[13] Anterior Ischaemic Optic Neuropathy Flashcards
What is anterior ischaemic optic neuropathy?
A medical condition involving loss of vision caused by damage to the optic nerve as a result of insufficient blood supply
What are the two general types of anterior ischaemic optic neuropathy?
- Arteritic AION
- Non-arteritic AION
What is arteritic anterior ischaemic optic neuropathy?
Loss of vision as a result of temporal arteritis
What causes non-arteritic anterior ischaemic optic neuropathy?
Due to non-inflammatory disease of small blood vessels
What do these cards mostly relate to?
Non-arteritic anterior ischaemic optic neuropathy
Where are the cards on arteritic anterior ischaemic optic neuropathy?
In temporal arteritis
What is non-arteritic anterior ischaemic optic neuropathy?
An isolated white-matter stroke of the optic nerve
What are the risk factors for non-arteritic anterior ischaemic optic neuropathy?
- Predisposition due to type of optic disc
- Cardiovascular risks
- Nocturnal arterial hypotension
What type of optic disc predisposes to non-arteritic anterior ischaemic optic neuropathy?
‘Crowded’ optic disc
What is the optic disc?
The place where the axons from the retinal ganglion cells collect into the optic nerve
What must optic nerve penetrate?
The wall of the eye
How large is the hole in the eye for optic nerve?
Usually 20-30% larger than the nerve diameter
What is a crowded optic disc?
Where the optic nerve is nearly as large as the opening in the back of the eye
What are the cardiovascular risk factors for non-arteritic anterior ischaemic optic neuropathy?
- Diabetes
- Hypertension
- High cholesterol levels
What is nocturnal arterial hypotension?
When there is a marked fall in BP when falling asleep