Visual Loss and Blindness Flashcards
List causes of Sudden Visual Loss
Vascular aetiology
Retinal detachment
Age related macular degeneration (ARMD) -wet type
Closed angle glaucoma
Optic neuritis
Stroke
What are the causes of sudden visual loss form a vascular aetiology?
Occlusion of - retinal circulation
- optic nerve head circulation (posterior ciliary arteries)
Haemorrhage from
- abnormal blood vessels (eg diabetes, wet ARMD)
- retinal tear
What are the signs and symptoms of CRAO?
Symptoms
Sudden visual loss
Painless
Signs
RAPD (relative afferent pupil defect)
Pale oedematous retina, thread-like retinal vessels
What is the manin cause of central retinal artery occlusion?
Carotid Artery Disease
What is the management of CRAO?
Carotid Doppler to assess location of embolism
If patient presents within 24 hours give an occular massage to try and convert CRAO to BRAO
What condition presents with:
transient painless visual loss
‘like a curtain coming down’
lasts~5mins with full recovery
How would you treat it?
amaurosis fugax
Immediate referal
Aspirin
What are causes of central retinal vein occlusion?
Systemic causes
Atherosclerosis
Hypertension
Hyperviscosity
**Ocular causes ** raised IOP (venous stasis)
What are the signs and clinical features of CRVO?
Sudden, moderate to severe visual loss
Retinal haemorrhages
Dilated tortuous veins
Disc swelling and macular swelling
CRVO treatment
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)
anti- VEGFs used (VEGF = vascular endothelial growth factor)
What are the causes of venous and arterial occlusion?
Arterial- embolic
Venous- Stasis
Which arteries become occluded in ischaemic optic neuropathy?
the posterior ciliary arteries
what are the two causes of ischaemic optic neuropathy?
Arteritic- Inflammation (Giant Cell Arteritis)
Non-Arteritic- Atherosclerosis
what are the signs and symptoms of Giant Cell Arteritis?
Headache (usually temporal)
Jaw claudication
Scalp tenderness (painful to comb hair) Tender/enlarged scalp arteries
Amaurosis fugax
Malaise
Very High ESR , PV and CRP
Temporal artery biopsy may help diagnosis
how do you treat giant cell arteritis
High Dose Steroids
What are the signs, symptoms and mangement of a vitreous haemorrhage?
Symptoms
Loss of vision
‘Floaters’
Signs
Loss of red reflex
No RAPD – unless associated with other pathology
Management
Identify cause
Vitrectomy for non-resolving cases
Describe the pathology of ‘wet’ age related macular degeneration
New blood vessels grow under retina – leakage causes build up of fluid/blood and eventually scarring
What are the signs and symptoms of ‘Wet’ ARMD?
Symptoms
Rapid central visual loss
Distortion (metamorphopsia)
Signs
haemorrhage/exudate
what are the signs and symptoms of ‘Dry’ ARMD?
Symptoms
Gradual decline in vision
Central vision ‘missing’
Signs
Drusen – build up of waste products below RPE
RPE changes – atrophy/ hyperplasia
what is the treatment of ‘Dry’ ARMD?
No cure – treatment is supportive with low vision aids eg magnifiers
What is the pathology of open angle glaucoma?
Intra ocular pressure increases gradually
Damage of retinal nerve fibres
what are the signs and symptoms of open angle Glaucoma?
Symptoms
Often NONE
Optician screening important
Signs
Increased intraocular pressure
Cupped disc
Visual field defect
How does vision loss develop in Glaucoma?
how do the numbers relate to the letters on the snellen chart?
