Non-arteritic Ischemic Optic Neuropathy
Sudden loss of vision caused by infarction of optic nerve Affects adults aged over 45 years Associated with diabetes, systemic hypertension, smoking, dyslipidemia, family history of arteriosclerosis or drop in systemic blood pressure Called "non-arteritic" to distinguish it from ischemic optic neuropathy associated with giant cell arteritis and other arteritides Visual loss mild to severe and largely irreversible No effective treatment
Optic disc usually swollen in acute phase and pale in chronic phase Usually monocular Visual acuity may be normal but visual field loss always present Afferent pupil defect on affected side No pain or other symptoms Onset often upon awakening Often history of aggressively treated systemic hypertension
Arteritic ischemic optic neuropathy in giant cell arteritis , but that is usually accompanied by headache, jaw pain provoked by chewing ("jaw claudication"), limb girdle joint pain, fatigue, malaise, low-grade fever, and elevated sedimentation rate and/or C-reactive protein Optic neuritis , usually occurring in younger patients Papilledema , usually binocular with relatively preserved vision Neoplastic optic neuropathy, usually with previously known cancer
Refer urgently to ophthalmologist because of concern for arteritic ischemic optic neuropathy in giant cell arteritis
Visual loss may progress over 14 days, largely irreversible, but often mild Similar process may affect other eye in 10% to 15% of patients within 10 years Best way to reduce second-eye involvement is to address arteriosclerotic risk factors and avoid aggressive lowering of systemic blood pressure
