Variation of Optic Nerve Types in Different Age Quartiles on Two Sides Based on Delano's Classification of Optic Nerve using Computerized Tomography: A Single Center Cross-Sectional Study in Karachi

Abstract

Objective: To understand the anatomy of the sphenoid sinus and its associated structures, especially the
variations of the optic nerve, to avoid any surgical trauma.
Study Design: Cross-sectional study.
Place and Duration of Study: The study was conducted at the Radiology Department, Ziauddin University,
Karachi, Pakistan from January 2017 to May 2017.
Methods: During the study, 270 participants were assessed after ruling out any sphenoid sinus (SS) abnormality
or any abnormality involving adjacent structures. The scans were performed using a Toshiba Alexion 16-slice CT
scanner. Delano's classification was used to classify the optic nerve into different types according to the
relationship between the optic nerve and the posterior paranasal sinuses. Data was analyzed on SPSS version
26. Frequencies and percentages were recorded for categorical variables. Mean and standard deviation were
reported for the continuous variables.
Result: According to the age quartiles, no significant difference was found in the distribution of classes of
different types of optic nerve according to Delano's classification on both the right and the left sides—also, Type
I optic nerve was the most frequent type bilaterally. However, there was a considerable difference in the
frequency of optic nerve occurrence on the left and right sides.
Conclusion: The preoperative analysis of optic nerve classification is necessary, and knowledge of anatomical
variations is imperative so that endoscopic sinus surgery may be planned accordingly to avoid any iatrogenic
injuries during functional endoscopic sinus surgery (FESS).

How to cite this: Lakhani M, Raza I, Mukhtar S, Sadiq M, Azwar S, Hassan N. Variation of Optic Nerve Types in Different Age Quartiles on Two Sides Based on Delano's Classification of Optic Nerve using Computerized Tomography: A Single Center Cross-Sectional Study in Karachi. Life and Science. 2025; 6(2): 190-195. doi: http://doi.org/10.37185/LnS.1.1.687