Disease Profiles: Neuro-Opthalmic Disease

Question 1

List 4 causes of visual field defects

Answer 1

Vascular disease - CVA

Space occupying lesion (SOL) e.g. pituitary tumour

Demyelination (MS)

Trauma - including surgical

Question 2

What is sudden onset diplopia?

Answer 2

Patient has changed from having binocular single vision, seeing one image only, to a sudden onset manifest squint and diplopia (double vision)

Question 3

Describe the clinical presentation of optic neuritis

Answer 3

Progressive unilateral visual loss

Pain behind eye, especially on movement

Colour desaturation

Central scotoma

Question 4

Horizontal double vision with esotropia/exotropia on cover test suggests a problem with which ocular muscles?

Answer 4

Medial or lateral rectus

Question 5

Describe the clinical presentation of a CN IV nerve palsy

Answer 5

Typically results in vertical diplopia when looking inferiorly, due to loss of the superior oblique’s action of pulling the eye downwards

Affected eye turned upward in primary position

Question 6

What pathology would result in a bitemporal field defect?

Answer 6

Optic chiasm defect - pituitary tumour, craniopharyngioma, meningioma

Question 7

Describe the findings on fundoscopy associated with optic atrophy

Answer 7

Pale optic disc

Question 8

What investigation us used to detect a manifest squint (topia)?

Answer 8

Cover test

Question 9

Name 3 causes of papilloedema

Answer 9

Space-occupying lesion

Problems with cerebral blood flow (e.g. malignant hypertension)

Problems with CSF (obstruction to circulation, overproduction, inadequate absorption)

Question 10

What causes sudden onset diplopia?

Answer 10

New weakness of extra-ocular muscles

Question 11

What would be the most likely cause of a painful CN III palsy?

Answer 11

Aneurysm

Question 12

What pathology would result in a contralateral homonymous hemianopia (macula not spared)?

Answer 12

Optic tract defect - tumours, demyelination, vascular anomalies

Question 13

Which cranial nerve supplies all extaocular muscles except superior oblique and lateral rectus?

Answer 13

CN III

Question 14

What is non-arteric ischaemic optic neuropathy?

Answer 14

ION due to non-inflammatory disease of small blood vessels - vascular risk factors

Question 15

What is the most common cause of internuclear opthalmoplegia in a younger patient?

Answer 15

MS

Question 16

Name the cranial nerve which supplies the superior oblique

Answer 16

CN IV

Question 17

Describe the findings on fundoscopy associated with ischaemic optic neuropathy

Answer 17

Pale, swollen disc

Question 18

Name a common cause of bilateral optic disc swelling in young females

Answer 18

Swelling of the optic nerve due to increased intracranial pressure

Question 19

Name a complication of chronic papilloedema

Answer 19

Chronic papilloedema can cause axon damage leading to optic atrophy → loss of visual function occurs and blindness may result

Question 20

What pathology would result in a contralateral homonymous quadrantanopia (macula not spared)?

Answer 20

Optic radiation defect - tumours, demyelination, vascular anomalies

Question 21

Define ischaemic optic neuropathy

Answer 21

Occlusion of the posterior ciliary arteries, resulting in infarction of the optic nerve head

Question 22

What causes internuclear opthalmoplegia?

Answer 22

Injury/dysfunction in the medial longitudinal fasciculus (tract which acts as the central connection for the oculomotor nerve, trochlear nerve, and oculomotor nerve)

Question 23

Describe the clinical presentation of a CN VI nerve palsy

Answer 23

Results in unopposed adduction of the eye (by the medial rectus muscle), resulting in a convergent squint or esotropia (eye turns inwards)

Patients typically present with horizontal diplopia which is worsened when they attempt to look towards the affected side

Question 24

Name 4 causes of a CN VI nerve palsy

Answer 24

Microvascular

Raised intracranial pressure

Tumour

Congenital

Question 25

What autoimmune disease can cause ischaemic optic neuropathy

Answer 25

Temporal (giant cell) arteritis - posterior ciliary arteries become affected and the wall becomes so inflamed/thickened that lumen becomes occluded

Question 26

What pathology would cause unilateral visual loss?

Answer 26

Defect to the optic nerve - ishcaemic optic neuropathy, optic neuritis (commonly MS), tumours (meningioma, glioma, haemangioma)

Question 27

What causes optic atrophy?

Answer 27

End stage that arises from damage to the optic nerve of any cause

Question 28

Describe the findings on fundoscopy associated with papilloedema

Answer 28

Disc swelling (blurring)

Question 29

How can CN III nerve palsy cause miosis?

Answer 29

Loss of parasympathetic fibres responsible for innervating to the sphincter pupillae muscle

Question 30

Describe the prognosis of optic neuritis

Answer 30

Gradual recovery over weeks to months

Question 31

How can CN III nerve palsy cause ptosis?

Answer 31

Due to a lack of innervation to levator palpebrae superioris

Question 32

How might patients with IV palsies compensate for diplopia with variable head positioning?

Answer 32

Chin-down head posture is seen in bilateral CN IV palsy and contralateral head tilt is typically seen in unilateral CN IV palsy (common in children)

Question 33

Describe the clinical presentation of a CN III nerve palsy

Answer 33

'Down and out' appearance of the affected eye due to unopposed action of both the lateral rectus and superior oblique muscles, which pull the eye inferolaterally Can also cause ptosis and miosis

Question 34

Define papilloedema

Answer 34

Swelling of the optic nerve due to increased intracranial pressure

Question 35

What pathology would result in a contralateral homonymous hemianopia with macular sparing?

Answer 35

Occipital cortex defect - vascular disease (CVA), demyelination

Question 36

Vertical double vision with hypertropia/hypotropia on cover test suggests a problem with which ocular muscles?

Answer 36

Superior oblique, superior rectus, inferior rectus, inferior oblique

Question 37

Describe the pathophysiology of papilloedema

Answer 37

When intracranial pressure rises, the increased pressure is transmitted to the subarachnoid space and then onto the optic nerve This causes interruption of axoplasmic flow and venous congestion → swollen discs

Question 38

Describe the clinical presentation of papilloedema

Answer 38

Headache Enlarged blind spot, blurring of vision, visual obscurations and loss of vision N+V, especially if ICP rise is acute

Question 39

List 5 causes of a CN III nerve palsy

Answer 39

Microvascular Tumour **Aneurysm** MS Congenital

Question 40

What is the most common cause of internuclear opthalmoplegia in an older patient?

Answer 40

Generally have a vascular aetiology (stroke)

Question 41

Name the cranial nerve which supplies the lateral rectus muscle

Answer 41

CN VI

Question 42

Describe the clinical presentation of ischaemic optic neuropathy

Answer 42

Sudden visual loss Usually painless If associated with GCA - headache, scalp tenderness, enlarged temporal arteries

Question 43

List 4 causes of a CN IV nerve palsy

Answer 43

**Congenital decompensated** Microvascular Tumour Blunt head **trauma** can result in bilateral CN IV palsy

Question 44

Describe the clinical presentation of internuclear opthalmoplegia

Answer 44

Impairment of adduction

Question 45

Define internuclear opthalmoplegia

Answer 45

Disorder of conjugate lateral gaze in which the affected eye shows impairment of adduction

Question 46

Define optic atrophy

Answer 46

Death of the retinal ganglion cell axons that comprise the optic nerve