Visual Loss and Blindness Flashcards
visual loss can be either ______ or gradual
visual loss can be either SUDDEN or gradual
name some causes of sudden visual loss (5)
- vascular - CRAO/CRVO
- vitreous haemorrhage
- retinal detachment
- ARMD - wet
- closed angle glaucoma
name the major blood supply to the eye
branches of the ophthalmic artery
in sudden visual loss, there can be _________ of retinal artery/vein or ___________ from abnormal blood vessels in DM or wet ARMD
in sudden visual loss, there can be OCCLUSION of retinal artery/vein or HAEMORRHAGE from abnormal blood vessels in DM or wet ARMD
is there pain in CRAO?
no
is there sudden visual loss in CRAO?
yes
what are the signs of CRAO?
RAPD
pale oedematous retina
thread-like retinal vessels
what is the other name for transient CRAO?
amaurosis fugax
what are the symptoms of transient CRAO/amaurosis fugax
transient painless visual loss
‘like a curtain coming down’
lasts 5mins with full recovery
what is seen on examination of transient CRAO?
nothing abnormal on examination
what’s the management in transient CRAO?
urgent referral to stroke clinic
what is central retinal vein occlusion associated with?
endothelial damage - diabetes
abnormal blood flow - HBP
hypercoaguable state - cancer
VIRCHOW’S TRIAD
what are the signs and symptoms of CRVO?
sudden visual loss
retinal haemorrhage
dilated tortuous veins
disc and macular swelling
pale macula and optic disc with small vessels
diagnosis?
CRAO
dark macula with swelling of disc and tortuous vessels
diagnosis?
CRVO
what arteries are involved in optic nerve circulation?
posterior ciliary arteries
occlusion of optic nerve head circulate is also known as what?
ischaemic optic neuropathy (ION)
what becomes occluded and what infarcts in ION?
posterior ciliary arteries are occluded and optic nerve head becomes infarcted
what inflammatory condition causes ischaemic optic neuropathy?
giant cell arteritis - GCA
what cells are present in GCA?
multinucleate giant cells
what is the other name for GCA?
temporal arteritis
what are the visual symptoms of ION?
sudden severe visual loss
irreversible blindness
what are the signs of ION?
pale, swollen optic nerve/disc
immediate treatment of ION may prevent what?
bilateral visual loss
what are the other symptoms of GCA?
headache jaw claudication scalp tenderness tender and enlarged arteries malaise amaurosis fugax
where in the eye does haemorrhage often occur?
vitreous cavity - vitreous cavity
in vitreous haemorrhage, bleeding occurs from what?
abnormal vessels such as in DM or CRVO
normal vessels in bridging a retinal tear
what are the 2 symptoms of vitreous haemorrhage?
loss of vision
floaters
what sign is seen in vitreous haemorrhage?
loss of red reflex
is retinal detachment painful?
no
what is the symptom of retinal detachment?
sudden flashes/floaters
what are the signs of retinal detachment?
RAPD
tear on ophthalmoscopy
name the 2 types of ARMD
wet and dry
which ARMD causes sudden visual loss?
wet
where do the new vessels in wet ARMD grow from?
choroid - through pigment epithelium and into the retina
what are the symptoms of wet ARMD?
rapid central visual loss
what is seen on ophthalmoscopy of wet ARMD?
haemorrhage
exudate
which type of glaucoma causes sudden visual loss?
closed angle glaucoma
what happens in closed angle glaucoma?
increased pressure gradient causes iris to bow forward and obstruct trabecular meshwork
is closed angle glaucoma painful?
yes
what are the signs and symptoms of closed angle glaucoma?
painful red eye sudden headache nausea vomitting
cloudy cornea
dilated pupil
closed angle glaucoma treatment?
lower IOP with drops/oral medication to prevent blindness
name the causes of gradual visual loss (5)
cataract dry ARMD refractive error glaucoma diabetic neuropathy
define cataract
cloudiness of the lens due to abnormal changes in lens proteins (crystallins)
what are the causes of cataracts
age congenital metabolic steroids UVB
what is the other name for polychromatic cataract?
christmas tree cataract
name the 3 main cataract types
nuclear cataract
posterior subcapsular cataract
congenital cataract
what is the symptoms of cataract?
gradual decline in vision
glare - night when driving
what is the management of cataract?
surgical removal with intra ocular lens implant if patient is symptomatic
name the type of ARMD with gradual reduction in vision
dry ARMD
what is the symptoms of dry ARMD?
gradual loss of central vision
what is seen under the ophthalmoscope of someone with dry ARMD?
drusen
atrophic patches
dry ARMD treatment?
no treatment
what are the medical terms for the following refractive errors:
(a) short-sighted
(b) long-sighted
(c) irregular corneal curvature
(d) loss of accommodation with ageing
(a) myopia
(b) hypermetropia
(c) astigmatism
(d) presbyopia
refractive error treatment?
glasses
eye cannot focus properly
what are the symptoms of open angle glaucoma?
often none
optician may discover it
what are the signs of open angle glaucoma?
cupped disc
visual field defect
may/may not have IOP
what happens in open angle glaucoma?
drainage through the meshwork is poor
in myopia, the focus of rays is ______ the retina
in myopia, the focus of rays is BEFORE the retina
in hyperopia, the focus of rays is ______ the retina
in hyperopia, the focus of rays is BEHIND the retina
