This randomized double-masked clinical trial evaluated the efficacy of oral steroid therapy for the treatment of acute nonarteritic anterior ischemic optic neuropathy (NAION).
Thirty-eight patients with acute nondiabetic NAION were randomized to placebo (19 patients) or to oral prednisone starting with a 80-mg dose for 2 weeks followed by a slow taper (19 patients). Investigators evaluated BCVA, visual evoked response (VER) and OCT scans at 6 months after treatment.
Both groups had significant improvement in BCVA at 6 months, with the steroid group showing a larger improvement (P=0.02). However, there were no differences in the final BCVA between groups.
Prednisone led to faster resolution of optic disc edema, but final OCT measurements were similar between groups. The steroid group had a larger percentage of VER latency improvement.
Only 25 of 38 patients were treated within 2 weeks of the onset of symptoms. When analyzing the patients who were treated within 2 weeks, the final median visual acuity was the same between groups, but the prednisone-treated group trended toward less severe vision loss (range 0.3–1.77 logMAR for the prednisone group versus 0.6–2.7 logMAR for the placebo group; P=0.06). Therefore, a larger sample size of patients treated within 2 weeks may have revealed a statistically significant improvement.
Another limitation is the lack of visual fields data. Lastly, only non-diabetic patients were included; therefore, a quarter of patients presenting with acute NAION during the study period were excluded.
Overall, I applaud this study because it is the first randomized double-masked study to examine the efficacy of prednisone for NAION. At first glance, it appears to be the final nail in the coffin showing that prednisone is not helpful in patients with acute NAION as there was no significant difference in the final visual acuity.
However, the prednisone-treated group had a larger percentage improvement in visual acuity and VER compared with the placebo group, despite the fact that only 66% of patients were treated within 2 weeks of symptom onset. Whether this translates to a clinically significant improvement is unclear and remains open to debate.
I personally don’t think prednisone is a wonder drug for NAION but have sometimes used it in the past for an eye with poor vision from NAION, especially the second eye. We don’t currently have any other good options. A new drug could be on the horizon, however, with an intravitreal drug by Quark Pharmaceuticals (QPI-1007), which is a siRNA caspase 2 inhibitor. There is an ongoing phase 2/3 multicenter randomized, double-masked, sham-controlled trial (NCT02341560) (Neuro-Ophthalmology Research Disease Investigator Consortium (NORDIC) co-sponsored), which is expected to conclude in 2020.