Visual Loss and Blindness Flashcards
What vascular problems can cause sudden visual loss?
- Occlusion of either retinal or optic nerve circulation
- Haemorrhage
What symptoms present when the central artery of the retina is occluded?
Sudden visual loss with no PAIN
What signs can show a central retinal artery occlusion
- RAPD (relative afferent pupil defect - slight dilatation)
- Pale oedematous retina
- thread-like retinal vessels
Emboli from where can cause Central Retinal Artery Occlusions (CRAO)?
- Carotid artery disease
- Emboli from the heart (unusual)
**type of stroke
Occlusion of a branch of the retinal artery can cause what?
Amaurosis fugax - transient occlusion
“curtain coming down”
What symptoms present in an occlusion of a branch of the retinal artery?
- transient painless visual loss
- ‘like a curtain coming down’
- lasts around 5mins with full recovery
Any transient CRAO requires urgent referral to the stroke clinic. TRUE/FALSE?
TRUE
How is a central retinal vein occlusion commonly caused?
Endothelial damage e.g. diabetes
Abnormal blood flow e.g. hypertension
Hypercoaguable state e.g. cancer
A central retinal vein occlusion presents with variable sudden vision loss. TRUE/FALSE?
TRUE
What signs are present on fundoscopy when there has been a central retinal vein occlusion?
- Retinal haemorrhages
- Dilated tortuous veins
- Disc and macular swelling
Describe the main difference on fundoscopy for CRAO and CRVO?
CRAO = pale with thin vessels CRVO = dark with tortuous vessels
Infarction of the head of the optic nerve is caused by an occlusion in which artery?
Posterior ciliary arteries
Infarction of the optic nerve head is known as what condition?
Ischaemic optic neuropathy
What other condition can cause ischaemic optic neuropathy?
Giant Cell/ Temporal Arteritis
causes lumen of posterior ciliary arteries to become occluded
The sudden visual loss caused in ischaemic optic neuropathy is irreversible. TRUE/FALSE?
TRUE
What other symptoms may be present in giant cell arteritis?
- Headache (usually temporal)
- Jaw claudication
- Scalp tenderness (painful to comb hair)
- Tender/enlarged scalp arteries
- Amaurosis fugax
- Malaise
Why do abnormal vessels haemorrhage into the vitreous cavity?
Retinal ischaemia in diabetes OR retinal vein occlusion => abnormal, fragile new blood vessels form and leak
When would normal blood vessels haemorrhage into the vitreous cavity?
When bridging a retinal tear
What symptoms and signs indicate a vitreous haemorrhage
- Loss of vision
- ‘Floaters
- Loss of red reflex
What are the common symptoms of retinal detachment
- Painless loss of vision
- Sudden onset of flashes/floaters (mechanical - separation of sensory retina from retinal pigment epithelium)
How does a detached retina appear on fundoscopy
pale
curled up
oedematous
What type or age related macular degeneration can cause sudden visual loss?
Wet
dry type causes gradual sight loss
Describe the pathogenesis of wet ARMD
- New blood vessels grow under retina
- Leakage causes build up of fluid/blood
- eventually scarring develops
What symptoms do patients with wet ARMD experience?
- Rapid central visual loss
- Distortion (metamorphopsia)
