Vascular Causes of Sudden Visual Loss Flashcards
what is the major blood supply to the eye
various branches of the ophthalmic artery
what are the 2 different vascular aetiologies of sudden visual loss
occlusion or haemorrhage
what can be occluded to result in sudden visual loss
occlusion of retinal artery or vein, or occlusion of optic nerve circulation
what can haemorrhage come from, resulting in sudden visual loss
haemorrhage from abnormal blood vessels or from normal blood vessels
what symptoms are associated with central retinal artery occlusion(CRAO)
sudden visual loss, painless
what signs are associated with central retinal artery occlusion(CRAO)
RAPD(relative afferent pupil defect), pale oedematous retina and thread-like retinal vessels
what are the causes of CRAO
carotid artery disease, emboli from the heart(unusual)
what are 2 other variants of retinal artery occlusion, other than CRAO
branch retinal artery occlusion, Amaurosis fugax(aka transient CRAO)
what symptoms and signs are associated with amaurosis fugax(transient CRAO)
transient painless visual loss, ‘like a curtain coming down’, lasts ~5mins with full recovery
usually no signs
(refer to stroke clinic)
what factors are associated with the formation of a central retinal vein occlusion
endothelial damage(ag diabetes), hypercoagulability(eg cancer), abnormal blood flow(eg hypertension)
what signs symptoms are associated with central/branch retinal vein occlusion
symptoms = sudden visual loss signs = retinal haemorrhages, dilated tortuous veins, disc and macular swelling,
what is occluded in optic nerve head circulation occlusion and what does this lead to
posterior ciliary arteries become occluded, results in infarction of optic nerve head
what signs and symptoms are seen in ischaemic optic neuropathy
symptoms = sudden visual loss, usually painless signs = pale and swollen optic nerve
what is optic nerve head occlusion also called
ischaemic optic neuropathy(ION)
what is an inflammatory condition that can cause ischaemic optic neuropathy(ION)
temporal(giant cell) arteritis
describe how the posterior ciliary arteries are affected in temporal arteritis
wall becomes so inflamed and thickened that lumen is occluded
what signs are seen in temporal(giant cell) arteritis
headache, scalp tenderness, enlarged temporal artery
can be sight and life threatening
describe how bleeding can occur from abnormal blood vessels causing vitreous haemorrhage
retinal ischaemia in diabetes or retinal vein occlusion causes abnormal, fragile new blood vessel formation
give an example of how bleeding can occur from abnormal blood vessels causing vitreous haemorrhage
when bridging a retinal tear
what are the signs and symptoms of a vitreous haemorrhage
signs = loss of red reflex, may see haemorrhage on fundoscopy symptoms = loss of vision, 'floaters'
describe what happens in rhegmatogenous retinal detachment
mechanical separation of sensory retina from retinal pigment epithelium
what signs and symptoms are seen in retinal detachment
painless visual loss, sudden onset flashers/floaters, may have RAPD, mat see tear on fundoscopy
what is the commonest cause of blindness in the UK, and what are the 2 different types
age related macular degeneration(AMRD)
types = wet AMRD (sudden visual loss) and dry AMRD(gradual visual loss
describe the mechanism behind wet AMRD
new blood vessel growth under the retina, leakage causes build up of fluid/blood and eventually scarring
what signs and symptoms are associated with wet AMRD
signs = haemorrhage/exudate symptoms = rapid central visual loss, distortion(metamorphopsia)
