W136 Sudden Visual Loss Flashcards
Signs and symptoms pf lens dislocation?
- diplopia (blurry)
- can’t focus properly
- iridodensis (iris may quiver)
Management of dislocation?
First line: glasses
Then: remove and replace lens if fully dislocated (rare)
Signs and symptoms of lens haemorrhage?
- Sudden, painless vision loss
- No RAPD
- Can be haziness, floaters or full loss
Causes of lens haemorrhage?
- Trauma
- Diabetic retinopathy
Together account for 90% cases
What is found on fundoscopy for haemorrhage of lens?
- Decreased red reflex
- Hazy red (blood)
Investigations for haemorrhage of lens?
- Fluorescein angiography to find nevascularisation
- Fundoscopy
- Intra-occular pressures
- Slit lamp examination
Management of lens haemorrhage?
Laser photo-coagulation for stopping neovascularisation
Anterior retinal cryotherapy (ARC) for clearance of fresh blood
What is wet age-related macular degeneration?
Sometimes called neovascular AMD –
Develops when abnormal blood vessels form underneath the macula and damage its cells.
How is wet AMD different to dry?
- more acutely severe
- no drusen (deposits) in wet AMD
- no macular neovascularisation in dry AMD
Signs and symptoms of wet AMD?
- No RAPD (ususally)
- Sudden visual distortion
- Central blank patch or blurring
- Typically >55 years old
Findings on fundoscopy for wet AMD?
- macular oedema
- usually subretinal haemorrhages (from neovascularisation)
centred around the macular
Management of wet AMD?
- Intra-ocular injections of anti-angiogenic drugs (anti-VEGF).
- Fluorescein angiography (find nevascularisation sites)
- Colour fundus photography (to provide record of retina).
- Psychological support.
What is (central) retinal artery occlusion? (CRAO)
Central - artery occluded more medially and so has more drastic effect on vision and orbit function.
Elsewhere- occlusion of retinal artery more distil-ly into the orbit; has bifurcated and will have less severe effect.
Signs and symptoms of Central Retinal Artery Occlusion?
- RAPD
- Reduced acuity
- Sudden, unilateral, painless, loss of vision
What is seen on fundoscopy for central retinal artery occlusion?
Cherry red spot!
Pale retina
What do you want to make sure you rule out before diagnosing central retinal artery occlusion?
Giant cell arteritis!
Causes of central retinal artery occlusion?
- hypertension
- diabetes
- embolus
- giant cell arteritis (make sure to rule out)
Management of central retinal artery occlusion?
- Lower intra-ocular pressure
- Re-perfuse ischaemic tissue quickly.
Nothing else to do really.
Signs and symptoms of (central) retinal vein occlusion?
- Sudden, painless, unilateral loss of vision (complete or partial depends on vein occluded)
- RAPD if severe
- Papilloedema - enlargement of blind spot and blurring; that can develop into optic atrophy
What do you find on fundoscopy for Central Retinal Vein Occlusion?
- Mottled appearance; ‘ketchup’ fundus
- Retinal haemorrhages (tortuous, dilated retinal veins)
- Macular oedema
- Cotton wool spots
Management of ventral retinal vein occlusion?
Treat the macula oedema!
- pan-retinal photocoagulation laser treatment
- dexamethasone implants
- Triamcinalone
Nothing else really. Treat underlying cause.
Signs and symptoms of retinal detachment?
- Painless
- RAPD
- Progressive loss of vision - see floaters, flashing lights, peripheral vision loss (localised defect).
- Suspect on history
What would you find on fundoscopy for retinal detachment (RD)?
- Red reflex abnormal
- Detached retina looks grey and wrinkled (not always visible)
- Follow on with a slit lamp examination of retina.
Management of retinal detachement?
- Laser therapy
- Cryo therapy
- Reattachment surgery
Good prognosis.
Causes of retinal detachment?
- retinal tear - allowing fluid behind
- trauma
- diabetic retinopathy
What is acute angle closure glaucoma?
Is a less common type of glaucoma:
Occurs when the part of the eye that drains fluid becomes blocked, causing pressure to build up in the eye.
Signs and symptoms of acute angle closure glaucoma?
- Bilateral and painful
- Blurred vision - diplopia
- Headaches
- Nausea
- Seeing ‘halo’s’ around lights
- (RAPD sometimes)
On investigation and examination what would you find in acute angle closure glaucoma?
- Raised intraoccular pressure (IOP)
- Red eye
- Hazy cornea
- Irregular pupil
- Firm globe (due to raised IOP)
- ‘Shadow sign’ seen in pupil when light flashed in (indicates shallow anterior chamber)
Management of acute angle closure glaucoma?
- Pilocarpine eye drops
- Anti-emetics (if acute phase)
- Laser treatment
- Surgery; iridotomy
Main treatment focuses on reducing IOP.
What does pilocarpine do?
- Is a parasympathomimetic
- Mimics effect of ACh on muscarinic receptors.
- Opens up network in trabecular meshwork.
- Reverses myadriasis (dilated pupil)
Side affects of pilocarpine/ parasympathomimetics?
- Headache,
- burning,
- stinging,
- myopia,
- risk of retinal detachment.
What is anterior ischaemic optic neuropathy?
If optic blood vessels become very narrow or blocked for any reason, the nerve cannot function properly and the sight in the eye may be very poor.
Causes of anterior ischaemic optic neuropathy (AION)?
- VIAGRAAAAAA
- Multiple sclerosis
- Atherosclerotic causes
Signs and symptoms of AION?
- Painless
- RAPD
- Signs of temporal arteritis
- Rapidly progressive loss of vision
- Decreased colour vision.
What do you see on fundoscopy for AION?
A pale, swollen optic disk.
Why does blood supply affect the optic nerve?
Because anatomy.
Management for AION?
Treat underlying cause.
e.g. MRI if suspect multiple sclerosis
What is this called and where would the lesion be?
Bitemporal hemianopia
Chiasmal lesion
What is this called and where would lesion be?
Homonymous hemianopia
Optic tract lesion
What is mononuclear field loss and where would lesion be?
Loss of sight in one eye.
Optic tract lesion.
