Traumatic optic neuropathy (TON) usually occurs after maxillofacial and head trauma and is a comorbidity of blunt head or maxillofacial trauma [1], and early surgical decompression is one of the main methods for the treatment of TON. The endoscopic septopalpebral sinus approach for optic nerve canal decompression has been developed in recent years with the rise of nasal endoscopic technology and nasal-ocular related surgery, and has received much attention from scholars at home and abroad because of its better clinical results. 1, TON pathogenesis TON pathogenesis can be divided into two kinds: direct injury and indirect injury. The mechanism of direct optic nerve injury is the direct trauma or rupture of the optic nerve caused by the fracture of the optic nerve canal, which is manifested by the loss of vision at the time of trauma or within a short period of time, and the vision can hardly be recovered after this direct injury. The mechanism of indirect optic nerve injury is still inconclusive, and possible explanations include intra-optic nerve edema, hematoma, microvascular injury in the optic nerve sheath, altered cerebrospinal fluid circulation, interruption of direct axoplasmic transport, and reduction in the number of nerve axons. Indirect injury is characterized by varying degrees of visual changes, including reduced visual acuity, partial visual field defects, and changes in visual evoked potentials, etc. Early in the injury, the patient’s visual acuity may also not change, and only the ophthalmologic examination shows MarcusGunn’s pupillary changes. 2, the treatment of TON There is still a great controversy about the treatment of TON because the mechanism of optic nerve injury and repair is not clear [2]. The main treatment methods are hormone therapy, optic canal decompression, and hormone therapy plus optic canal decompression. Although there are many reports in the literature on the treatment of TON, it is not clear who is the best treatment option when reporting various treatment methods and outcomes, whether hormonal therapy, surgical therapy, or hormonal plus surgical therapy. However, most scholars have recognized that optic canal decompression is an effective remedial treatment for those patients with TON for whom hormonal therapy is ineffective [3, 10]. From the analysis of numerous literatures, the treatment outcomes of the above mentioned 3 treatments may not differ statistically and significantly. And the biggest controversies among the literature are shown in the degree of injury to TON before surgery, the optimal time of treatment, the evaluation of the results before and after treatment, and the tendency of TON to heal itself [4]. 3. Optic nerve canal decompression There are various surgical approaches for optic nerve canal decompression. The advantages and disadvantages of the various approaches are briefly outlined. 3.1, transcranial optic nerve canal decompression, this surgical approach is commonly used in neurosurgery, the advantages of which are a wide range of surgical operations, an open field of vision, the possibility of simultaneous repair of anterior skull base fractures, exploration of the saddle area, incision of the falciform folds of the embedded optic nerve and the implementation of intracranial hematoma removal [5]. The disadvantages are large trauma, insufficient decompression, many surgical complications, patient concerns about surgery, and high cost. 3.2, Intraorbital approach optic canal decompression, this surgical approach is commonly used in ophthalmology, the advantages are short approach, clear view with the help of microscope, can adapt to anatomical variation, the disadvantages are small view, poor exposure, difficult to complete the whole optic canal decompression. 3.3. External nasal decompression of the optic nerve canal through the sieve and pterygoid sinus, commonly used by ophthalmologists or otorhinolaryngologists, the advantages of this procedure are small trauma and less bleeding, the disadvantages are long surgical path, anatomical landmarks are not easy to grasp, the field of view is restricted, the operation is difficult, and the facial scar remains. 3.4, nasal endoscopic optic nerve canal decompression (EOND), with the development of nasal endoscopic surgery and its application in related disciplines, EOND has been repeatedly reported in the domestic and foreign literature in recent years. 34 cases of EOND were reported by Kountakis et al [3], 23 cases had no improvement in visual acuity after high-dose hormone therapy, 17 of which underwent EOND and 14 cases had improvement in visual acuity after surgery. Eleven of the 17 operated patients had imaging or intraoperative confirmation of optic nerve canal fracture, of which 10 had improved visual acuity after surgery and 6 had no clear evidence of fracture, and 4 had improved visual acuity after surgery. The literature points out that the advantages of ENOD are clear surgical field, small trauma, fast recovery, no facial incision, aesthetic, olfactory protection, and safety. For the current situation in which the efficacy of various treatments cannot be significantly superior, it is wise to choose a less invasive, safe and less complicated procedure, so EOND has a broad application prospect. 