Treatment of anterior ischemic optic neuropathy: Clues from the bench

Anterior ischemic optic neuropathy (AION) is due to optic nerve head ischemia, and there is currently no effective treatment. Age is a significant risk factor for both arteritic and nonarteritic AION (NAION), although we do not fully understand the changes that occur in aging that lead to selective vulnerability of the optic nerve head. Arteritic AION, which is most often seen in the setting of giant cell arteritis, is caused by vasculitis and thromboembolism of the ophthalmic circulation leading to impaired perfusion of the short posterior ciliary artery and infarction of the optic nerve head. More commonly, AION is nonarteritic, and vision loss is typically altitudinal and noted most commonly upon awakening. NAION has been associated with a variety of risk factors, including disc-at-risk, vascular risk factors including diabetes, vasospasm and impaired autoregulation, nocturnal hypotension, and sleep apnea. This review summarizes the clinical presentation of non-arteritic AION and arteritic AION associated with giant cell arteritis and the current and future treatment approaches for human NAION based on lessons from photochemical thrombosis models of NAION.