Visual Loss Flashcards
List the main causes of sudden visual loss
Vitreous haemorrhage Retinal detachment Wet age-related macular degeneration Closed-angle glaucoma Optic neuritis Stroke
What are the 2 main branches of the ophthalmic artery?
Central retinal artery
Posterior ciliary artery
Which part of the retina does the central retinal artery supply?
Inner 2/3 (including ganglion cells)
Which part of the retina does the posterior ciliary artery supply?
Outer 1/3 (photoreceptors, pigment layer)
Visual loss caused by central retinal artery occlusion is associated with pain. True/False?
False
Painless unless assoc. with GCA
Relative afferent pupillary defect is evident in central retinal artery occlusion. What is this?
When a light is shone on the right eye, the right eye constricts but the left eye dilates
Describe the appearance of the retina in central retinal artery occlusion
Pale
Oedematous
Thread-like vessels
Swelling
Outline ophthalmic management of central retinal artery occlusion within 24hrs
Ocular massage (try to convert CRAO into BRAO)
Outline vascular management of central retinal artery occlusion
Carotid Doppler (establish source) Manage risk factors
What is another name for transient central retinal artery occlusion?
Amaurosis fugax
Describe visual loss in amaurosis fugax
Transient/partial loss “like a curtain” that lasts up to 5mins with full recovery
Amaurosis fugax patients require immediate referral to which clinic?
TIA clinic
List causes of central retinal vein occlusion
Atherosclerosis
Hypertension
Hyperviscosity
Raised intra-ocular pressure
How does atherosclerosis cause central retinal vein occlusion?
Arterial thickening presses on vein to cause altered blood flow, resulting in stasis and occlusion
Describe the appearance of the retina in central retinal vein occlusion
Haemorrhages
Dilated, tortuous veins
Disc swelling
Macular swelling
Which growth factor may be suppressed as part of treatment for central retinal vein occlusion?
VEGF
The retina appears pale in central retinal artery occlusion and dark in central retinal vein occlusion. True/False?
True
Give another name for occlusion of the optic nerve head
Ischaemic optic neuropathy
Describe the pathogenesis of ischaemic optic neuropathy
Posterior ciliary arteries become occluded which results in infarction of the optic nerve head
What are the 2 types of ischaemic optic neuropathy?
Arteritic (painful, inflammation, GCA)
Non-arteritic (painless, atherosclerosis)
What are the 4 stages of visual loss, defined by testing?
Snellen chart
Counting fingers
Directional hand movement
Perception of light
Blindness in giant cell arteritis is irreversible. True/False?
True
List clinical features of giant cell arteritis
Jaw claudication Pulsating temporal artery Headache Visual loss Tender scalp Malaise
List clinical signs of a vitreous haemorrhage
Sudden visual loss
Floaters
Loss of red reflex
How is a vitreous haemorrhage managed?
Identify + treat cause
Vitrectomy for non-resolving cases
List clinical features of retinal detachment
Painless visual loss
Flashes of light, floaters
Relative afferent pupil defect
What is the commonest cause of blindness in the Western world in patients over 65?
Age-related macular degeneration (ARMD)
What is the difference between the two types of ARMD?
Wet - sudden visual loss
Dry - gradual visual loss
Describe the pathogenesis of wet ARMD
Angiogenesis under the retina with leakage/build up of fluid
Describe the appearance of an Amsler grid showing wet ARMD
Missing boxes = blind spot
Distorted lines = metamorphopsia (wavy lines)
Outline management of wet ARMD
Laser and PDT (traditionally)
Anti-VEGF injection (nowadays)
List the main causes of gradual visual loss (CARDIGAN)
Cataract ARMD (dry) Refractive error Diabetic retinopathy Inherited diseases Glaucoma Access to eye-clinic is Non-urgent
What is cataract? Describe pathogenesis
Clouding of the lens
Glucose converts to sorbitol which exerts osmotic effect to draw fluid in
Outline management of cataract
Surgical removal with intra-ocular lens implant if patient is symptomatic
Drusen may be seen in dry ARMD. What is this?
Waste products (yellow fat/protein deposits) below retinal pigment epithelium
There is no cure for dry ARMD. True/False?
True
Supportive vision aids may help
What is meant by refractive error?
Eye cannot clearly focus image
What is myopia?
“Short-sightedness”
Light focuses in front of the retina
What is hypermetropia?
“Long-sightedness”
Light focuses behind the retina
What is astigmatism?
Eye is shaped like a rugby ball as opposed to a football
What is presbyopia?
Loss of visual accommodation with age
What is glaucoma?
Progressive optic neuropathy, probably cause by raised IOP and fluid build-up
Which type of glaucoma is an ophthalmic emergency - open or closed -angle?
Closed-angle
List clinical features of closed-angle glaucoma
Painful red eye
Visual loss
Headache
Nausea, vomiting
Describe the appearance of the optic disc in glaucoma
Cupped disc
