visual loss and blindness Flashcards Preview

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Flashcards in visual loss and blindness Deck (34):

What can cause a painful sudden vision loss?

• Angle closure glaucoma
• Uveitis
• Corneal ulcer keratitis
• Endophthalmitis
• Retrobulbar optic neuritis
• Orbital cellulitis
Giant cell arteritis


What can cause a painless fleeting visual loss?

• Embolic retinal artery occlusion
• Migraine
• Raised ICP
Prodromal in giant cell arteritis


What can cause a painless prolonged vision loss

• Ischaemic optic neuropathy
• Retinal artery occlusion
• Retinal vein occlusion
• Retinal detachment
• Age-related macular degeneration (wet)
• Other macula disease
• Vitreous haemorrhage
• Orbital disease affecting optic nerve
• Intracranial disease affecting the visual pathway


What can cause a gradual vision loss with a cloudy media?

Opacities in cornea, lens, or vitreous appear black against the red reflex
• Corneal opacity
• Cataract
Vitreous haemorrhage


What can cause a gradual visual loss with a clear media?

Retinal disorder:
• Age-related macular degeneration (dry)
• Macular/retinal dystrophy
Optic nerve/pathyway disorder:
• Optic neuropathy
Central nervous disease affecting visual pathways


What are the symptoms of a CRAO?

• Sudden visual loss
• Profound (counting fingers or less)
• Painless


What are the signs of a CRAO?

• RAPD (relative afferent pupil defect)
• Pale oedematous retina, thread-like retinal vessels
• Retinal nerve fibre layer becomes swollen except at fovea (cherry red spot)


What are the causes of a CRAO?

NB this is a type of stroke
• Carotid artery disease
• Emboli from heart – unusual


What is the management of a CRAO?

• Ophthalmic management
o If presents within 24 hours - ocular massage (try to convert CRAO to BRAO)

• Vascular management
o Establish source of embolus – carotid doppler
o Assess and manage risk factors


What is amaurosis fugax?

transient CRAO


What are the symptoms, signs and management of amaurosis fugax?

ν transient painless visual loss
ν ‘like a curtain coming down’
ν lasts~5mins with full recovery

ν Usually nothing abnormal to see on examination

-Immediate referral TIA clinic
ν Aspirin
ν Other cause of TVL: Migraine – visual loss usually followed by headache


What are the causes of a CRVO?

Can be either branched vein or central vein
If branched may be asymptomatic or may be aware loss of part of field

Systemic causes:
• Atherosclerosis }
• Hypertension } Virchow’s triad
• Hyperviscosity }
The vein lies underneath artery and if the artery becomes hardened with atherosclerosis it can push down on vein and occlude it

Ocular causes:
• raised IOP (venous stasis)


what are the symptoms and signs of a CRVO?

• Sudden visual loss
• Moderate to severe visual loss (6/9 – P of L)

• Retinal haemorrhages (flame shaped haemorrhages)
• Dilated tortuous veins
• Disc swelling and macular swelling


What is the treatment for CRVO?

• Based on treatment of systemic or ocular causes (eg hypertension, diabetes, glaucoma)
• Monitor : may develop complications due to development of new vessels (laser treatment may be required to avoid complications from these vessels eg vitreous haemorrhage)
• More recently, anti- VEGFs used (VEGF = vascular endothelial growth factor)


What is ischaemic optic neuropathy?

This is the occlusion of optic nerve head circulation
• Posterior ciliary arteries (PCA) become occluded, resulting in infarction of the optic nerve head
• (PCA not end arteries)
Flame haemorrhages may be seen


What are the two types of ischaemic optic neuropathy?

• Arteritic 50% - inflammation (GCA)
• Non-arteritic 50% - atherosclerosis

Both cause sudden, profound visual loss with a pale, swollen disc


What is the pathogenesis of artheritic ION?

• Giant cell arteritis (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 giant cell arteritis in the eye?

• Sudden visual loss
• Profound (CF – NPoL)
• Irreversible blindness
• Important as diagnosis and immediate treatment may prevent bilateral visual loss

Risk of sudden complete blindness in second eye and can be fatal


What are the systemic symptoms of giant cell arteritis?

