visual loss and blindness Flashcards
What can cause a painful sudden vision loss?
• Angle closure glaucoma • Uveitis • Corneal ulcer keratitis • Endophthalmitis • Retrobulbar optic neuritis • Orbital cellulitis Giant cell arteritis
What can cause a painless fleeting visual loss?
• Embolic retinal artery occlusion
• Migraine
• Raised ICP
Prodromal in giant cell arteritis
What can cause a painless prolonged vision loss
- Ischaemic optic neuropathy
- Retinal artery occlusion
- Retinal vein occlusion
- Retinal detachment
- Age-related macular degeneration (wet)
- Other macula disease
- Vitreous haemorrhage
- Orbital disease affecting optic nerve
- Intracranial disease affecting the visual pathway
What can cause a gradual vision loss with a cloudy media?
Opacities in cornea, lens, or vitreous appear black against the red reflex
• Corneal opacity
• Cataract
Vitreous haemorrhage
What can cause a gradual visual loss with a clear media?
Retinal disorder: • Age-related macular degeneration (dry) • Macular/retinal dystrophy Optic nerve/pathyway disorder: • Optic neuropathy Central nervous disease affecting visual pathways
What are the symptoms of a CRAO?
- Sudden visual loss
- Profound (counting fingers or less)
- Painless
What are the signs of a CRAO?
- RAPD (relative afferent pupil defect)
- Pale oedematous retina, thread-like retinal vessels
- Retinal nerve fibre layer becomes swollen except at fovea (cherry red spot)
What are the causes of a CRAO?
NB this is a type of stroke
• Carotid artery disease
• Emboli from heart – unusual
What is the management of a CRAO?
• Ophthalmic management
o If presents within 24 hours - ocular massage (try to convert CRAO to BRAO)
• Vascular management
o Establish source of embolus – carotid doppler
o Assess and manage risk factors
What is amaurosis fugax?
transient CRAO
What are the symptoms, signs and management of amaurosis fugax?
Symptoms
ν transient painless visual loss
ν ‘like a curtain coming down’
ν lasts~5mins with full recovery
Signs
ν Usually nothing abnormal to see on examination
Treatment:
-Immediate referral TIA clinic
ν Aspirin
ν Other cause of TVL: Migraine – visual loss usually followed by headache
What are the causes of a CRVO?
Can be either branched vein or central vein
If branched may be asymptomatic or may be aware loss of part of field
Systemic causes: • Atherosclerosis } • Hypertension } Virchow’s triad • Hyperviscosity } The vein lies underneath artery and if the artery becomes hardened with atherosclerosis it can push down on vein and occlude it
Ocular causes:
• raised IOP (venous stasis)
what are the symptoms and signs of a CRVO?
Symptoms:
• Sudden visual loss
• Moderate to severe visual loss (6/9 – P of L)
Signs:
• Retinal haemorrhages (flame shaped haemorrhages)
• Dilated tortuous veins
• Disc swelling and macular swelling
What is the treatment for CRVO?
- Based on treatment of systemic or ocular causes (eg hypertension, diabetes, glaucoma)
- Monitor : may develop complications due to development of new vessels (laser treatment may be required to avoid complications from these vessels eg vitreous haemorrhage)
- More recently, anti- VEGFs used (VEGF = vascular endothelial growth factor)
What is ischaemic optic neuropathy?
This is the occlusion of optic nerve head circulation
• Posterior ciliary arteries (PCA) become occluded, resulting in infarction of the optic nerve head
• (PCA not end arteries)
Flame haemorrhages may be seen