Visual loss and blindness Flashcards by Louise Emerson

what can cause sudden visual loss

vascular aetiology (retinal artery/ vein occlusion), vitreous haemorrhage, retinal detachment, ARMD wet type, closed angle glaucoma, optic neuritis, stroke

How well did you know this?

Not at all

Perfectly

what is the main blood supply to the eye

branches of the ophthalmic

How well did you know this?

Not at all

Perfectly

what supplies the optic nerve head

posterior cilliary artery

How well did you know this?

Not at all

Perfectly

what vessel supplies the retina

central retinal artery

How well did you know this?

Not at all

Perfectly

occlusion of what vasculature can cause sudden visual loss

retinal circulation (retinal artery and vein) 
optic nerve circulation

How well did you know this?

Not at all

Perfectly

what haemorrhage can cause sudden visual loss

abnormal vessels (DM, wet ARMD)
normal vessels (bridging a retinal tear)

How well did you know this?

Not at all

Perfectly

what are the signs and symptoms of central retinal artery occlusion

sudden visual loss
painless

RAPD
pale oedematous retina, thread like retinal

How well did you know this?

Not at all

Perfectly

why do oedematous retinal ganglions make the eye appear pale

as choroid blood vessels underneath that make the eye appear red are no longer visible

How well did you know this?

Not at all

Perfectly

why doesnt the macula get paler when ganglion cells become odematous (in central retinal artery occlusion)

as macula doesnt have ganglion cells over it

How well did you know this?

Not at all

Perfectly

what can cause central retinal artery occlusion

carotid artery disease

emboli from the heart (vegetations/ thrombus on heart valve)

How well did you know this?

Not at all

Perfectly

what is branch retinal artery occlusion

only one branch affected so partial vision loss

How well did you know this?

Not at all

Perfectly

how do you tell the vessels apart in a fundoscopy

lighter one is the artery

darker one is the vein

How well did you know this?

Not at all

Perfectly

what is amaurosis fugaxyout

transient central retinal artery occlusion

How well did you know this?

Not at all

Perfectly

what are the symptoms of amaurosis fugaxyout

transient painless visual loss
‘like a curtain coming down’
last about 5 mins with full recovery
nothing abnormal on examination

How well did you know this?

Not at all

Perfectly

what should you do in amaurosis fugaxyout

urgent referral to stroke clinic

How well did you know this?

Not at all

Perfectly

what is central retinal vein occlusion associated with

endothelial change (diabetes) 
abnormal blood flow (hypertension) 
hypercoaguable state (cancer)

(neighbouring artery may stiffen and occlude vein)

How well did you know this?

Not at all

Perfectly

what are the symptoms of central retinal vein occlusion

sudden visual loss

How well did you know this?

Not at all

Perfectly

what are the signs of central vein occlusion

retinal haemorrhages, dilates tortous veins, disc swelling and macular swelling, cotton wools spots

How well did you know this?

Not at all

Perfectly

what are cotton wool spots

ischaemia- small infarcts of the nerve fibres

How well did you know this?

Not at all

Perfectly

what are the differences in artery and vein occlusion

artery will cause oedema

vein will cause haemorrhages

How well did you know this?

Not at all

Perfectly

what is ischaemic optic neuropathy

occlusion of optic nerve head circulation (posterior ciliary arteries)

How well did you know this?

Not at all

Perfectly

what inflammatory condition can cause ischaemic optic neuropathy

giant cell arteritis - lumen of artery becomes occluded due to gross thickening of artery wall

How well did you know this?

Not at all

Perfectly

what cells id GCA

multinucleated giant cells

How well did you know this?

Not at all

Perfectly

what are the visual symptoms and signs of ischaemic optic neuropathy

sudden severe visual loss
irreversible blindness
swollen optic disc, pale

what can immediate treamtment of ischaemic optic neuropathy prevent

bilateral visual loss

what are the symptoms of GCA

``` headache (temporal) jaw claudication scalp tenderness (painful to comb hair) tender/enlarged scalp arteries amaurosis fugax (transient darkness) malaise ```

what is a vitreous haemorrhage

a haemorrhage that occurs in the vitreous cavity of the eye

what can cause an abnormal vessel haemorrhage

e.g. in retinal ischaemia in diabetes/ retinal vein occlusion new fragile (curly) blood vessels form which bleed easily

what are the signs and symptoms of vitreous haemorrhage

loss of vision floaters loss of red reflex may see haemorrhage on fundoscopy

what does the red reflex tell you

that the media is clear

what are the signs and symptoms of retinal detachment

painless loss of vision sudden onset of flashes/ floaters (mechanical separation of sensory retina from retinal pigment epithelium) may have RAPD may see tear on ophthalmoscopy

what causes ARMD

multifactoral- age, smoking, family history, poor nutrition

what are the types of ARMD

wet- sudden visual loss | dry- gradual

describe wet ARMD

new blood vessels grow under retina from pigment epithelium up through the choroid leakage causes build up of fluid/ blood and eventually scarring

what are the signs and symptoms of wet ARMD

rapid central visual loss distortion (metamorphosia) haemorrhage/ exudate eye pale due to oedema flecks in eye exudates from vessels

what is glaucoma

progressive optic neuropathy leads to optic nerve damage

what is the angle in glaucoma

angle between the iris and the cornea

what is the path of aqueous fluid

produced by the ciliary body, travels between the iris and lens into the trabecular meshwork

what causes closed angle glaucoma

aqueous humour encounters increased resistance through the iris/lens channel increased pressure gradient causes peripheral iris to bow forward, obstructing trabecular meshwork- increasing pressure

what are the signs and symptoms of closed angle glaucoma

acute (ophthalmic emergency) painful, red eye, sudden visual loss, headache, N&V red eye, cloudy cornea, dilated pupil

what is the treatment for closed angle glaucoma

lower IOP with drops/ oral medication to prevent blindness

what are the causes of gradual visual loss

cataract, ARMD (dry type), refractive error, glaucoma, diabetic retinopathy

what is cataracts

cloudiness of the lens- abnormal changes in lens proteins (crystallins) causes changes in their chemical and structural nature causing them to loose their transparency

what causes cataracts

age, congenital (intrauterine infection), traumatic, metabolic (diabetes- reductase glucose to sorbitol), drugs (steroids)

what are the different types of cataracts

nuclear posterior (subcapuslar) christmas tree (polychromatic) congenital

what are the symptoms of cataracts

gradual decline in vision (hazy/blurred) | glare

when is surgery done for cataracts

is patient is symptomatic

what is the commonest cause of blindness in western world in patients over 65

ARMD

what type of of ARMD do you get drusens in what are they?

dry type- they are bi products of pigment cells which build up and stop nutirents diffusing through the choroid- retina becomes atrophic

what are the signs and symptoms of dry type ARMD

gradual decline in vision central vision missing (scrotoma) drusen (yellow flakes) atrophic patches of retina

what is the treatment for dry type ARMD

none- vision aids

what is myopia

short sighted- image focused infront of the retina of the retina

what is hypermetropia

long sighted- image focused behind the retina

what is astigmatism

usually irregular corneal curvature

what is presbyopia

loss of accommodation with age

what is the treatment for refractive error

glasses

describe open angle glaucoma

Trabecular meshwork gets clogged up and doesn’t allow the fluid draining from the eye Pressure increases gradually

what are the signs and symptoms of open angle glaucoma

often none cupped disc visual field defect may/ not have raised IOP