Visual Field Defect

Question 1

what is the visual processing of the left field?

Answer 1

left nasal - crosses optic chiasm - processed right optic tract
right temporal - processed right optic tract

Question 2

what is the visual processing of the right field?

Answer 2

right nasal - crosses optic chiasm - processed left optic tract
left temporal - processed left optic tract

Question 3

what are the causes of visual field defects?

Answer 3

• Vascular defect
• Tumours
• Trauma
• Demyelination
• Inflammation
• Congenital abnormalities
• Ischemia
• Haemorrhage
• Nutritional abnormalities
• Toxicity

Question 4

what is the normal visual pathway?

Answer 4

• Optic pathway = optic nerve – chiasm – optic tracts – optic radiations – cortex

Question 5

if the temporal region is affected in the visual pathway, where is the defect?

Answer 5

TOP

Question 6

what is the pathophysiology of visual field defects?

Answer 6

• Result from disruption of nerve conduction

* Visual disruption depends on which part of pathway is disrupted

Question 7

what are the different types of visual field defects?

Answer 7

Ipsilateral monocular visual loss
Bitemporal hemianopia
Contralateral homonymous heminopia
Right superior homonymus quadrantopia
Right homonymous inferior quadrantopia
Right homonymus heminopia with macular sparing

Question 8

what is ipsilateral monocular visual loss?

Answer 8

vision in one whole eye lost

Question 9

what is bitemporal heminanopia?

Answer 9

vision in both temporal regions lost (outer half of each eye)

Question 10

what is contralateral homonymous hemianopia?

Answer 10

either left or right visual loss in both eyes

Question 11

what is right superior homonymous quadrantopia?

Answer 11

loss of vision in top left visual field in both eyes

Question 12

what is right homonymous inferior quadrantopia?

Answer 12

loss of vision in bottom left of each eye

Question 13

what is right homonymous heminopia with macular sparing?

Answer 13

either left or right visual loss in both eyes but macula spared

Question 14

where is the site of lesion causing Ipsilateral monocular visual loss?

Answer 14

Optic nerve

Question 15

where is the site of lesion causing Bitemporal hemianopia?

Answer 15

optic chiasm

Question 16

where is the site of lesion causing Contralateral homonymous heminopia?

Answer 16

optic tract

Question 17

where is the site of lesion causing Right superior homonymus quadrantopia?

Answer 17

Temporal lower optic radiation

Question 18

where is the site of lesion causing Parietal upper optic radiation?

Answer 18

Parietal upper optic radiation

Question 19

where is the site of lesion causing Right homonymus heminopia with macular sparing?

Answer 19

Optic visual cortex

Question 20

what are the causes of Ipsilateral monocular visual loss?

Answer 20

Optic neuritis

CRAO

Question 21

what are the causes of Bitemporal hemianopia?

Answer 21

Pituitary adenoma
Craniopharyngioma
Menginoma

Question 22

what are the causes of Contralateral homonymous heminopia?

Answer 22

Middle cerebral artery occlusion
Tumours
Demyelination

Question 23

what are the causes of Right superior homonymus quadrantopia?

Answer 23

MCA occlusion, temporal lobe tumour (left)

Question 24

what are the causes of Right homonymus inferior quadrantopia?

Answer 24

Right homonymus inferior quadrantopia

Question 25

what are the causes of Right homonymus heminopia with macular sparing?

Answer 25

PCA occlusion (left)
Vascular disease
Demyelination

Question 26

how are visual field defects diagnosed?

Answer 26

• Visual field testing, blood tests, CT scan

Question 27

what is the management of visual field defects?

Answer 27

• Depends on cause
• CVS – management of conditions/risk, investigation of source of embolus
• Intracranial space lesion removed