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

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SUDARSHANA SMITA

Keywords

duplicated optic canal, optic nerve, ophthalmic artery, skull bone.

Abstract

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.


 

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References

1. Standring S. Gray’s Anatomy. 39th ed. London: Churchill Livingstone; 2005. p. 688-700.
2. White LE. An anatomic and X-ray study of the optic canal. Beston Med Surg J 1942; 189:741-8.
3. Manfredi SJ, Raji MR, Sprinkle PM, et al. Computer- ized tomographic scan findings in facial fractures as- sociated with blindness. Plast Reconstr Surg 1981;68: 479 –90.
4. Custer PL. Optic nerve sheath decompression. Eur J Implant Ref Surg 1993;5:113–4.
5. Sofferman RA. The recovery potential of the optic nerve sheath decompression. Ophtalmology 1997; 100:683–90.
6. Sofferman RA. Transnasal approach to optic nerve decompression. Oper Tech Otolaryngol Head Neck Surg 1991;2(3):150 –6.
7. Ghai R, Sinha P, Rajguru J, Jain S, Singla M. Duplication of optic canal in human skull. J Anat Soc India 2012;61(1):33-6
8. Sweta VR, Kumar SS. Accessory optic canal in South Indian dry skull. J Pharm Sci Res 2014;6(5):224-5.
9. Patil GV, Kolagi S, Padmavathi G, Rairam GB. The duplication of the optic canals in human skulls. J Clin Diagn Res 2011;5(3):536-7.
10. Singh M. Duplication of optic canal in adult Japanese human skulls. J Anat Soc India 2005;54(2):1-9.
11. Shinde VS, Patil R, Channabasanagouda, Mallikarjun M. Study of duplication of optic canal in hundred dry human skull bones. Int J Biomed Res 2013;04(11):633-5
12. Choudhry R, Choudhry S, Anand C. Duplication of optic canals in human skulls. J Anat 1988;159:113-6.
13. Nayak et. al. Asian J Pharm Clin Res, Vol 9, Suppl. 3, 2016, 85-86
14. Calori, L, (1891). Su varie particolarita osteologiche della base del crania umano. Mem. R. Acad.Bologna (Ser. V), 2,85-109
15. Le-Double AF. Traite’des Variations des Os Du Crane de I’. Homme Paris: Vigol Fre’res. 1935; 1903. p. 372.
16. Leon KE. Embryology of normal optic canal and its anomalies - An anatomic and roentgenographic study. Investigative Radiology. 1996; 1 (5): 346-362.
17. Scheuer L, Black S, Christie A. Developmental Juvenile Osteology in Head Neck And Dentition, Elsevier 2000 pp 90
18. Augier M (1931). Sequelette cephalique, in Poirier and Charpy;s Traite d' Anatomie Humaine, Paris : Masson et Cie. Vol. I, pp. 234, 246 and 248, new ed.
19. Keyes JEL. Observations on four thousand optic foramina. Albrecht V. Graefes Archiv fur opthalmologie 1935; 13, 538-568