STUDY OF DUPLICATION OF THE OPTIC CANAL IN DRY HUMAN SKULL BONES: AN OSTEOLOGICAL STUDY

Introduction: The optic canal is medially located, one of the two round openings at the apex of a pyramidal-shaped orbit connecting the orbit with the middle cranial fossa, housing the optic nerve and ophthalmic artery. A duplicated optic canal is a rare variation. Objective: To study the presence of unilateral or bilateral duplication of the optic canals and complete or partial duplication in human skull bones. Material and method: A descriptive cross-sectional study was conducted on 50 dry human skull bones collected from Bhagwan Mahavir Institute of Medical Sciences, Pawapuri, Nalanda, Bihar, and ESIC Medical College, Bihta, Patna, from February 2023 to September 2024. Each skull was meticulously examined for the duplicated optic canal: partial or complete, unilateral or bilateral. Results: A completely duplicated optic canal was found in only one human dry skull bone on the left side. A keyhole anomaly of the optic canal in the same skull bone on the right side was also found. In addition, one partially duplicated optic canal was observed in another skull bone on both the left and right sides. Conclusion: This study provides further insights into the rare variation of the optic canal and highlights the fact that even though duplication of the optic canal is a rare finding, it has immense clinical significance, especially during surgical exploration of the orbit, access to the cavernous sinus, Sella tursica, and decompression of the optic nerve.