Optic Nerve Sheath Diameter Assessment in Patients with Intracranial Pressure Monitoring

Abstract

BackgroundOptic nerve sheath diameter (ONSD) has been found to have good correlation with intracranial pressure (ICP) measurements. Here, we aim to determine if the correlation between ONSD and ICP persists throughout the acute phase of neurologic injury through the evaluation of patients with ICP monitoring. We also aim to determine if the ONSD assessments at different depths (3, 6, or 9 mm) and a ratio of the ONSD and eyeball transverse diameter (ETD) are better correlated with ICP than the well-studied ONSD assessment at 3 mm beyond the globe. MethodsThis retrospective study included 68 patients more than 18 years of age with ICP monitors with both traumatic and spontaneous intracranial injuries. Head computed tomography (CT) scans were reviewed by a radiology resident for assessment of the ETD and ONSD at depths of 3, 6 and 9 mm beyond the globe, and the readings were confirmed by a neuroradiologist. The mean ICP recordings two hours before and after a CT scan were used for assessing the correlation.ResultsWe found that ONSD expansions during the acute phase of neurologic injury were seen even without ICP elevations. This lack of correlation persisted even when different depths of the ONSD assessment or ONSD/ETD ratios were studied.ConclusionThis study suggests that ONSD assessment throughout the acute phase may not be a reliable method to monitor ICP. ONSD expansion can persist even after ICP control, and this may be the reason for ONSD expansions seen in our study even with normal ICPs. Further larger size studies are needed to confirm these findings.

The clinical and prognostic values of optic nerve sheath diameter and optic nerve sheath diameter/eyeball transverse diameter ratio in comatose patients with supratentorial lesions

“…Conversely, the ONSD/ETD ratio was first described in 2014 and seemed to be more accurate in predicting ICP than ONSD alone [ 8 , 9 ]. A number of scholars have demonstrated that ONSD increases with the elevation of ICP, and increased ICP is strongly correlated with the poor prognosis of patients with neurological disorders [ 7 , 10 – 12 ]. It was found that ONSD was increased in 95% of patients with ICH or SAH, as indicated by CT, and ONSD was 6.6 ± 0.8 mm with a cut-off value of 5.5 mm, suggesting an elevated ICP [ 5 ].…”

Clinical Value of Optic Nerve Sheath Diameter Assessment in Prognosis of Comatose Patients with Supratentorial Lesions

“…As a noninvasive monitoring method of ICP, ONSD has been used for 20 years and expected to be an effective technique to predict the prognosis of patients. Some researches suggest that ONSD increases with the increase of intracranial pressure, and the increase of ICP has a signi cant correlation with the poor prognosis of neurological function [7,[10][11][12]. It was found that ONSD increased in 95% of patients with CT indicated ICH or SAH, and the pathological ONSD was 6.6 ± 0.8 mm, ONSD/ETD ratio was 0.29 ± 0.05 against normative 0.19 ± 0.02.…”

Application of interventional ultrasound in emergency medicine conditions

“…There are different methods of performing this test, but I think that the most accurate fIgUre 12. Aorta width measurement and the fastest method is the 3-point compression method [43].…”