Acute Loss of Vision

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Specials (Opthalmology) Flashcards on Acute Loss of Vision, created by Liam Musselbrook on 17/12/2016.
Liam Musselbrook
Flashcards by Liam Musselbrook, updated more than 1 year ago
Liam Musselbrook
Created by Liam Musselbrook over 7 years ago
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Question Answer
Key questions in history of acute loss of vision Headache - giant cell arteritis Eye movements hurt - optic neuritis Lights or flashes preceding visual loss - retinal detachment Like a curtain descending - retinal artery occlusion/giant cell arteritis
What are the the two types of retinal vein occlusion and what is it associated with? What kind of visual loss does it give? Central and branch retinal vein occlusion (CRVO and BRVO) Associations: age, diabetes, HTN, smoking, obesity, raised IOP, polycythaemia Unilateral visual loss
Non-ischaemic CRVO 75% of CRVO Variable VA Dilated, tortuous retinal veins Widespread haemorrhages Good prognosis Progression to ischaemic in ~30%
Ischaemic CRVO Sudden severe visual loss and more severe retinal signs Causes: glaucoma, polycythaemia, HTN Macular oedema Widespread cotton wool spots Deep haemorrhages Marked RAPD
Complications of ischaemic CRVO Permanent visual loss Neo-vascularisation (VEGF): - Risk of vitreous haemorrhage - Rubeotic glaucoma (new vessels on iris, blocking aqueous drainage) - Treat with pan-retinal photocoagulation and anti-VEGF agents
BRVO and its presentation 3x more common than CRVO Not an emergency (eg. OP appointment) Presentation: - Reduced VA (often central, worse on waking) - Visual field defects (often altitudinal)
What is seen on fundoscopy with BRVO? Findings restricted to area drained by affected vein Haemorrhage Cotton wool spots Venous dilatation Oedema
Central renal artery occlusion: Presentation Sudden unilateral severe decrease in VA (usually counting fingers or worse) May be complete loss of light perception RAPD (relative afferent pupillary defect) Cherry red spot on pale retina Intermittent prodrome phase common
What is seen on fundoscopy with CRAO? Pale retina (oedema) Cherry red spot (fovea contains photoreceptors only, supplied by choroid - for 6 weeks) Possible signs of hypertensive retinopathy
Management of CRAO Ocular massage, rebreathing into paper bag > hypercapnia and vasodilatation -> may dislodge embolus Acetazolamide, paracentesis (aspiration of aqeous from anterior chamber) - to lower IOP
What is Temporal Arteritis/Giant Cell Arteritis? Causes AION Immune-mediated vasculitis of medium and large vessels Overlaps with polymyalgia rheumatica (PMR)
Clinical features of temporal arteritis Typically patient > 60 years old Usually rapid onset (e.g. < 1 month) Headache (found in 85%) Jaw claudication (65%) Visual disturbances secondary to anterior ischemic optic neuropathy Tender, palpable temporal artery Features of PMR: aching, morning stiffness in proximal limb muscles (not weakness) Also lethargy, depression, low-grade fever, anorexia, night sweat
Management of temporal arteritis High-dose prednisolone - there should be a dramatic response, if not the diagnosis should be reconsidered
What is Anterior Ischaemic Optic Neuropathy and how does it present? Compromise of blood supply of optic nerve (posterior ciliary artery) Jaw claudication, tender scalp, temporal headache, abnormal temporal artery, decreased VA, RAPD, diplopia, optic disc swelling/atrophy
Investigations and management for AION Investigations: - CRP/ESR raised - Temporal artery biopsy (but high false -ve due to skip lesions) Management: - Oral prednisolone - May take >1 year to settle
Posterior vitreous detachment Degenerative changes in vitreous (liquefaction) leads to detachment from posterior retina Occurs earlier in myopia, trauma, inflammation, connective tissue disease Usually benign, leads to increased numbers of floaters
What are the complications of posterior vitreous detachment? Vitreous haemorrhage Retinal tear Retinal detachment
Retinal detachment: what can cause it, what are they more common in and where do they happen more rapidly? Causes: Vitreous detachment and retinal tear, trauma, surgery More common in myopes Detaches more rapidly in superior retina
How does retinal detachment present? 4 F's: Floaters, Flashes, Field loss, Fall in acuity (if macula involvement) Abnormal red reflex Grey, ballooning retina
Management of retinal tears and detachment Treat larger retinal tears with laser photocoagulation Surgical intervention for detachment
Optic neuritis Optic disc swelling Unilateral decrease in visual acuity over hours or days Blurring of vision (blind spot enlargement/paracentral scotoma) RAPD Red desaturation Retrobulbar aching Eye movements painful
Papilloedema Bilateral disc swelling due to increased ICP Headache Transient blurring of vision, enlarged blind spots May be splinter haemorrhages, exudates, cotton wool spots if severe Eventual atrophy
Causes of papilloedema Space-occupying lesion: neoplastic or vascular Malignant hypertension Idiopathic intracranial hypertension Hydrocephalus Hypercapnia Rare: hypoparathyroidism and hypocalcaemia, vitamin A toxicity
Optic atrophy Disc pallor from loss of axons, glial proliferation and decreased vascularity May occur without optic disc swelling, or following optic disc swelling
Causes of optic atrophy Papilloedema, optic neuritis, ischaemic optic neuropathy, POAG, optic nerve compression Retinal V/A occlusion Retinitis pigmentosa
Most common causes of sudden painless loss of vision Ischaemic optic neuropathy (e.g. temporal arteritis or atherosclerosis) Occlusion of central retinal vein Occlusion of central retinal artery Vitreous haemorrhage Retinal detachment
Differentiating posterior vitreous detachment, retinal detachment and vitreous haemorrhage
What does this show? Retinal detachment Features: - Dense shadow that starts peripherally progresses towards the central vision - A veil or curtain over the field of vision - Straight lines appear curved - Central visual loss
What does this show? Papilloedema
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