Microanatomical Study on Optic Canal

Objective To provide the anatomical data for optic canal decompression. Methods By anatomical method, the optic canal opening, walls and their syntopy were observed on 67 adult cadaverical heads and 100 dry skulls.Results The optic canal consists of lesser wing and body of sphenoid bone, courses from internoposterior to externoanterior side. There were four walls and two openings for optic canal. The length of the wall of canal was 10.70±0.23mm, 6.25±0.18mm,9.67±0.18mm,and 7.91±0.17mm in superior, inferior, internal and external walls respectively. The optic canal protrudes into ethmoidal and sphenoid sinuses. The dura and ophthalmic arterial impressions could be found on cranial opening and inferior part of optic nerve. Conclusion The position of the optic canal could be affirmed by optic canal bulge. The inferior wall and medial wall of optic canal was close to optic nerve, ophthalmic artery, internal carotid artery. The neighbouring structures of optic canal were protected while the inferior wall was incised.