What are Charles Bonnet illusions?
Moths or other complicated illusions that occur in people with existing poor vision
Does the retina have collateral supply?
No
What causes spots and flickers in vision?
Separation of vitreous from the retina
- Occurs normally in life
- Can follow trauma
How does giant cell arteritis present?
Headache
Scalp tenderness
Polymyalgia rheumatica
Jaw claudication
What causes whizzes and zigzags?
Migraine
Is the red reflex present in the embolism?
Yes
How do retinal detachments arise?
An existing tear in the retina is infiltrated with vitreous
What is the common cause of anterior ischaemic optic neuropathy?
Giant cell arteritis
Why must spots and flickers be investigated?
They can indicate retinal tears
What is the commonest cause of central retinal artery occlusion?
Atheroma
What causes flashes?
Vitreous mobility - uniocular
Retinal ischaemia - uniocular
Cortical infarction - binocular (Posterior cerebral artery)
Where is the commonest site of embolise?
Bification of the common carotid
What do you see on the retina with central retinal artery occlusion?
Cherry red spot in contrast to opaque retina
How do you Ix giant cell arteritis?
ESR
CRP
Superficial temporal artery biopsy
How does the pupil behaviour with embolism?
No direct response
There will be consenual response
How does retinal artery embolism present?
Sudden loss of vision
Painless
What are common causes of transient vision loss?
TIA - particularly platelet emboli from the internal carotid
Vitreous haemorrhage
Is oxygen therapy effective in embolism?
No
How long can the retina last without blood supply?
A few hours
What are the acute management goals in embolism?
Sudden lowering of intraocular pressure to cause a transient vasodilation so the embolise is dislodged
What is anterior arteritic ischaemic optic neuropathy?
Any ischaemia in the posterior circulation of the globe that supplies the optic disc. This results in optic neuropathy (damage to the optic nerve) which causes vision loss associated with optic disc swelling