4.Anatomy of the optic nerve canal under nasal endoscopy 4.1.Anatomical characteristics of the optic nerve canal, the entire length of the optic nerve is 45 mm～50 mm, divided into four parts: intracranial section, intracanalical section, intraorbital section and intrabulbar section. Traumatic optic neuropathy can occur in any segment of the optic nerve, but the intracanalicular segment is the most common. Injuries to the orbital and intracranial segments generally heal better than the canal segment because the pressure is easily relieved, whereas injuries to the canal segment of the optic nerve are surrounded by hard tissue and the pressure generated by tissue swelling cannot be relieved [6], which can cause secondary damage to the optic nerve fibers, making early surgical decompression of canal segment optic nerve injuries necessary. The pathological basis for the visual impairment due to traumatic optic neuropathy is the compression of the optic nerve by peri-optic canal fracture fragments, posterior septal sinus fracture fragments, orbital apical hematoma, etc. The swollen optic nerve is compressed by the optic canal after trauma, and these factors may lead to nerve dissection, axonal rupture, contusion, dysfunction of optic nerve axoplasm transport, retrograde collapse of retinal ganglion cells, blood supply to the optic nerve nutrient vessels The optic nerve canal rupture, axonal fracture, contusion, optic nerve axoplasmic transport dysfunction, retinal ganglion cell retrograde collapse, optic nerve trophic blood supply, and damage to the blood supply system [7]. 4.2, the significance of the optic canal rongeur for optic nerve decompression, the optic canal rongeur is a bulge of the optic canal formed on the lateral wall of the pterygoid or septal sinus into the sinus cavity, and is an important anatomical landmark for finding the optic canal during nasal endoscopic optic nerve decompression. vanaAlyea (1941) observed that 40% of specimens had an optic canal rongeur [8], the optic canal rongeur and the internal carotid artery convexity are close to each other, both The optic canal ramus and the internal carotid artery convexity are close to each other, both of which project into the sinus cavity in a forward-opening figure-of-eight shape, with the presence of the subpterygoid root fossa between them. Therefore, in the absence of the optic canal bulge, we can confirm the optic canal by using the internal carotid artery bulge and the posterior root fossa of the pterygoid as markers. Therefore, confirmation of the optic canal should be based on the basic location and anatomical landmarks. 5, EOND indications and contraindications The treatment of traumatic optic nerve injury has always been a multidisciplinary concern. So far, the main treatment methods are high-dose adrenocorticotropic hormone and various accesses for optic canal decompression. Usually, immediate post-injury blindness is often indicative of severe optic nerve injury, the presence of partial or total rupture, and the treatment effect is more poor; while for those who have some residual visual acuity after injury or gradual loss of visual acuity after injury, it is generally possible that the optic nerve is compressed by optic nerve edema, fracture fragments or peri-optic nerve and intrathecal hematoma, at which time optic nerve canal decompression should be performed in a timely manner to release the compression of the optic nerve, and generally a better outcome can be obtained. Luxenberger et al [9] reported that internal treatment includes the first intravenous methylprednisolone (30 mg/kg), 5.5 mg/h maintenance for 36 h to 48 h. The patient’s visual acuity is tested regularly, and if there is no sign of improvement, surgical treatment is performed if conditions permit; if there are signs of improvement in visual acuity after internal treatment, the hormone dosage should be maintained; if the visual acuity and visual field continue to deteriorate under the hormone maintenance amount, surgical treatment is performed; the injury is treated with surgery. Thakar et al [10] reported that in 35 cases of delayed TON, there was no improvement in visual acuity after hormone therapy. Of the 35 cases with delayed TON, 20 had no improvement in visual acuity after hormone therapy and underwent surgery, 19 of which had improved visual acuity, and the improvement in visual acuity was 1 week to 2 months after surgery. It is stated in the article that the time of surgery should be within 2 weeks after the injury. However, the surgery was basically ineffective for those who were blinded immediately after the injury and had been treated with hormone therapy for more than 2 weeks. The surgery is contraindicated in cases of severe cranial trauma, unconsciousness, unstable vital signs, and inability to tolerate general anesthesia; complete loss of vision and loss of pupillary light reflex immediately after injury; complete severance of optic nerve and optic cross; and optic nerve atrophy more than 1 month after injury. 6, EOND treatment effect From the viewpoint of surgical method selection, the current literature reports are mostly limited to the evaluation of the superiority of EOND surgery, such as microtrauma, more detailed operation, safer, etc., as for the evaluation of the results of the surgery has yet to be concluded after more and more extensive EOND. ～The visual acuity improved in 7 cases. Shi Jianbo et al [11] reported 14 cases of EOND, and 9 cases were effective, with an operative time of (5.91±5.32) d after injury.