Optic canal: a CT-based morphometric study in north Indian population

Abstract

Background

Lesser wing of sphenoid joins the body of sphenoid by two roots which are separated by the optic canal. Optic canal is a communicating channel between orbit and middle cranial fossa, forming a passage for the ophthalmic artery and optic nerve. Considering the delicate neurovascular structure that traverses the narrow confines of the optic canal, knowledge of the morphometry, anatomical variations of this canal and their relations becomes an important part of diagnostic medicine and surgical management.

Objective

The aim of the study was to conduct morphometric analysis and document variations of optic canal in north Indian population and study its sexual dimorphism.

Material and Method

Type of Study Cross-sectional study. Sample size 200 Computerized tomography head axial section scans from picture archiving and communication system. The computer-assisted measurements of optic canal parameters were obtained on both right and left sides. Statistical analysis Unpaired t-test, paired t-test and ANOVA were applied.

Result

Optic canal of 110 males, 90 females were examined. The overall cranial opening diameter, orbital opening diameter and length of optic canal in males were 4.34 ± 0.74, 3.17 ± 0.58 and 9.81 ± 1.62 and in females they were 3.99 ± 0.71, 2.97 ± 0.59 and 9.38 ± 2.02 respectively.

Conclusion

Significant gender difference is seen in cranial and orbital opening diameter, and distance from midsagittal plane. No statistical significant difference is observed in right and left side parameters. A thorough knowledge of the normal dimensions of optic canal is important for evaluation and management of cases of optic nerve decompression.