Vision Loss and Blindness Flashcards
what are the 2 types of visual loss
gradual
sudden
what are some causes of sudden vision loss
vascular problems (retinal artery/vein occlusion) vitreous haemorrhage retinal detachment Wet ARMD Closed angle glaucoma Optic neuritis Stroke
what arteries supply the eye
branches of the ophthalmic artery
what branches of the ophthalmic artery are most commonly occluded
posterior ciliary artery
central retinal artery
What are the 2 pathologies of the arterial supply to the eye
occlusion (of retinal or optic nerve circulation)
haemorrhage (from normal or abnormal blood vessels)
what are the symptoms of retinal artery occlusion
sudden painless vision loss
signs of retinal artery occlusion
RAPD Pale oedematous retina Treat-like vessels Dark macula Can see individual blood cells trickling through vessels
what are some causes of retinal artery occlusion
carotid artery disease
emboli from the heart (unusual)
what is amaurosis fugas
temporary painless vision loss in one eye “like a curtain coming down’ lasts 5 mins with full recovery
causes of amaurosis fugax
retinal artery occlusion
signs of amaurosis fugax
often nothing to see on exam as it has gone back to normal
urgent referral to stroke clinic- sign a stroke is on the way
what conditions are associated with central retinal vein occlusion
endothelial damage eg. diabetes
Abnormal blood flow eg. hypertension
Hypercoaguable states eg. cancer
symptoms of central retinal vein occlusion
sudden vision loss (variable)
signs of central retinal occlusion
retinal haemorrhages
dilated tortuous veins
disc swelling and macular swelling
what is ischaemic optic neuropathy
occlusion of the optic nerve head circulation
the posterior ciliary arteries become occluded resulting in infarction of the optic nerve head
which inflammatory condition causes ischaemic optic neuropathy
Giant cell arteritis
symptoms of ischaemic optic neuropathy
sudden severe visual loss
irreversible blindness
signs of ischaemic optic neuropathy
swollen optic nerve
pale swollen disc
what are some other symptoms of Giant Cell Arteritis
headache (temporal) jaw claudication scalp tenderness tender/enlarged scalp arteries amaurosis fugax malaise
what is vitreous haemorrhage
bleeding in the vitreous cavity: can be from normal vessels eg, bridging a retinal tear, or abnormal vessels
symptoms fo vitreous haemorrhage
loss of vision
floaters
signs of vitreous haemorrhage
loss of red reflex
may see haemorrhage on fundoscopy
need to find a cause
which type of macular degeneration causes sudden visual loss
Wet
pathology of wet ARMD
New blood vessels grow under the retina and leakage causes a build up of blood and eventually scarring
symptoms of wet ARMD
Rapid central visual loss
Distortion (straight lines become wavy)
signs of wet ARMD
haemorrhage/exudate
what is glaucoma
progressive optic neuropathy caused by an increase in IOP
what is closed angle glaucoma
aqueous humour can’t pass from posterior compartment to anterior so build up causing increased pressure
this can be acute (ophthalmic emergency)
symptoms of closed angle glaucoma
painful red eye sudden visual loss headache nausea vomiting
signs of closed angle glaucoma
red eye
cloudy cornea
dilated pupil
what are some causes of gradual visual loss
cataract ARMD (dry) Refractive error Glaucoma Diabetic retinopathy
what is cataracts
cloudiness of the lens due to abnormal changes in lens proteins
causes of cataracts
age related congenital traumatic metabolic drug induced (steroids)
cataract symptoms
gradual decline in vision (hazy/blurred) that cannot be corrected with glasses
may get glare
cataract treatment
surgical removal with intra-ocular lens implant (if patient is symptomatic)
symptoms of dry ARMD
gradual decline in vision
central vision missing (scotoma)
what are the signs of dry ARMD
Drusen (build up of waste products below retina)
Atrophic patches of retina
treatment for dry ARMD
No cure - just supportive treatment with low vision aids eg. magnifiers
what is a refractive error
when the eye cannot focus images clearly
what is myopia
‘short sightedness’
what is hypermetropia
‘long sightedness’
what is astigmatism
irregular corneal curvature doesn’t allow rays to be refracted to meet one point
what is presbyopia
loss of accommodation with ageing
what is open angle glaucoma
when the aqueous humour is not being drained properly
what are thy symptoms of open angle glaucoma
often none
opticians usually discover it
signs of opened angle glaucoma
cupped disc
visual field defect
May/may not have high IOP
