Background: There are significant discrepancies in the optic nerve sheath diameter (ONSD) reported in the literature. We aimed to determine the ultrasonographic imaging features of ONSD and ophthalmic vessels in a healthy population, using a standardized protocol, and to estimate the effect of demographics and positioning changes on imaging measurements.
Methods: We measured the mean values of the ONSD in supine and sitting position and the Doppler imaging parameters of the ophthalmic, central retinal and short posterior ciliary arteries.