Importance of Preoperative Pupillary Reflex in Traumatic Optic Neuropathy

Traumatic optic neuropathy (TON) refers to a pathological condition caused by direct or indirect injury to the optic nerves. In the case of patients with traumatic brain injury, adequate vision evaluation is difficult in many cases due to altered mentality. In order to address this problem, we investigated preoperative pupillary light reflex in TON patients as a predictive factor of surgical outcomes after optic nerve decompression.

From April 2020 to September 2022, we enrolled patients who were diagnosed with TON and underwent endoscopic optic nerve decompression at our institution. Vision and pupil reflex tests were performed by an ophthalmologist before and after surgery.

Seven patients were enrolled. Their ages ranged from 9 to 78 years and all were male. Among the seven patients, the patient whose pupillary light reflex was sluggish with 6 mm-sized pupil and absent with 7 mm-sized pupil before surgery showed no improvement in vision. Patients with some response to direct reflex or contralateral indirect reflex testing preoperative showed vision improvement after operation.

Direct and indirect pupillary reflexes can be important factors determining treatment outcome for TON. In unconscious patients with a fracture involving the optic canal, timely surgical intervention based on pupillary reflex can prevent permanent loss of vision.