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 disc 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 (IONDT), the only class I large multicenter prospective treatment trial for NAION, 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.

Subretinal fluid is common in experimental non-arteritic anterior ischemic optic neuropathy

“…Rarely, human AION is treated with anti-VEGF or steroids. 17,18 Certainly, ischemia could lead to the upregulation of VEGF and perhaps contribute to the formation of subretinal fluid. However, anti-VEGF therapy has been associated with exacerbation of retinal ischemia.…”

Nonarteritic Anterior Ischemic Optic Neuropathy: An Update on Demographics, Clinical Presentation, Pathophysiology, Animal Models, Prognosis, and Treatment

“…A large non-randomized study revealed that patients with optic disc edema from acute NAION who received oral prednisone initiated at a dose of 80 milligrams daily for 2 weeks with a taper had improved visual outcomes compared with untreated controls [62]. Because of the limitations of the study design and potential biases in the two populations studied, these results must be interpreted with caution [7]. Indeed, the controversies surrounding the use of corticosteroids in NAION stem mainly from a lack of Class I evidence supporting the efficacy of the intervention, as well as the potential risks of the intervention [63].…”

“…There is no sex predilection for NAION. With respect to race, whites appear to be more likely to develop the condition than minority populations [5,6], possibly due to risk factors associated with optic disc morphology [7,8].…”

“…With regards to acute NAION, a recent extensive review concluded that treatments aimed at preventing thrombosis, promoting vasodilation, reducing optic disc edema, and limiting axonal or neuronal injury have either proven unsuccessful or are lacking in scientific evidence [7]. Three of the treatments studied previously, however, are important to note.…”

“…The disc edema in NAION typically resolves within 4 to 6 weeks, and is replaced by sectoral or diffuse pallor ( Figure 2). A common feature in patients with NAION is a physiologically small cup to disc ratio in the contralateral eye, on the order of 0.3 or less, known as a "disc at risk" ( Figure 3) [2,7,13].…”