Although many treatments have been tried, there remain no proven effective therapies to treat nonarteritic anterior ischemic optic neuropathy.
Chicago-Although many treatments have been tried, there remain no proven effective therapies to treat nonarteritic anterior ischemic optic neuropathy (NAION), according to Andrew G. Lee, MD. In addition, there have been no randomized clinical trials for medical treatment as in optic neuritis.
Dr. Lee described the minimal information that is available in the literature during the annual meeting of the American Academy of Ophthalmology.
In the case under discussion, a 64-year-old man lost vision in the left eye 4 years previously as a result of a "stroke" of the optic nerve. Six days before presentation, the patient awoke with painless inferior visual field loss in the fellow eye that then progressed and involved the superior visual field. The visual acuity was 20/400 in the right eye and 20/80 in the left eye. Both pupils were sluggish; there was a mild relative afferent pupillary defect in the right eye. The fundus of the left eye was atrophic in the superior half and fundus of the right eye had disc edema. The left eye had arcuate defects and the right eye had an inferior defect that progressed superiorly. Magnetic resonance imaging (MRI) showed normal optic nerves.
"Although multiple therapies for NAION have been attempted, most have not been adequately studied," Dr. Lee said. "There is an animal model of NAION that is being explored currently. The Ischemic Optic Neuropathy Decompression Trial showed there was no benefit of surgery for NAION."
No class 1 treatment trials of NAION have been undertaken, and most of what evidence is available is in the form of case reports of the effects of intravitreal steroids and anti-vascular endothelial growth factor drugs.
"These case reports do not provide proof of efficacy," he said. "They can be used to generate hypotheses but not for hypothesis testing."