Treatment of nonarteritic anterior ischemic optic neuropathy

Abstract

Nonarteritic anterior ischemic optic neuropathy (NAION) is the most common clinical presentation of acute ischemic damage to the optic nerve. Most treatments proposed for NAION are empirical and include a wide range of agents presumed to act on thrombosis, on the blood vessels, or on the disk edema itself. Others are presumed to have a neuroprotective effect. Although there have been multiple therapies attempted, most have not been adequately studied, and animal models of NAION have only recently emerged. The Ischemic Optic Neuropathy Decompression Trial, the only class I large multicenter prospective treatment trial for nonarteritic anterior ischemic optic neuropathy, found no benefit from surgical intervention. One recent large, nonrandomized controlled study suggested that oral steroids might be helpful for acute NAION. Others recently proposed interventions are intravitreal injections of steroids or anti-vascular endothelial growth factor (anti-VEGF) agents. There are no class I studies showing benefit from either medical or surgical treatments. Most of the literature on the treatment of NAION consists of retrospective or prospective case series and anecdotal case reports. Similarly, therapies aimed at secondary prevention of fellow eye involvement in NAION remain of unproven benefit.

Figure 1

A 62 year old man presented with a 3 day history of painless decreased vision in the left eye, and initial visual acuity of 20/20 on the right, and 20/40 on the left. Humphrey visual field, 24-2 SITA-FAST protocol, showed an inferior altitudinal defect in the left eye characteristic of NAION.

Figure 2

Optic nerve appearance during the acute phase (3 days after onset of decreased vision) of typical nonarteritic anterior ischemic optic neuropathy showing diffuse disc edema with peripapillary hemorrhages.

Figure 3

On fundus examination, the patient's fellow eye showed a small optic disc with cup to disc ratio of less than 0.1, the classic “disc at risk'” for nonarteritic anterior ischemic optic neuropathy.