Visual loss Flashcards
What are the causes of sudden visual loss?
Vascular (central retinal artery/ vein occlusion) Vitreous haemorrhage Retinal detachment ARMD - wet Closed angle glaucoma Optic neuritis Stroke
What is the arterial supply to the eye?
All arises from the ophthalmic artery
Posterior ciliary artery supplies the optic nerve head
Central retinal artery supplies the retina
What are the symptoms of central retinal artery occlusion (CRAO)?
Sudden visual loss
Painless
What are the signs of CRAO?
RAPD
Pale, edematous retina
Thread like retinal vessels
Cannot see top letter on snellen chart
What are the common causes for CRAO?
Carotid artery disease
Emboli from heart due to vegetations on heart valve
What will branch retinal artery occlusion cause?
A section of the retina will be pale and ischaemic
What are the symptoms of amaurosis fugax?
Transient painless visual loss
“Like a curtain coming down”
Lasts 5 mons
What should be done if someone presents with a history of amaurosis fugax?
Urgent referral to stroke clinic as it can be a pre-warning to a stroke
What is central retinal vein occlusion (CRVO) associated with?
Endothelial damage e.g. diabetes
Abnormal blood flow e.g. hypertension
Hypercoagulable state e.g. cancer
What are the symptoms of CRVO?
Sudden visual loss if there is ischaemia
What are the signs of CRVO?
Retinal haemorrhages
Dilated tortuous vessel
Disc swelling and macular swelling
Cotton wool spots (small infarcts of the nerve fiber layer)
What can cause ischaemic optic neuropathy?
Occluded posterior ciliary artery
Giant cell arteritis
What causes ION in GCA?
Posterior ciliary arteries become inflamed with multinucleated giant cells causing a gross thickening of artery wall resulting in visual loss due to ischaemia of the optic nerve head
What are the symptoms of ION?
Sudden severe visual loss
Irreversible blindness
What is the sign of ION?
Swollen optic nerve
Pale disc
What are the symptoms of GCA?
Temporal headache Jaw claudication Scalp tenderness Amaurosis fugax Malaise
What is vitreous haemorrhage?
Bleeding from abnormal neovascularization bleeds into vitreous causing floaters
When will neovascularization occur in the retina?
Retinal ischaemia in diabetes or retinal vein occlusion sends out VEGF resulting in abnormal, fragile blood vessels to form which are susceptible to bleeding
What are the symptoms of vitreous haemorrhage?
Loss of vision
Floaters
What are the signs of vitreous haemorrhage?
Loss of red reflex
Haemorrhage on fundoscopy
What are the symptoms of retinal detachment?
Painless loss of vision
Sudden onset of flashes/ floaters
What are the signs of retinal detachment?
RAPD
Tear on ophthalmoscopy
What is wet ARMD?
New blood vessels grow under the retina resulting in leakage causing a build up of fluid/ blood and eventual scarring
What are the symptoms of wet ARMD?
Rapid central vision loss
Distortion (metamorphopsia)
What are the signs of wet ARMD?
Pale macula
Exudates at the periphery of macula
Small haemorrhages