Objective: To provide transnasal endoscopic optic nerve decompression with the anatomic reference.
Method: Ten (20 sides) damp cadaveric heads of Chinese adults were cut sagittally along the midlines. The distance and angle between optic canal and anterior nasal spine were measured by ruler and protractor. Five (10 sides) damp cadaveric heads (including 2 children's) were undergone endoscopic dissection, and the optic canal and its related structure were observed.
Result: From the study of gross anatomy, the specific structure of optic canal and internal carotid artery were found. The mean length of the medial wall of optic canal was (9.12 +/- 1.89) mm. The mean diameter of the optic canal orbital aperture was (4.12 +/- 0.53) mm. The distances from the midpoint of the medial wall of optic canal orbital aperture to anterior nasal spine was (61.22 +/- 6.23) mm, and the angle from the midpoint of the medial wall of optic canal orbital aperture to anterior nasal spine was (45.3 +/- 4.5) degrees. From the study of endoscopic anatomy, optic canal, looking like a light-reflective band, was alone optic canal orbital aperture posteriorly. Obvious prominence could be found in 7 sides (70%), while not been seen clearly in 3 sides (30%).
Conclusion: The binding study of the gross and endoscopic anatomy of optic canal help us to recognize optic canal accurately under nasal endoscope, which can improve the veracity of transnasal endoscopic optic nerve decompression.