Transnasal Endoscopic Optic Nerve Decompression

Introduction: Injury to the optic nerve from compressive lesions can result in devastating visual loss. Several surgical approaches for decompression of the optic nerve have been described. A transnasal transsphenoidal endoscopic approach is a minimally invasive and effective route for intracanalicular optic nerve decompression. Methods: Transnasal transsphenoidal endoscopic intracanalicular optic nerve decompression was performed on four fixed cadaveric specimens (8 nerves). The decompression was assessed by direct visualization and CT measurement of the length and degree of optic nerve decompression. The anatomic study is complemented by details from a clinical case. Results: Based on sinus CT imaging, the medial 97.2° of the intracanalicular optic nerve was decompressed 1.21 mm in fixed cadaveric specimens. Anatomically, the decompression extended from the annulus of Zinn to the posterior lateral wall of the sphenoid bone. Conclusion: The transnasal endoscopic route is an effective approach for decompression of the medial portion of the intracanalicular optic nerve in the setting of compressive pathology. Limits to this technique include the location of the compressive pathology and anatomic characteristics of the optic canal, including medial length and exposure to the sphenoid sinus.