Abstract：Objective To investigate the effect of decompression of optic nerve canal for traumatic optic neuropathy (TON) via lateral supraorbital approach. Methods A retrospective case series study was performed to analyze clinical data of 23 TON patients admitted to First Peoples Hospital of Huzhou from December 2013 to June 2019. There were 16 males and 7 females, aged 17-51 years ［(34.3±2.2)years］. Degree of visual impairment included count fingers in 4 patients, hand motion in 4, light perception in 9 and loss of light perception in 6. Visual evoked potential examination (VEP) was performed in 15 patients before surgery. The amplitude of P100 completely disappeared in 5 patients, and the amplitude of P100 was lower than the lower limit of normal value and the latency prolonged in 10 patients. The time from injury to operation was 3 h-14 days ［(3.3±0.6)days］. All patients underwent decompression of optic nerve canal via supralateral orbital approach, and dural repair was performed simultaneously in 11 patients with dural rupture. Intraoperative fractures and meningeal tears, duration of operation, blood loss, and hospitalization duration were recorded. Combined with the classical visual acuity improvement assessment method and the World Health Organization (WHO) low vision and blind grading standard, visual acuity was compared before operation, at 10 days and 3 months after operation. Glasgow Coma Scale (GCS) was used to evaluate patients state of consciousness in the course of the disease. Glasgow Outcome Scale (GOS) was used to evaluate the prognosis. Incidence of complications was observed as well. Results All patients were followed up for 12-16 weeks ［(13.5±2.4)weeks］. Intraoperative microscopic exploration revealed that all patients had optic nerve canal fracture, 3 patients had frontal fracture with dural rupture, and 8 patients had ethmoid bone fragment with anterior skull base dural rupture. The duration of operation was 108.5-224.3 minutes ［(151.8±30.2)minutes］, including (32.5±8.4)minutes for craniotomy. The intraoperative blood loss was 90.5-165.3 ml ［(121.3±15.5)ml］.The hospitalization was 14-26 days ［(19.7±3.4)days］.The visual acuity of 13 patients (57%) improved and 5 patients (39%) relieved from blindness 10 days after operation, showing significant difference compared with the preoperation (P<0.05). The visual acuity of 17 patients (74%) improved and 9 patients (39%) relieved from blindness at 3 months after operation. There was significant difference in visual acuity examined between 10 days and 3 months after operation (P<0.05).Six patients were invalid, and 4 of them had no light perception before operation and the amplitude of VEP examination completely disappeared. All patients had GCS of 15 when left the hospital and GOS of 5 at 3 months after operation. One patient had cerebrospinal fluid rhinorrhea and healed after 7 days of supine position. No secondary hematoma, epilepsy or intracranial infection occurred during follow-up. Conclusion Optic canal decompression via the lateral supraorbital approach can improve visual acuity in early stage and increase the rate of out of blindness, with low postoperative complications and satisfactory functional recovery, which is worthy of clinical application.
