Anterior ischemic optic neuropathy (AION), or optic nerve-head infarction, is the most common optic nerve disorder of the elderly except for glaucoma. There are two types of AION. The less common arteritic AION is associated with giant cell arteritis and was described more than 3000 years ago.1 The pathophysiology of arteritic AION is well understood and consists of occlusion of the small posterior ciliary arteries supplying the anterior optic nerve. The diagnosis is suggested by the characteristic clinical findings of temporal ache or tenderness, polymyalgia rheumatica, and jaw claudication, as well as laboratory evidence of an elevated erythrocyte sedimentation rate. The diagnosis is proven by finding granulomatous inflammation with giant cells on biopsy of the temporal artery. Immediate high-dose corticosteroid therapy is mandatory, is usually effective prophylaxis for involvement of the other optic nerve, and may even reverse visual loss in occasional cases.
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