Ischemic optic neuropathy is the most common acute optic nerve disorder in patients over age 50 years . Ischemic optic neuropathy is generally categorized as anterior (affecting the optic disc) versus posterior (retrobulbar), and as arteritic versus nonarteritic. Anterior involvement is usual with both arteritic and nonarteritic ischemic optic neuropathy.
Nonarteritic anterior ischemic optic neuropathy (NAION) is the most common form of ischemic optic neuropathy. It is an idiopathic, ischemic insult of the optic nerve head characterized by acute, monocular, painless visual loss with optic disc swelling.
This topic will discuss the prognosis and treatment of NAION. The epidemiology, pathogenesis, etiologies, clinical features, and diagnosis of NAION are discussed separately. Other forms of ischemic optic neuropathy and other optic neuropathies are discussed separately. (See "Nonarteritic anterior ischemic optic neuropathy: Epidemiology, pathogenesis, and etiologies" and "Nonarteritic anterior ischemic optic neuropathy: Clinical features and diagnosis" and "Clinical manifestations of giant cell (temporal) arteritis" and "Optic neuropathies".)
Visual prognosis — After the onset of NAION, vision may deteriorate in some patients over the first few days or weeks. In the Ischemic Optic Neuropathy Decompression Trial (IONDT), 207 patients with an initial visual acuity of 20/64 were reevaluated within 30 days; 29 percent of these patients had progressed . Others report that among patients with a broad spectrum of visual loss at presentation, 5 to 11 percent of patients have significant visual acuity worsening over this time period [3,4].
After this initial period of potential visual decline, most patients stabilize or improve; 25 to 40 percent of patients can have significant improvement in visual acuity [3,5]. Continued progression is unusual; progressive worsening should prompt investigation into alternative causes of vision loss. (See "Nonarteritic anterior ischemic optic neuropathy: Clinical features and diagnosis", section on 'Diagnosis'.) In the IONDT, 43 percent of patients with an initial baseline visual acuity of 20/64 or worse had significantly improved vision (three lines or more) at six months; 31 percent had sustained this degree of recovery at 24 months [6,7]. No specific demographic factor or comorbidity (eg, age, gender, diabetes, hypertension) has been associated with visual outcome .