Visual field defects Flashcards
Visual field pathway
Visual field (L/R)
Retina (nasal/temporal)
Optic nerve
Optic chiasm
Optic tract
Lateral geniculate nucleus
Optic radiation (temporal/parietal lobe)
Occipital lobe
Lesion at macular
Ipsilateral central scotoma
Lesion at optic nerve
Ipsilateral monocular blindness
Lesion at optic chiasm
Bitemporal hemianopia
Lesion at optic tract
Contralateral homonymous hemianopia
Lesion at temporal lobe
Contralateral homonymous superior quadrantanopia
Lesion at parietal lobe
Contralateral homonymous inferior quadrantanopia
Lesion at occipital lobe
Contralateral homonymous hemianopia with macular sparing
(If superior vision is more affected, lesion is located inferior to calcarine sulcus and vice versa)
How to test for presence of macular sparing?
Move red target horizontally from non-seeing field into seeing field
If the red pin is noticed before it crosses the midline, macular sparing is present
Types of monocular visual field defects
- Central scotoma
- Inferior altitudinal defect
- Arcuate defect arising from blind spot
Cause of central scotoma
Optic neuritis (affects macular)
ARMD
Maculopathy
Cause of inferior altitudinal defect
Ischemic optic neuropathy
Cause of arcuate defect arising from blind spot
Glaucoma
Types of binocular visual field defects
- Monocular visual loss in both e yes
- Bitemporal hemianopia
- Homonymous hemianopia
- Homonymous superior quadrantanopia
- Homonymous inferior quadrantanopia
- Homonymous hemianopia with macular sparing
Cause of monocular visual loss in both eyes
Bilateral optic neuropathies or retinopathies
Cause of bitemporal hemianopia
Optic chiasm
- Pituitary macroadenoma
- Craniopharyngioma
- Meningioma
Cause of homonymous hemianopia
Contralateral retrochiasmal visual pathway
Cause of homonymous superior quadrantanopia
Contralateral temporal lobe
Cause of homonymous inferior quadrantanopia
Contralateral parietal lobe
Cause of homonymous hemianopia with macular sparing
PCA stroke (Occipital lobe)
- Macular sparing due to dual supply of blood to macula by PCA and MCA
Symptoms of lesion at optic chiasm
Chiasmal syndrome
- Bitemporal hemianopia* (hallmark sx)
- Signs of raised ICP
- Headaches
- Acromegaly
- Galactorrhoea
- Gynaecomastia
- Visual hallucinations
Signs of chiasmal compression seen on fundoscopy
Bowtie optic atrophy
bilateral disc swelling + clinical signs of RAISED ICP = papilloedema
Clinical testing of visual field
Central VF
1. Amsler chart
2. Confrontation
- Count fingers
- Hand movement
- Light projection
Peripheral VF
1. Confrontation
2. Red dot perimetry
Investigations for VF
Bjerrum screen
Goldmann perimetry
Humphrey perimetry
what type of nystagmus is associated with bitemporal hemianopia?
see-saw nystagmus
