Visual loss and blindness Flashcards
Amaurosis fugax
Painless, transient monocular vision loss
Transient CRAO
Lasts 5 mins, full recovery
May be sign of a stroke
Emmetropia
Normal
Hypermetropia
Long sighted
Myopia
Short sighted
Presbyopia
Deterioration with age, less compliant lens
How to correct hypermetropia
Convex lens (+)
How to correct myopia
Concave lens (-)
ARMD vision
Central vision lost
Blood to inner 2/3 retina
Central retinal artery
Blood to outer 2/3 retina and optic nerve head
Posterior ciliary artery
Symptoms and signs of CRAO
Sudden profound LOV
Painless
RAPD
Pale oedematous retina, cherry red spot
Causes of CRAO
Carotid artery disease
Emboli
Treatment of CRAO
Ocular massage (within 24 hours) Induce hypercapnia (breathe into paper bag) IV acetazolamide bolus Surgically decompress anterior chamber Carotid doppler Assess risk factors
Management of amaurosis fugax
Refer to TIA clinic
Aspirin
Causes of CRVO
Atherosclerosis
HT
Hyperviscosity
Raised IOP
Symptoms and signs of CRVO
Sudden visual loss
Retinal haemorrhages, dilated tortous veins, disc and macular swelling
Cotton wool spots
Treatment of CRVO
Anti-vEGF
Ischaemic optic neuropathy
Occlusion of optic nerve head
Posterior ciliary arteries occluded (outer 1/3 retina)
Ischaemia = optic nerve dysfunction