Optic Nerve Sheath Diameter Measurement: Preliminary Findings in Ischemic Stroke Patients

Early detection of increased intracranial pressure (ICP) is critical in managing acute ischemic cerebrovascular disease (CVD) to prevent secondary brain injury. Optic nerve sheath diameter (ONSD) has emerged as a promising non-invasive surrogate marker for monitoring ICP changes.

This study aimed to evaluate the relationship between the ONSD and ICP increase in patients with ischemic CVD and its role in diagnosis. Additionally, the relationship between the right-left ONSD difference and ischemic event localization is investigated, and the diagnostic efficacy of ultrasound (USG) and magnetic resonance imaging (MRI) methods is compared.

A prospective cross-sectional study was conducted with 53 patients diagnosed with ischemic CVD and 53 healthy controls. Participants aged over 18 years were included, while those with a history of head trauma, optic neuropathy, optic nerve tumors, or additional neurological diseases were excluded. Right and left ONSD measurements were assessed using USG and MRI, and differences between the groups were analyzed.

No significant difference was found between the right and left ONSD values measured by USG in both the patient and control groups (P > 0.05). However, the absolute difference between the right and left ONSD-USG and MRI was 0.49 mm (standard deviation (SD) =0.37) in the patient group and 0.38 mm (SD = 0.23) in the control group, and this difference was found to be statistically significant (P < 0.001).

ONSD measurements may serve as an adjunctive parameter in the diagnosis and prognosis of ischemic CVD. In emergency departments, USG can be used as a rapid and reliable screening method, while MRI provides a more detailed evaluation. A right-left ONSD difference greater than 0.25 mm may be a significant marker for predicting ischemic events.