Morphometric Analysis of the Optic Strut in Adult Human Dry Skulls: An Anatomical Study with Surgical Implications

Background: The optic strut is a small but anatomical important bone structure that joins lesser wing of the sphenoid to body of the sphenoid and forms the lower border of the optic canal. The optic strut is in close proximity to the optic nerve, the internal carotid artery and cavernous sinus and is therefore critical for safe surgical navigation of skull-base surgery and thus essential for precise morphometric knowledge. The morphometric data of optic strut in human population is so far limited to Indian population. The aim is to describe and analyse the morphometry of the optic strut in dry skulls of adult human remains and assess the clinical importance of this structure. Material and Methods: 30 adult dry human skulls were obtained from the Department of Anatomy, Sawai Man Singh Medical College, Jaipur and a descriptive cross-sectional study was carried out on them. Optic strut anteroposterior (AP) and transverse diameters were bilaterally measured with a digital Vernier calipers and bisector. The measurements are all in millimetres (mm). Mean ± standard deviation (SD) was used to express descriptive statistics; and the paired Student's t-test was used for bilateral comparison. The p value was used as a threshold for significance at < 0.05. Results: The mean anteroposterior diameter of the optic strut was 5.70 ± 6.68 mm on the right and 6.22 ± 7.51 mm on the left, while the mean transverse diameter measured 6.76 ± 6.65 mm on the right and 7.44 ± 7.39 mm on the left. The left optic strut demonstrated larger mean dimensions than the right, indicating a trend toward left-sided dominance. The findings also revealed considerable inter-individual variability in optic strut morphology. Conclusion: The present study demonstrates significant morphometric variability of the optic strut in the Rajasthan population, with relatively larger dimensions on the left side. These findings provide valuable population-specific anatomical reference data that may facilitate pre-operative planning, improve radiological interpretation, and enhance the safety of anterior clinoidectomy, optic nerve decompression, and other skull-base surgical procedures.

Keywords: Optic Strut, Morphometry, Optic Canal, Sphenoid Bone, Skull Base, Anterior Clinoidectomy, Dry Human Skull, Neurosurgery.