Effectiveness of Endoscopic Optic Nerve Decompression Surgery for Traumatic Optic Neuropathy with Optic Nerve Canal Fracture

Abstract

　Traumatic optic neuropathy often occurs as a complication of head and mid facial injury, and can cause permanent impairment of the visual acuity. From previous studies, optic nerve decompression surgery has been recommended for cases of traumatic optic neuropathy with optic nerve canal fracture. However, the indications for this surgery still remain controversial. Moreover, optic nerve canal fracture cannot be detected even by computed tomography (CT) in some cases. Patients diagnosed as having traumatic optic neuropathy with optic nerve canal fracture are treated by endoscopic optic nerve decompression surgery and steroid administration, by otorhinolaryngologist in collaboration with neurosurgeons and ophthalmologists at Keio University Hospital. Six patients were treated between May 2015 and May 2017. They ranged in age from 17 to 78 years old, and the intervals from injury to surgery ranged from 19 hours to 6 days. Five patients had injury of the outer half of the eyebrows. Preoperative CT revealed optic canal fracture in only 3 cases, whereas intraoperatively, all 6 cases were detected to have fracture. Preoperative visual acuity was hand motion or better in 4 patients, and no light perception in 2 patients. The visual acuity improved postoperatively in 5 patients. No improvement was observed in the patient who underwent surgery 6 days after the injury. Blunt injury on the outer half of the eyebrow was a useful clue for the diagnosis of optic nerve canal fracture, especially in cases where it could not be detected by CT. In cases of traumatic optic neuropathy with optic nerve canal fracture, early decompression of the optic canal and steroid administration play a key role in the recovery of the visual acuity.