Sudden, painless loss of vision Flashcards
3 broad causes of visual loss
vascular
retinal
neurological
Vascular causes of visual loss (4)
central retinal artery occlusion
central retinal vein occlusion
vitreous haemorrhage
amaurosis fugax
Retinal causes of visual loss (2)
Retinal detachment
Retinitis:
-CMV, HSV, VZV
-acute retinal necrosis/progressive outer retinal necrosis are severe variants.
Neurological causes of visual loss (5)
Optic neuritis
migraine
ischaemic optic neuropathy:
-GCA
-non-arteritic
compression e.g. thyroid eye disease and tumours
damage to optic tract e.g. pituitary apoplexy
Diagnostic questions and causes (6)
headache?:
-GCA>do ESR
-migraine
painful eye movements?: optic neuritis
feels like curtain coming down? (amaurosis fugax):
-TIA in retinal artery
-GCA
flashing lights before visual loss?: retinal detachment
Hx of uncontrolled DM?: vitreous haemorrahge from new vessel formation
acutely painful, red eye w. halos/blurring before: acute angle glaucoma
Ix for sudden visual loss (3)
acuity
pupillary reflexes
fundoscopy
Pathology, subtypes and fundoscopy of anterior ischaemic optic neuropathy (3)
posterior ciliary arteries which supply optic nerve are blocked by atheroma/inflammation
can be arteritic or non-arteritic
fundoscopy shows pale, oedematous optic disc.
symptoms and signs of GCA (5)
malaise jaw claudication scalp tenderness/pain on brushing hair neck pain Ex shows pulseless temporal artery
Ix, Dx and Rx of GCA (4)
ESR and CRP
Dx via temporal artery biopsy
Rx w. prednisolone PO for >1yr
if there is visual loss, give IV methylprednisolone
RFs and Rx for non-arteritic AION and differentiating freatures from A-AION (3)
RFs same as those for atherosclerosis
can Rx w. steroids-improves prognosis for vision
A-AION presents w. complete visual loss whereas NA-AION presents with partial visual loss.
Sources of vitreous haemorrhage (3)
new vessels
retinal tears/trauma
retinal detachment
symptoms and signs of vitreous haemorrhage (3)
small extravasations of blood>vitreous floaters (black dots/rings)
large haemorrhages can cause:
-visual loss
-loss of red reflex
Ix and Rx of vitreous haemorrhage (3)
B-scan (USS) to identify source
should resorb blood spontaneously
may require partial/complete vitrectomy if significant
Cause, presentation, signs and fundoscopy of central retinal artery occlusion
embolus from carotids/heart most common cause
presents w. severe vision loss with sudden onset
RAPD-can precede retinal changes by 1 hr
fundoscopy:
-whitened retina
-cherry-red spot on macula
(look for signs of atherosclerosis: DM, bruits, smoking, HTN etc)
DDx for central retinal artery occlusion (5)
GCA-do ESR
retinal detachment-peripheral loss>closing in, straight lines appear curved
anterior ischaemic optic neuropathy-pale, oedematous optic disc
vitreous haemorrhage-floaters, loss of red reflex
acute closed angle glaucoma-clouded cornea, painful eye, floaters
Mx of central retinal artery occlusion (4)
(90 mins before permanent loss) ocular massage acetazolamide to lower IOP anterior chamber paracentesis to lower IOP antihypertensive e.g. timolol (aim to increase ocular perfusion)
Causes/associations of retinal vein occlusion (3)
glaucoma
atherosclerosis, DM, HTN
polycythaemia
Presentation of retinal vein occlusion
slower onset than retinal artery occlusion
loss of acuity>blindness
worse on waking
RAPD
(visual loss due to ischaemia and oedema)
complications of retinal vein occlusion (2)
rubeosis iridis: new vessel formation on the iris due to ischaemia and release of vascular growth factors
raised IOP>corneal decompensation, infection and perforation>GLAUCOMA
Classification and features of retinal vein occlusion (6)
non-ischaemia:less serious, may not have decreased acuity
ischaemic: cotton-wool spots, swollen optic nerve,risk of neovascularisation, macular oedema
Fundoscopical features of retinal vein occlusion (5)
stormy sunset appearance swollen optic disc from vascular congestion haemorrhage in all four quadrants oedema cotton-wool spots
Mx of retinal vein occlusion (4)
fluorescein angiogram to assess degree of ischaemia
to treat neovascularisation:
-pan-retinal photocoagulation
to prevent oedema:
-intra-vitreal anti-VEGF 1st line
-intra-vitreal steroids 2nd line e.g. triamcinolone
Branch retinal vein occlusion features and Rx (2)
retinal ischaemia>VEGF release>neovascularisation
Rx w. photocoagulation
symptoms and signs of optic neuritis (4)
loss of acuity over hours to days>central scotoma-usually unilateral pain on eye movement RAPD colour vision affected-esp. red (usually have had previous episodes)
