplopia:

Answer 19

Eye in a down and out position +/- a dilated pupil
(exo hypo deviation)
Because SO and LR are now unopposed

Question 20

Character of CN IV palsy diplopia:

Answer 20

Cannot carry out intorsion to bring eye in and down towards nose
Abnormal head position - tilt away from side of lesion
Eye will deviate up as it approaches the nose
Unilateral or bilateral
CN IV supplies superior oblique

Question 21

Treatment of CN IV palsy:

Answer 21

In children treat any amblyopia and correct refractive error
Prisms
Surgery to improve diplopia and for cosmetic reasons

Question 22

Character of CN VI palsy diplopia:

Answer 22

Failure in abduction of the eye
Horizontal diplopia worse when looking to affected side
AHP - head turn to same side
Eso deviation on cover test (nasal direction)
CN VI supplies lateral rectus

Question 23

Cause of CN VI palsy:

Answer 23

Hypertension/diabetes, neoplasm, trauma, infection
MS
Transient in neonates
Benign causes 1-3 weeks after viral infection

Question 24

Tests with optic disc swelling:

Answer 24

CN II
VA and VF
Colour
Pupil reactions

Question 25

Unilateral causes of optic disc swelling:

Answer 25

CRVO
non-AION and AION (GCA)
Papillitis - inflammation of the optic nerve head
Neuroretinitis - inflammation of optic nerve and peripapillary retina

Question 26

Bilateral causes of optic disc swelling:

Answer 26

Intracranial mass raising ICP (papilloedema)
Malignant hypertension
Optic disc druse (calcifications) can cause pseudopapilloedema but usually asymptomatic

Question 27

Exams for optic disc swelling:

Answer 27

CNs
Rule out systemic hypertension, raised ICP and GCA
Bilateral funds exam
Test for proptosis

Question 28

What is proptosis?

Answer 28

Forward displacement of the eye anteriorly