Visual Field Defects Flashcards
What is hemianopia?
Loss of one half of your visual field
What is homonymous hemianopia?
Loss of vision in the same half of both eyes.
Where is the lesion in someone with left homonymous hemianopia?
In the right optic tract
Where is the lesion in someone with right homonymous hemianopia?
In the left optic tract
What is bitemporal hemianopia?
Vision is missing in the outer half of both the right and left visual field
Where is the lesion in someone presenting with bitemporal hemianopia?
Optic chiasm
What is the optic chiasm?
Where the nasal fibres of each eye cross the midline to join the temporal fibres of the contralateral eye
If there is upper quadrant defect > lower quadrant defect in someone with bitemporal hemianopia, where is the compression?
Inferior chiasmal compression
What is inferior chiasmal compression usually due to in someone with bitemporal hemianopia?
Pituitary tumour
If there is inferior chiasmal compression in someone with bitemporal hemianopia, what defect presents?
Upper quadrant defect
If there is lower quadrant defect > upper quadrant defect in someone with bitemporal hemianopia, where is the compression?
Superior chiasmal compression
What is superior chiasmal compression usually due to in someone with bitemporal hemianopia?
Craniopharyngioma
What is a congruous defect?
A complete or symmetrical visual field loss
What is an incongruous defect?
Incomplete or asymmetric visual field loss
Where would the lesion be in someone presenting with homonymous hemianopia with incongruous defects?
Lesion of the optic tract