Vision Loss and Blindness Flashcards
List all causes of sudden vision loss.
Vascular aetiology Retinal detachment Age related macular degeneration (ARMD) -wet type Closed angle glaucoma Optic neuritis Stroke
What provides the major blood supply to the eye?
various branches of OPHTHALMIC ARTERY
What vascular causes can lead to acute vision loss?
Occlusion of: - retinal circulation
- optic nerve head circulation
Haemorrhage from: - abnormal blood vessels (eg diabetes, wet ARMD)
- retinal tear
What are the signs of central retinal artery occlusion?
RAPD (relative afferent pupil defect)
Pale oedematous retina, thread-like retinal vessels
What are causes of central retinal artery occlusion?
Carotid artery disease
Emboli from the heart (unusual)
What is central retinal artery occlusion a type of?
stroke
How should you manage central retinal artery occlusion?
Ophthalmic management:
If presents within 24 hours,
Ocular massage (try to convert CRAO to BRAO)
Vascular management:
Establish source of embolus – carotid doppler
What are the 2 further variants of central retinal artery occlusion?
Branch retinal artery occlusion
Amaurosis fugax
What are the symptoms of Amaurosis fugax?
transient painless visual loss
‘like a curtain coming down’
lasts~5mins with full recovery
How should you manage Amaurosis fugax?
Immediate referral TIA clinic
Aspirin
Name the ocular cause of central retinal vein occlusion.
raised IOP (venous stasis)
What are the clinical signs of central retinal vein occlusion?
Retinal haemorrhages
Dilated tortuous veins
Disc swelling and macular swelling
What may be required in central retinal vein occlusion to avoid complications from new vessels formed eg vitreous haemorrhage)?
laser treatment
or more recently,
anti- VEGFs used
What is Occlusion of optic nerve head circulation also known as?
Also known as ‘Ischaemic optic neuropathy’
What happens in Occlusion of optic nerve head circulation?
Posterior ciliary arteries (PCA) become occluded, resulting in infarction of the optic nerve head
(PCA not end arteries)
What are the two types of Ischaemic Optic Neuropathy (ION)?
Arteritic 50% - inflammation (Giant Cell Arteritis)
Non-arteritic 50% - atherosclerosis
(Both cause sudden, profound visual loss with swollen disc)
What happens in arteritic ION?
Medium to large sized arteries inflamed (multinucleate giant cells)
Lumen of artery becomes occluded (posterior ciliary arteries)
Visual loss from ischaemia of optic nerve head
What is a sign of ION?
Pale, swollen disc
What are the visual symptoms of ateritic ION?
Sudden visual loss
Profound (CF – NPoL)
Irreversible blindness
What are 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
What can prevent the other eye going blind in ateritic ION?
Immediate high dose systemic steroid may prevent other eye going blind.
What is bleeding from retinal vessels usually associated with?
retinal tear
What is bleeding from abnormal vessels usually associated with?
with retinal ischaemia and new vessel formation eg after retinal vein occlusion or diabetic retinopathy
What are the symptoms of a Vitreous Haemorrhage?
vision loss
floaters
What are the signs of Vitreous Haemorrhage?
Loss of red reflex
No RAPD – unless associated with other pathology
What are the symptoms of retinal tear?
Painless loss of vision
Sudden onset of flashes/floaters (mechanical separation of sensory retina from retinal pigment epithelium)
Signs of retinal tear?
May have RAPD
May see tear on ophthalmoscopy
What are the two types of macular degeneration?
dry (gradual reduction in vision)
wet (sudden reduction in vision)
What happens in wet ARMD?
New blood vessels grow under retina – leakage causes build up of fluid/blood and eventually scarring
What are the symptoms and signs of wet ARMD?
Symptoms
Rapid central visual loss
Distortion (metamorphopsia)
Signs
haemorrhage/exudate
What is the treatment of wet ARMD?
Anti-VEGF treatment – injected into vitreous cavity. Stops new blood vessels growing by binding to VEGF (vascular endothelial growth factor)
Is gradual vision loss usually bilateral or unilateral?
bilateral
What does CARDIGAN stand for with regard to the causes of gradual vision loss?
Cataract
Age related macular degeneration (dry type)
Refractive error
Diabetic retinopathy (covered in other lecture)
Inherited diseases e.g. retinitis pigmentosa
Glaucoma
Access (to eye clinic) Non-urgent
Give 5 causes of cataracts.
Age related Congenital – intrauterine infection (importance of checking red reflex in neonates) Traumatic Metabolic – diabetes Drug-induced (steroids)
What is a Christmas tree cataract?
polychromatic cataract
Management of cataracts?
surgical removal with intra-ocular lens implant if patient is symptomatic
What are the symptoms and signs 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 for dry ARMD?
no treatment, just supportive management
What is Myopia?
short sightedness
What is Hypermetropia?
long sightedness
What is Astigmatism?
usually irregular corneal curvature
Presbyopia
long sightedness with age
What happens in open angle glaucoma?
Intra ocular pressure increases gradually
Damage of retinal nerve fibres
Visual field contracts
What are the signs of glaucoma (often no symptoms)?
Increased intraocular pressure
Cupped disc
Visual field defect
Treatment of open angle glaucoma?
pressure-lowering eye drops or occasionally surgery