• Headache (usually temporal)
• Jaw claudication
• Scalp tenderness (painful to comb hair)
• Tender/enlarged scalp arteries
• Amaurosis fugax
• Malaise
• Very High ESR , PV and CRP
• Temporal artery biopsy may help diagnosis


What is the management of giant cell arteritis?

• Prompt recognition (approx. 40 cases each year in Tayside)
• Immediate high dose systemic steroid may prevent other eye going blind.


Vitreous haemorrhage:
-what vessels can this stem from?

Bleeding occurs from abnormal vessels
• Associated with retinal ischaemia and new vessel formation eg after retinal vein occlusion or diabetic retinopathy

Bleeding occurs from retinal vessels
• Usually associated with a retinal tear


What are the symptoms of a vitreous haemorrhage? what are the signs?

Symptoms of vitreous haemorrhage:
• Loss of vision
• ‘floaters’

Signs of vitreous haemorrhage:
• loss of red reflex
• No RAPD – unless assoc. with other pathology


What is the treatment of a vitreous haemorrhage?

• Identify cause
• Vitrectomy for non-resolving cases


Retinal detachment:
-What are the symptoms
-what are the signs?

• Painless loss of vision
• Sudden onset of flashes/floaters (mechanical separation of sensory retina from retinal pigment epithelium)
• ‘like a curtain falling down’

• May have RAPD
May see tear on ophthalmoscopy


What is the treatment for a retinal tear?



What can cause a retinal tear?

• a tear can occur in retina, and liquefied vitreous can gain entry into the sub retinal space and the retina detaches progressively
• it can be pulled off by contracting fibrous tissue on the retinal surface e.g. in the proliferative retinopathy of diabetes
• rarely fluid can accumulate in the sub-retinal space as a result of an exudative process which may occur with retinal tumours or during toxaema of pregnancy


-what is this?
-what are the symptoms?
-what are the signs?
-what is the treamtnet?

• New blood vessels grow under retina – leakage causes build up of fluid/blood and eventually scarring

• Rapid central visual loss
• Distortion (metamorphopsia)

• haemorrhage/exudate

• laser
• photodynamic therapy
• Anti-VEGF treatment – injected into vitreous cavity. Stops new blood vessels growing by binding to VEGF (vascular endothelial growth factor)


-what is this?
-what are the symptoms?
-what are the signs?
-what is the treamtnet?

As the retinal pigmented epithelium removes and processes the used discs of the photoreceptor outersegment, over time the undigested lipid products accumulate and the excess material is transferred to the membrane between the RPE and the choroid. Extracellular deposits that form here are yellow, discrete lesions called drusen

• Gradual decline in vision
• Central vision ‘missing’

• Drusen – build up of waste products below RPE
• RPE changes – atrophy/hyperplasia

• No cure – treatment is supportive with low vision aids e.g. magnifiers


What are 'floaters' in the eye?

With ageing the vitreous gel undergoes degenerative changes with liquefaction and formation of fragments in condensed vitreous
This casts shadows on the retina = floaters
Obscure vision only slightly/ more prominent in bright sunlight


What is posterior vitreous detachment?

Posterior vitreous detachment:
Sometimes in older patients or myopes, the vitreous gel collapses and separates from points of retinal attachment – posterior vitreous detachment


What are the acute symptoms of a posterior vitreus detachment?

Acute symptoms:
• Flashing lights (photopsia)
• Shower of floater
• Sometime vitreous haemorrhage can occur if blood vessel is ruptured


what is retinitis pigmentosa?

Retinitis pigmentosa (RP) is a group of rare, genetic disorders that involve a breakdown and loss of cells in the retina.


What are the clinical features of retinitis pigmentosa?

night blindness is often the initial sign
tunnel vision due to loss of the peripheral retina (occasionally referred to as funnel vision)
fundoscopy: black bone spicule-shaped pigmentation in the peripheral retina, mottling of the retinal pigment epithelium


what are the assoc. syndromes with retinitis pigmentosa?

Refsum disease: cerebellar ataxia, peripheral neuropathy, deafness, ichthyosis
Usher syndrome
Lawrence-Moon-Biedl syndrome
Kearns-Sayre syndrome
Alport's syndrome