Visual loss and blindness Flashcards
What are some causes of sudden visual loss?
vascular aetiology retinal detachment age related macular degeneration - wet type Close angle glaucoma optic neuritis stroke
What is the major arterial blood supply to the eye?
ophthalmic artery
What are the two types of vascular events that can lead to sudden visual loss?
occlusion haemorrhage
Occlusion of what can result in sudden visual loss?
retinal circulation optic nerve head circulation
haemorrhage from what can cause sudden visual loss?
abnormal blood vessels - diabetes retinal tear
What are the symptoms of central retinal artery occlusion?
sudden painless visual loss
What signs are seen in central retinal artery occlusion?
relative afferent pupil defect pale oedematous retina thread-like retinal vessels
What does this image show?
central reinal artery occlusion
What are some causes of central retinal artery occlusion?
carotid artey disease
emboli from the heart - unusual
What is the management of a central retinal artey occlusion
if presents within 24 hrs - occular massage
Establish source of embolus - carotid doppler
assess and manage risk factors
What are the 3 main variants of retinal artery occlusion?
Central retinal artey occlusion
Branch retinal artery occlusion
Amaurosis fugax
what is Amaurosis fugax?
TRANSIENT CRAO
(transient - short lasting)
what are the symptoms of amaurosis fugax?
transient painless visual loss
like a curtain coming down
lasts 5 mins with full recovery
what are the signs in amaurosis fugax?
usually nothing abnormal on examination
What is the treatment for amaurosis fugax?
immediate referral to the TIA clinic
aspirin
What are some causes of transient vision loss?
amaurosis fugax
migraine - visual loss usually followed by a headache
what are some systematic causes of central retinal vein occlusion?
Virchow’s triad
atherosclerosis
hypertension
hyperviscosity
What is an ocular cause of central retinal vein occlusion?
raised IOP
what are the symptoms of central retinal vein occlusion?
sudden visual loss (moderate to severe)
What are the signs of a central retinal vein occlusion?
retinal haemorrhages
dilated tortuous veins
disc swelling and macular swelling
What does this image show?
central retinal vein occlusion
what is the treatment for central retinal vein occlusion?
treat systemic / ocular cause
monitor - complications due to development of new vessels
anti-VEGFs
what is occlusion of the optic nerve head circulation also known as?
ischaemic optic neuropathy
In nOcclusion of optic nerve head circulation what vessels become occluded?
What does this result in?
posterior ciliary arteries - infarction of the optic nerve head
what are the 2 types of ischaemic optic neuropathy?
arteritic - inflammation
non-arteritic - atherosclerosis
How does ischaemic optic neuropathy present?
sudden, profound visual loss with swollen disc
outline the pathogenesis for arteritic ischaemic optic neuropathy
Giant cell arrteritis (GCA)
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 are the symptoms of arteritic ischaemic optic neuropathy?
sudden visual loss
irreversible blindless
what is giant cell arteritis also known as?
temporal arteritis
What are the symptoms of temporal arteritis?
- Headache (usually temporal)
- Jaw claudication
- Scalp tenderness (painful to comb hair)
- Tender/enlarged scalp arteries
- amaurosis fugax
- malaise
what invesigations could be done for suspected temporal arteritis?
very high ESR, PV and CRP
temporal artery biopsy may be helpful
In arteritic iscahemic optic neuropathy how can visual loss in the other eye be prevented?
prompt recognition
immediate high dose systemic steroid
in sudden visual loss due to haemorrhage where doe the haemorrhage often occur?
into the vireous cavity
what are symptoms of virteous harmorrhage?
loss of vision
floaters
what are signs of virteous haemorrhage?
lossof red reflex
may see haemorrhage on fundoscopy
What is the managemet of virteous haemorrhage?
idenify the cause
Vitrectomy for non-resolving cases
what are the symptoms of retinal detachment?
painless loss of vision
sudden onset of flashes / floaters
what is the commonest cause of blindness in the western world in patients over 65?
Age related macular degeneration (ARMD)
what are the 2 types of ARMD?
dry and wet
What is the key difference between wet and dry ARMD?
dry - gradual vision loss
wet - sudden vision loss
what happens in wet ARMD?
New blood vessels grow under retina – leakage causes build up of fluid/blood and eventually scarring
What are the symptom of wet ARMD?
rapid central visual loss
distorsion
What signs may be seen in wet ARMD?
haemorrhage / exudate
what does VEGF stand for?
vascular endothelial growth factor
What is the treatment for wet ARMD?
Anti-VEGF treatment – injected into vitreous cavity. Stops new blood vessels growing by binding to VEGF
what are some common features of gradual visual loss?
usually bilateral
often asymmetrical
may present early with reduced visual acuity
may present late with decreased field
What are some causes of gradual visial loss? (CARDIGAN)
- Cataract
- age related macular degeneration - dry
- refractive error
- diabetic retinopathy
- inherited diseases
- glaucoma
- access (to eye clinic) Not urgent
What is a cataract?
cloudiness of the lens
What are some differen types of cataract?
Nuclear cataract
posterior subcapsular cataract
christmas tree cataract - polychromatic cataract
congenital cataract - check red reflex in neonates
how are cataracts managed?
surgical removal with intra-ocular lens implant if patient is symptomatic
what are the symptoms of dry ARMD?
gradual decline in vision
central vision missing
What are some signs of dry ARMD?
drusen - build up of waste
atrophic patches of retina
what is the treatment of dry ARMD?
no cure - treatment i supportive with low vision aids
what is a refractive error?
when the eye cannot clearly focus on image
What are the different types of refractive errors?
Myopia - short sighted
hypermetropia - long sighted
astigmatism - rugby ball shaped cornea
presbyopia - loss of accomodation with ageing
what is the main treatment for refractive errors?
Glasses
what is glaucoma?
progressive optic neuropathy resulting in visual loss
which type of glaucoma can be acute?
closed angle type - ophthalmic emergency
How do patients with closed angle type glaucoma present?
with painful, red eye/visual loss/headache/nausea/vomiting
how is closed angle type glaucoma treated?
Need to lower IOP with drops/oral medication to prevent patient going blind
what are the symptoms of open-angle glaucoma?
often none - tends to be discovered by opticians
what signs are commonly seen in open angle glaucoma
cupped disc
visual field defect
may/may not have high IOP
