Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 7-21: Ischemic Optic Neuropathy + Key Features Download Section PDF Listen +++ ++ Sudden painless visual loss with signs of optic nerve dysfunction Optic disk swelling in anterior ischemic optic neuropathy + Clinical Findings Download Section PDF Listen +++ ++ Anterior ischemic optic neuropathy Due to inadequate perfusion of the posterior ciliary arteries that supply the anterior portion of the optic nerve Produces sudden visual loss, usually with an altitudinal field defect, and optic disk swelling In older patients, it is often caused by giant cell arteritis The predominant predisposing factor is a congenitally crowded optic disk Other predisposing factors are systemic hypertension, diabetes mellitus, hyperlipidemia, systemic vasculitis, inherited or acquired hypercoagulable state (thrombophilia), obstructive sleep apnea, and therapy with interferon-alpha and phosphodiesterase type 5 inhibitors Diabetic papillopathy is a cause of chronic (possibly ischemic) optic disk swelling that generally has a better visual outcome In patients taking amiodarone, an optic neuropathy that can be difficult to differentiate from nonarteritic anterior optic neuropathy can develop (albeit rarely); it typically affects both eyes simultaneously and has a more chronic course Posterior ischemic optic neuropathy Involves the retrobulbar optic nerve and thus does not cause any optic disk swelling May occur with severe blood loss or nonocular surgery, particularly prolonged lumbar spine surgery in the prone position May be associated with dialysis + Diagnosis Download Section PDF Listen +++ ++ Clinical diagnosis (eg, visual loss accompanied by optic disease swelling, altitudinal field defect, crowded optic disk, temporal artery nodularity and tenderness, etc) + Treatment Download Section PDF Listen +++ ++ Emergency high-dose systemic corticosteroids Whether systemic or intravitreal corticosteroid therapy influences outcome in nonarteritic anterior ischemic neuropathy is uncertain Whether low-dose aspirin (~81 mg/day orally) reduces risk of fellow eye involvement is also uncertain Blood transfusion may be beneficial in treating marked anemia in patients with ischemic optic neuropathy who have undergone nonocular surgery