Visual Field Defects

Question 1

Name the following visual field defect and corresponding area of lesion with possible causes.

Answer 1

Monocular visual loss.

Lesion at the ipsilateral optic nerve or retina

i.e.

• central retinal artery occlusion: pale, milky fundus with thread arteries, +/- cherry macula, caused by AF (irregular pulse) or carotid stenosis (bruit) or GCA, OR branch if part of one eye vision affected (opposite field loss to quadrant affected)
• central retinal vein occlusion: +++ flame haemorrhages radiating from swollen disc, cotton wool spots, hypertensive/diabetic changes in branch occlusion, caused by hypertension, diabetes, hyperviscosity - myeloma, WM or glaucoma
• retinal detachment (preceding light flashes, large area of abnormal retina on fundoscopy), optic neuritis (painful visual loss, brightly pale optic disc, disc swelling)
• acute angle closure glaucoma (red, painful eye) or chronic glaucoma
• optic atrophy (RAPD, disc pallor)

Question 2

Name the following visual field defect and corresponding area of lesion with possible causes and associated features on exam.

Answer 2

Bitemporal hemianopia

Lesion at the optic chiasm

Pituitary tumour
Craniopharyngioma

May have raised ICP features, hormonal imbalances (GH def - delayed growth/puberty, gonaotrophin def - delayed puberty, TSH def - hypothyroid, ACTH def - addisons symptoms, ADH def - polydipsia/polyuria, depression/memory issues

Question 3

Name the following visual field defect and corresponding area of lesion with possible causes and associated features on exam.

Answer 3

Homonymous hemianopia without macular sparing.

Lesion at the contralateral optic tract i.e. middle cerebral artery occlusion (stem), tumour in frontal/temporal lobe causing compression, large aneurysm - rare presentation (associated features i.e. ADPCKD, smoking, Ehler’s Danlos - doughy skin, scarring from previous skin tears, hypermobile joints, ask about previous dislocations)

(PACS: 2/3 of hemiplegia, dysphagia, dyspraxia, neglect)

Question 4

Name the following visual field defect and corresponding area of lesion with possible causes and associated features on exam.

Answer 4

Homonymous inferior quadrantopia without macular sparing

Contralateral parietal (upper) optic radiation

Parietal lobe tumour, MCA occlusion (superior branch), large aneurysm - rare presentation (associated features i.e. ADPCKD, smoking, Ehler’s Danlos - doughy skin, scarring from previous skin tears, hypermobile joints, ask about previous dislocations)

(Features of PACS - 2/3 of hemiplegia, dysphagia, dyspraxia, neglect)

Question 5

Name the following visual field defect and corresponding area of lesion with possible causes and associated features on exam.

Answer 5

Homonymous superior quadrantopia

Contralateral temporal (lower) optic radiation lesion

Temporal lobe tumour, MCA occlusion (inferior branch), large aneurysm -rare presentation (associated features i.e. ADPCKD, smoking, Ehler’s Danlos - doughy skin, scarring from previous skin tears, hypermobile joints, ask about previous dislocations)

(Features of PACS - 2/3 of hemiplegia, dysphagia, dyspraxia, neglect)

Question 6

Name the following visual field defect and corresponding area of lesion with possible causes and associated features on exam.

Answer 6

Homonymous hemianopia with macular sparing

Contralateral occipital visual cortex (macular spared due to its supply via the mca)

Posterior cerebral artery occlusion,
- other features could be gaze palsy, bilateral sensory/motor loss, cerebellar syndrome, cranial nerve palsy with contralateral motor/sensory deficit) NB: only need one to diagnose POCS as per Bamford classification.
- occipital lobe tumour