Traumatic optic neuropathy treatment trial (TONTT): open label, phase 3, multicenter, semi-experimental trial

Intravenously administered erythropoietin (EPO) was firstly commenced (phase 1) in patients with indirect traumatic optic neuropathy (TON) by this group in 2011. It was re-tested by another group (phase 2) in 2014. This multicenter clinical trial was designed to compare its effect with intravenous steroid and observation.

Included were TON patients ≥5 years of age and with trauma-treatment interval of ≤3 weeks. Follow-up visits were set at 1, 2, 3, 7, 14, 30, and at least 90 days after treatment. EPO and methylprednisolone were infused intravenously every day for three consecutive days. Primary outcome measure was change in the best corrected visual acuity (BCVA). Secondary outcomes included change in color vision and relative afferent pupillary defect (RAPD), side effects, and factors affecting the final visual improvement.

Out of 120 patients, 100 (EPO: 69, steroid: 15, observation: 16) were finally included. All three groups showed a significant improvement of BCVA which was not significantly different between the groups (adjusted for pretreatment BCVA). Color vision was significantly improved in the EPO group. Late treatment (>3 days) (odds ratio = 2.53) and initial BCVA of NLP (odds ratio = 5.74) significantly worsened visual recovery. No side effect was observed in any group.

EPO, steroid, and observation showed a significant improvement of BCVA in patients with TON. Initial BCVA of NLP and late treatment (>3 days) were significant risk factors for visual improvement.