Determination of normal values of optic nerve sheath diameter in Turkish adult population using magnetic resonance imaging

Abstract

The measurement of optic nerve sheath diameter (ONSD) is a reliable tool for the estimation of increased intracranial pressure (ICP). However, it is known that racial changes can occur in human anatomy. In the present study we aimed to determine the normal values of ONSD in Turkish adult population. This retrospective study involved the collection of data between June 1, 2015, and May 31, 2019, and was conducted on 291 adults known to have no increased cranial/intraocular pressure. The ONSD was measured at 3 mm posterior to the globe on MR images. 291 subjects were enrolled, 63.6% of whom were female. The total median ONSD was 4.40mm (4.20- 4.70). The median ONSD of the male participants was 4.50mm (4.25-4.75), of the female participants was 4.35mm (4.15-4.50) and the difference was statistically significant (p = 0.001). According to statistical analysis, it was found that only the presence of chronic renal failure altered the median of ONSD among the comorbid diseases (p = 0.042). Monitoring and treating increased ICP is crucial. Thanks to an ONSD with a known normal value, recognition and emergency management of this pathology would be easier. We think our study is noteworthy because it is the first study investigating the normal ONSD value in Turkish adult population.