Blurred Vision Flashcards
Painful acute, red-eye, blurred vision
Corneal ulcer
Uveitis
Glaucoma (AACG)
See red eye deck
Chronic blurred vision
Diabetic retinopathy/maculopathy --> see systemic diseases deck Glaucoma (POAG) Cataract Dry age-related macula degeneration See gradual loss of vision deck
Painless acute, white-eye, blurred vision
Central retinal artery occlusion/Central retinal vein occlusion
Wet age-related macula degeneration –> gradual vision loss deck
Non-arteritic Anterior ischemic optic neuropathy
Giant cell arteritis (arteritic anterior ischemic optic neuropathy)
Retinal detachment
Retinal vein occlusion
Blockage of a central or peripheral retinal vein -> peripheral may show local haemorrhage
Second most common retinal vascular disorder, more common in people over 65yrs
May be due to thrombus formation or compression by adjacent arterioles
Central Retinal vein occlusion - risk factors
Atherosclerotic -> age, diabetes, raised cholesterol and hypertension, smoking and obesity
Raised IOP
Inflammatory/coagulative diseases –> sarcoidosis or myeloma, protein C or S deficiencies
Central Retinal vein occlusion - complications
Backlog of blood and hypoxia causes leakage of blood contents.
Ischemic damage leads to VEGF - causing new vessel growth which can cause haemorrhage or neovascular/’90 day’ glaucoma if they clog the trabecular meshwork
Permanent macula or optic atrophy
Central Retinal vein occlusion - Non-ischaemic
Milder, 75%, may resolve fully with good outcomes or progress to ischaemic type
Mild or absent afferent pupillary defect
Widespread dot-blot and flame haemorrhages throughout the fundus - some disc oedema
Central Retinal vein occlusion - Ischaemic
Rarer and more severe - can lead to a painful blind eye or neovascular glaucoma –> rarely linked to retinal detachment
Severe visual impairment and afferent pupillary defect
Similar fundus appearance to non-ischaemic but disc oedema is more severe - haemorrhage scattered in ‘blood-storm’ pattern with cotton wool spots
Central Retinal artery occlusion - management
No proven treatment options
Identify and modify risk factors
Recognise and treat complications
Ischaemic CRVO observation and panretinal photo coagulation therapy if they show signs of neovacularization near the iris
Non-ischaemic central Retinal artery occlusion - outcome
<10% recover normal vision, 50% have persistent impairment of 6/60 or worse
1/3 develop ischaemic type within 3 years
Presentation acuity predicts acuity outcome
Ischaemic central Retinal artery occlusion - outcome
Very poor due to macula oedema and ischaemia
>90% have impaired vision of 6/60 or worse
60% develop neovascularisation and 50% develop it around the iris (rubeosis iris) - usually between 2-4 months later
Require monitoring, may need panretinal photocoagulation (PRP)
Branch/peripheral retinal artery occlusion
3x as common as CRVO,
Presentation and prognosis depends on occlusion location and affect on macula drainage - a hemiretinal occlusion is proximal enough to affect half of retinal drainage
Fundoscopy will show vessel dilation/tortuousity + haemorrhage
Treatment for Branch/peripheral retinal artery occlusion
Refer to ophthalmologist
Some benefit from PRP treatment if there is macula oedema
Triamcinolone treatment has anatomical and functional benefits in reducing macula oedema but increases the risk of glaucoma/cataracts etc
Dexamethasone implants can be used to treat macula oedema
RPE
Retinal pigment epithelium
Retinal artery occlusions - anatomy
Outer layer of RPE, photoreceptors and overlying tissue are supplied by the choroid –> supplied by various cillary arteries, branches of the ophthalmic artery
The inner neural retina is supplied by the central retinal artery directly from the ophthalmic, which divides into 4, superior and inferior nasal and temporal branches
Retinal artery occlusions - causes
80% - atherosclerosis related thrombus, hypertension accounts for 60% of these, diabetes is co-morbid in 25%
Embolism - from carotid, cardiac or aorta
Inflammatory - giant cell arteritis, wegener’s, SLE
Rarely infectious, pharmacological or ophthalmic causes
Central retinal artery occlusion
Blockage before it branches incidence 8.5/million/year
Mostly in elderly pts, in young it is usually due to valve disease
Presents as sudden, unilateral, painless vision loss –> close to total blindness - Hx of amaurosis fugax in 10% of pts
Bilateral in 1-2% of cases, not necessarily symmetrical
Amaurosis fugax
A transient monocular visual loss usually due to a temporary reduction in retinal artery blood flow