Vision Loss Flashcards
Give 5 causes of sudden visual loss?
Vascular aetiology, vitreous haemorrhage, retinal detachment, wet ARMD, closed angle glaucoma
What type of visual loss do optic neuritis and stroke cause?
Sudden
Where does the main blood supply to the eye come from?
Branches of the ophthalmic artery
What artery supplies the inner two thirds of the retina?
Central retinal artery
What gives the blood supply to the outer third of the retina?
Choroid
Where do the posterior ciliary arteries supply?
Optic nerve head (optic disc)
Sudden visual loss of a vascular aetiology can be caused by occlusion of what?
Retinal circulation or optic nerve head circulation
Sudden visual loss of a vascular aetiology can be caused by haemorrhage of what?
Abnormal blood vessels or a retinal tear
What 2 conditions can cause abnormal blood vessels to form in the eye?
Diabetic retinopathy or wet ARMD
Describe the visual loss which is encountered in CRAO?
Sudden, painless and profound
What are some signs of CRAO?
Relative afferent pupil defect. Pale, oedematous retina with thread like vessels. Cherry red spot on macula
What does this show?
Central retinal artery occlusion.
(pale, oedematoous retina with thread like vessels)
CRAO is a type of stroke. What can this occur secondary to? Which is most common?
Occurs secondary to carotid artery disease mostly, very rarely as a result of an emboli from the heart.
What is the first line management for CRAO if it presents within 24 hours?
What is the purpose of this treatment?
Ocular massage- try to convert it to a branch occlusion which causes less overall damage.
If the patient presents with a CRAO after more than 24 hours, or an ocular massage has already been performed, what is the next management?
Find the source of the embolus with a carotid doppler, and assess and manage risk factors.
What is amaurosis fugax?
Transient CRAO causing visual loss ‘like a curtain coming down’. Usually lasts about 5 minutes with full recovery and no abnormalaities on examination.
What is the management for amourosis fugax?
Urgent referral to the stroke clinic and possibly start aspirin therapy
What are systemic causes of CRVO?
Atherosclerosis, hypertension, hyperviscosity
What is the ocular cause of CRVO?
Raised IOP
Describe the visual loss in CRVO?
Sudden, moderate-severe
What are some signs of CRVO?
Retinal haemorrhages, dilated, torturous veins, swollen disc and macula
What does this show?
Central retinal vein occlusion
What does this show?
Normal macula
What does this show? (Not anything specific, just in general)
Macular oedema
Why do you need to monitor patients with CRVO?
They may develop complications due to new vessel growth
What new treatment can be used for CRVO? What do these do?
Anti-VEGF- prevent new vessel growth
What does this show?
Why are these patients likely to have visual loss?
Branch retinal vein occlusion- likely to have visual loss as a result of macular oedema
What is the major difference on fundoscopy between an artery and vein occlusion?
Artery occlusion will be pale and vein occlusion will be dark
What is occlusion of the optic nerve head circulation known as?
Ischaemic optic nerve neuropathy
What arteries supply the optic nerve head?
Posterior ciliary arteries
Are the posterior ciliary arteries end arteries?
No
What are the 2 types of optic nerve head occlusion? How common are each one?
Arteritic and non-arteritic (each make up 50% of cases)
What causes arteritic optic nerve head occlusion?
Inflammation due to GCA
What causes non-arteritic optic nerve head occlusion?
Atherosclerosis
What does optic nerve head occlusion cause?
Sudden, profound vision loss with a swollen disc
What does this show?
Ischaemic optic nerve
(pale, swollen disc)
What are the optic symptoms of arteritic ION?
Why is diagnosis of this very important?
Sudden, profound, irreversible blindness
To prevent visual loss in the other eye
What test is important in diagnosis of GCA?
What immediate treatment may be required?
Temporal artery biopsy
Immediate high dose steroids
Where does haemorrhage normally occur in the eye?
Into the vitreous cavity
What are symptoms of vitreous haemorrhage?
Loss of vision and floaters
What are signs of vitreous haemorrhage?
Loss of red reflex and may see haemorrhage on fundoscopy
What is the management for vitreous haemorrhage?
Identify the cause and if there is no cause then vitrectomy
What does this show?
Vitreous haemorrhage
What are symptoms of retinal detachment?
Painless loss of vision and sudden onset of flashes/floaters
What are signs of retinal detachment?
RAPD, may see tear on retina, pale retina
What does this show?
Where will the visual disturbance be?
What is the management?
Retinal detachment
Superior
Usually surgical
What does this show?
What type of visual loss does it cause?
Wet ARMD
Rapid, central vision loss
What happens in wet ARMD?
New blood vessels grow under the retina, and leakage causes a build-up of fluid/blood and eventually scarring.
What are some risk factors for wet ARMD?
Smoking, poor nutrition, positive family history
What is the treatment for wet ARMD?
Anti-VEGF
What happens in closed angle glaucoma?
Aqueous humour encounters increased resistance through the iris/lens channel. This obstructs the trabecular meshwork and causes the IOP to rise.
How may closed angle glaucoma present acutely?
Present with painful red eyes, visual loss, headaches, nausea and vomiting.
What is the treatment for closed angle glaucoma?
Lower IOP with drops/oral medication to prevent the patient going blind and then do a laser iridotomy.
How may gradual visual loss present early?
How may gradual visual loss present late?
Decreased visual acuity
Decreased visual fields
Give 5 causes of gradual visual loss?
Glaucoma, dry ARMD, diabetic retinopathy, cataract, refractive error
What is a cataract?
What drug commonly causes this?
Clouding of the lens
Steroids
What are some symptoms of cataract?
Gradual decline in vision which cannot be corrected with glasses
Glare
What is the treatment for a cataract?
Surgical removal with intra-ocular lens implant if patient is symptomatic
What condition may result in the gradual loss of central vision?
Dry ARMD
What is the treatment for dry ARMD?
No treatment- can use magnifiers
What is myopia?
Short sightedness- patients focus images too far forward
What is hypermetropia?
Long sightedness- patient focus images too far back
What is astigmatism?
Irregular corneal curvature
What is presbyopia?
Loss of accomodation with age
Open angle glaucoma is often asymptomatic. What are some signs?
Cupped disc
Visual field defect
May or may not have high IOP
What does this show?
Open angle glaucoma
