Sudden loss of vision Flashcards
causes of sudden loss of vision
optic neuritis, retinal artery occlusion, anterior ischaemic optic neuropathy (GCA), vitreous haemorrhage, transient visual loss, retinal detachment, acute closed angle glaucoma, migraine
what is anterior ischaemic optic neuropathy
optic nerve is damaged. post ciliary arteries blocked by inflammation or atheroma
what is seen on fundoscopy AION
pale swollen optic disc
what is the cause of arteritic AION
GCA: other eye at risk until steroids given. malaise, jaw claudification, tender scalp, temporal arteries and neck pain
tests in GCA
high ESR, high CRP
treatment GCA
prednisolone 80mg /24h
associations non arteritic AION
incr bp, incr lipids, DM, smoking.
what is vitreous haemorrhage due to
retinal new vessels, retinal tears, retinal detachment, trauma
what are vitreous floaters
small extravasations of blood- small black dots or ring like forms
treatment vitreous haemorrhage
spontaneous- absorption. dense VH- vitrectomy
what happens in optic neuritis
unilateral loss of acuity over hours-days. colour vision affected- red desaturation. eye movements hurt.
what does the pupil show in optic neuritis
afferent defect- absent direct response but consensual response is present
disc appearance in optic neuritis
normal in 60%; swollen, blurred, hyperaemic, temporal pallor
what does temporal pallor suggest in optic neuritis
past attack of optic neuritis in the same eye
how long does recovery take optic neuritis
2-6 weeks. 45-80% develop MS.
causes optic neuritis
MS, syphilis, Lebers optic atrophy, diabetes, vitamin deficiency,
treatment optic neuritis
high dose methylprednisolone, then prednisolone
what should you think if the vision loss is transient
vascular cause
typical causes transient vision loss
vascular, TIA, migraine, MS, subacute glaucoma, papilloedema
how soon is the visual loss in central retinal artery occlusion
within seconds of occlusion. afferent pupil defect within seconds
appearance of retina in central retinal artery occlusion
white with cherry red spot at the macula
what happens to acuity in central retinal artery occlusion
decreases
what is the occlusion due to in central retinal artery occlusion
usually thromboembolic- signs of atherosclerosis, bruits, incr BP, heart disease, diabetes
treatment central retinal artery occlusion
if seen within 6h aim is to increase retinal blood flow by reducing IOP- ocular massage, surgical removal aqueous from ant chamber or use of antihypertensives
what happens if a single branch of the retinal artery is occluded
retinal and visual changes relate only to the part of retina supplied
which is commoner- central retinal vein or artery occlusion
retinal vein
associations central retinal vein occlusion
arteriosclerosis, incr BP, diabetes and polycythaemia, glaucoma (all types)
which visual loss is more sudden retinal vein or artery
artery
what is visual loss due to in central retinal vein occlusion
ischaemia and macular oedema
what is central retinal vein occlusion divided into
non ischaemic- better acuity and prognosis, less dramatic signs; and ischaemic
what is used to see degree of ischaemia central retinal vein occlusion
fundus fluorescin angiogram
signs on fundoscopy central retinal vein occlusion ischaemic
cotton wool spots, swollen optic nerve, macular oedema, risk of neovascularisation)
treatment central retinal vein occlusion
bevacizumab, lasers, dexamethasone intravitreal implants
branch retinal vein occlusion signs
unilateral visual loss, fundal appearances in the corresponding area
what does retinal ischaemia lead to
release VEGF (vascular endothelial growth factor) and retinal new vessel formation
how to treat neovascularisation
laser photocoagulation
how does the retinal vein occlusion look under fundoscopy
hyperaemia, haemorrhages- stormy sunset
other causes sudden visual loss
retinal detachment, acute glaucoma, migraine
is sudden bilat visual loss usual
no- suspect CMV retinitis in HIV patient
what type of eyes are more prone to retinal detachment
myopic
what happens in retinal detachment
holes/tears in retina allow fluid to separate sensory retina from retinal pigment epithelium
what does retinal detachment present with
4 F’s- floaters, flashes, field loss, fall in acuity
what can retinal detachment be due to
rhegmatogenous, 2ary to intraocular problem- melanoma, diabetes; after cataract surgery, trauma
if there is a superior detachment where is the field loss
inferior
treatment retinal detachment
vitrectomy and gas tamponade, scleral silicone implants
