Visual loss Flashcards
what ‘ABCD’ causes sudden visual loss
A: ARMD (wet), B: bleed/ blocked vessel (vitreous haemorrhage, occlusion), C: closed angle glaucoma, D: detached retina
what is the most common cause of blindness in the UK
age related macular degeneration
what is the pathophysiology of wet ARMD
abnormal new vessels grow under retina (choroid) mediated by VEGF, leakage causes fluid build up (oedema) which leads to scarring
what are symptoms (4) and signs (3) of wet ARMD
rapid central visual loss / blind spots (scotoma) / distortion (metamorphosia) / decreased brightness of colours / haemorrhage and hard exudates on retina (normal colour) / DRUSEN: yellow deposits of proteins and lipids / atrophic retina
how do you identify wet vs dry ARMD
OCT scan - drusen a key identification for ARMD
how do you treat wet ARMD
intravitreal injections and anti VEGF eg ranibizumab
what can causes a central retinal artery occlusion (CRAO)
carotid artery disease - (hypertension, stroke, atherosclerosis), emboli
what are symptoms (2) and signs (4) of a CRAO
sudden visual loss / painless / pale and oedema retina / thread like vessels, cherry red macula / (relative afferent pupil defect - pupils dilate in affected eye - must be V severe)
what is a brach retinal artery/ vein occlusion (BRA/VO)
branch off of central retinal artery/ vein - not as severe as not an end artery so not whole of retina is ischaemic
what is amaurosis fugax
transient painless visual loss / black curtain loss for a few minutes / usually from emboli
what is virchow’s triad
hypercoaguble state (eg cancer) /abnormal flow (eg hypertension) / endothelial damage (eg diabetes)
what are symptoms and signs of central retinal vein occlusion (CRVO) (5)
sudden visual loss / retinal haemorrhages / dilated torutous veins / disc swelling (hard to see cup and cone) and macular swelling /cotton wool spots (ischamia)
what is occlusion of optic nerve head
AKA ischaemic optic neuropathy (ION) - posterior ciliary arteries which are blood supply to CNII become occluded
what are symptoms and signs of ischaemic optic neuropathy (3)
sudden, painless visual loss, swollen optic disc
what is ION associated with
temporal arteritis (polymyalgia rheumatica, headache, claudication, tenderness)
what is a vitreous haemorrhage
bleeding from vessels into vitreous
what can cause vitreous haemorrhage
abnormal vessels from neovascularisation / new vessels eg retinal tear
what are symptoms and signs of a vitreous haemorrhage (4)
loss of vision / floaters / loss of red reflex / haemorrhage on fundoscopy
what is a closed angle glaucoma
increased pressure in eye from build up aqueous fluid/ blocked trabecular drainage network AND iris blocks access to drainage (closed angle)
what are symptoms of closed angle glaucoma
(emergency), VV intense eye pain and headache / nausea and vomiting / sudden visual loss and halos / Females
what are signs of closed angle glaucoma
acute red eye / cloudy cornea / dilated pupil (high pressure causes ischaemia and sphincter muscles cant contract)
how do you treat closed angle glaucoma
zap hole in iris with laser, drugs: pilocarpine (miotic that constricts pupil), acetazolamide is a carbonic anhydrase inhib that reduces aqueous production)
what can cause retinal detachment
with age vitreous becomes watery and can get in behind retina and pull it away
what are symptoms of retinal detachment
painless, sudden visual loss / sudden FLASHES and FLOATERS of light in periphery / floaters
what are signs id retinal detachment
‘crinkly’ retina / may have RAPD / may see tear / may have vitreous bleed
what are the ABCDG of gradual vision loss
ARMD (dry) / Blur (refraction) / Cataracts / Diabetes/ Glaucoma
what is the difference between wet and dry ARMD
no neovascularisation in dry type
what are symptoms (1) and signs (2) of dry ARMD
gradual central visual loss / drusen on fundoscopy / atrophic retina
how do you manage dry ARMD
no definitive treatment just visual aids
what is blur or refractive error
light does not focus clearly on retina and eyes cannot focus and image - v common
what is myopia
short sighted
what is hypermetropia
long sighted
what is astigmatism
irregularly shaped cornea
what is presbyopia
loss of accommodation with age
what are cataracts and what is the process that causes it
very common clouding/ opification of the lens by abnormal changes in lens proteins (crystallin)
what are 4 types of cataracts
nuclear / posterior sub-capsular / Christmas tree cataract AKA polychromatic / congenital
what can cause cataracts (5)
DIABETES, UV damage, hypertension, smoking, steroids
how does diabetes cause cataracts
increases sugar in lens (sorbitol) which causes swelling and fibre disruption
what are symptoms (4) and signs (1) of cataracts
gradual visual loss to hazy and blurry / opaque eye (unilateral) / changes in colour to brown or yellow / starbursts around light / LOSS OF RED REFLEX
what is the main treatment of cataracts
surgical removal with intra-ocular lens implant
what are symptoms of open angle glaucoma
often asymptomatic as so subtle and vision loss in periphery
what should the cup to disc ration be and what is it in glaucoma
should be 0.6, in glaucoma >0.6
