Sudden vision loss Flashcards
What are the causes of sudden vision loss?
retinal artery/vein occlusion virteous haemorrhage retinal detachment wet age related macular degeneration - haemorrhage of abnormal vessels haemorrhages from normal vessels - e.g. bridging a retinal tear optic neuritis closed angle glaucoma stroke
How does a central retinal artery occlusion present?
painless sudden vision loss
What are the signs of a CRAO?
RAPD PALE odematous retina thread like retinal vessels swollen retinal ganglion cells cherry red spot at the fovea
What does the central retinal artery supply?
inner 1/3rd of the retina
What can cause CRAO?
carotid artery disease
emboli from the heart
What are the two types of CRAO?
branch retinal artery occlusion
amaurosis fugax
Describe a branch retinal artery occlusion?
only one half of the retina becomes pale
Describe an amaurosis fugax?
transient visual loss, like a curtain coming down
resolves after 5 mins
nothing abnormal on examination
What must you do with a patient with CRAO?
urgently refer them to the stroke clinic
What is a central retinal vein occlusion associated with?
Virchows triad
What is the presentation of a CRVO?
sudden vision loss
rubeotic eye - vessels growing on the iris
What are the signs of CRVO?
dark fundoscopy photo with cotton wool spots
retinal haemorrhages
dilated tortuous veins
disc swelling
What are the characteristics of a branch CRVO?
loss of just part of a field of view - patient often not aware of it
may be painless and asymptomatic
What is ischeamic optic neuropathy?
oclusion of the optic nerve head circulation - posterior cilliary artery
What can cause ischeamic optic neuropathy?
giant cell arteritis
What is the presentation of ischeamic optic neuropathy?
sudden vision loss
irreversible blindness
What signs can be see on fundoscopy in an ischeamic optic neuropathy?
swollen optic disc
What is a vitreous haemorrhage?
bleeding occuring from abnormal vessels (diabetic retinopathy or retinal vein occlusion causing new vessels to form) or bleeding can occur from normal vessels but theres been a tear - bridging retinal tear
What is the presentation of a vitreous haemorrhage?
vision loss
floaters
What are the signs of a vitreous haemorrhage?
loss of red reflex due to an unclear retina
haemorrhages
What is the pathophysiology behind a retinal detachment?
the vitreous fluid starts to collapse in on itself as we age, as it does this it tears the retina
What is the presentation of a retinal detachment?
painless loss of vision
sudden onset floaters and flashing lights (due to mechanical seperation of sensory retina from pigment epithelium)
What are the signs of a retinal detachment?
RAPD
tear on ophthalmoscopy
