Methanol poisoning is a serious problem in part of developing world. optic neuropathy is the most serious toxic effect that leads to ganglion cell atrophy, severe optic neuropathy and finally permanent and irreversible optic atrophy and visual loss. Erythropoietin (EPO) has emerged as a potential candidate drug for neuroprotection/neuroregeneration. We recently reported that EPO was effective in methanol associated/traumatic optic neuropathy. We undertook a randomized placebo-controlled clinical trial to assess the effect of EPO on visual outcome following methanol-associated optic neuropathy and report the interim analysis.

The study was designed as a mutil-center randomized placebo-controlled clinical trial with two parallel arms conducted at the Farabi Eye Hospital from March 2015 to December 2018. The primary outcome measure was the mean change in best corrected visual acuity (BCVA) in both eyes at 16-week follow-up. Subjects were eligible if they were presented with confirmed methanol associated optic neuropathy, BCVA <20/30 and less than 3 weeks since methanol ingestion. Participants were randomized to receive either erythropoietin, 20,000 IU in 100 mL normal saline or placebo (100 ml 0.9% saline) in 2 hours for 3 successive days. A total of 34 eligible eyes were randomized and included in the intention-to-treat analysis, 20 in the EPO group and 14 in the placebo group.

Patients in EPO group had an improvement of 1.52 logMAR (p<0.001), while the placebo group had an improvement of 0.49 logMAR (P < .09). Eighty-five percent of the eyes in the EPO group versus 43% in the placebo group had vision improvement ≤ -0.2 logMAR (Percent difference 42%, CI (10-65%) p=0.01). The final mean of BCVA at 16 weeks follow-up was 1.84 logMAR in the EPO group and 2.79 logMAR in the Placebo group. The mean difference in final BCVA between groups was 0.95 logMAR (95% confidence interval: 0.23-1.74, P=0.012).

Intravenous erythropoietin could improve the visual acuity in patients with established optic neuropathy following methanol intoxication. We suggest that intravenous EPO to be considered as part of the standard treatment regimen for patients with methanol optic neuropathy.