Visual Field Defects

Question 1

How are visual field defects classified?

Answer 1

Based on the area of visual loss, not the site of the lesion

Question 2

What is monocular blindness?

Answer 2

Visual loss of one eye

Question 3

What causes monocular blindness?

Answer 3

Lesion of ipsilateral optic nerve

Question 4

What are some examples of optic nerve lesions?

Answer 4

Retinoblastoma or optic nerve glioma in children

Optic sheath meningioma in middle-aged people

Question 5

What is bitemporal hemi-anopia?

Answer 5

Visual loss of temporal fields in both eyes

Question 6

What causes bitemporal hemi-anopia?

Answer 6

Lesion of optic chiasm

Question 7

What are some examples of lesions of the optic chiasm?

Answer 7

Pituitary gland tumour

Anterior communicating artery aneurysm

Question 8

What is homonomous hemi-anopia?

Answer 8

Visual loss of nasal field in one eye and temporal field in the other eye

Question 9

What causes homonomous hemi-anopia?

Answer 9

Lesion of contralateral optic tract

Question 10

What are some examples of lesions of the optic tract?

Answer 10

Stroke

Neoplasia

Trauma

Question 11

What is quadrantanopia?

Answer 11

Visual loss of a quarter of the visual field in each eye

Question 12

Wha causes quadrantanopia?

Answer 12

Lesion of contralateral optic radiation

Question 13

What is macular sparing visual loss?

Answer 13

Visual loss of all the visual field except central vision

Question 14

What causes macular sparing visual loss?

Answer 14

Stroke involving posterior cerebral artery
Loss of blood supply to most of occipital lobe, apart from occipital pole which is supplied by the middle cerebral artery
The occipital pole represents the macula