• Ocular ischaemic syndrome

    by  • 16/07/2014 • Ophthalmology

    Definition:is the constellation of ocular signs and symptoms secondary to severe, chronic arterial hypoperfusion to the eye, often secondary to carotid artery stenosis.

    Amaurosis fugax is a form of acute vision loss caused by reduced blood flow to the eye that may be a warning sign of an impending stroke.

    Classification / type of disease:

    Epidemiology: typically between 50-80, M:F (2:1).

    Presenting symptoms / signs:vision loss secondary to hypoperfusion, dull radiating ache over the eye and eyebrow, ocular angina, pt may also may report arterial hypertension, diabetes mellitus, coronary artery disease, previous stroke, and hemodialysis

    Diagnostic investigations: On dilated examination, there may be blot retinal hemorrhages along with dilated and beaded retinal veins. The ocular perfusion pressure is decreased. The corneal layers show edema and striae. There is mild anterior uveitis. A cherry-red spot in macula may be seen, along with cotton-wool spots elsewhere, due to retinal nerve fiber layer hemorrhages.

    High clinical suspicion should be kept for painless vision loss in patients with atherosclerosis, deep venous thrombosis, atrial fibrillation, pulmonary thromboembolism or other previous embolic episodes

     

    Aetiology: Severe ipsilateral or bilateral carotid artery stenosis or occlusion is the most common cause

    The syndrome has been associated with occlusion of the common carotid artery,internal carotid artery, and less frequently the external carotid artery. Other causes include:

    • Takayasu’s arteritis
    • Giant cell arteritis
    • Severe ophthalmic artery occlusion, due to thromboembolism
    • Surgical interruption of anterior ciliary blood vessels supplying the eye, particularly during extensive strabismus surgery on 3 or more rectus muscles, leading to an anterior segment ischemic syndrome.

    Complications:If carotid occlusive disease results in ophthalmic artery occlusion, general ocular ischemia may result in retinal neovascularization, rubeosis iridis, cells and flare, iris necrosis, and cataract. The condition leads to neovascularization in various eye tissues due to the ischemia. The eye pressure may become high due to associated neovascular glaucoma. An ischemic optic neuropathy may eventually occur.

    Pathophysiology:

    Transmission

    Treatment / management:  

    500 mg intravenous (i.v.) acetazolamide and 100 mg i.v. methylprednisolone (for possible arteritis). Additional measures include paracentesis of aqueous humor to decrease IOP acutely. 

    At a later stage, pan-retinal photocoagulation (PRP) with an argon laser appears effective in reducing the neovascular components and their sequelae.

    Prognosis: poor to fair depending on speed of intervention and degree of severity

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