Utility of Optic Nerve Sheath Diameter Measured by Ultrasonography for the Detection of Increased Intracranial Pressure in Adults

Oh, Se Kwang; Cho, Yong Chul; Koo, Do Hyun; Ryu, Seung; Lee, Jin Woong; Kim, Seung Whan; Yoo, In Sool; You, Yeon Ho

Abstract

PURPOSE: To evaluate the utility of ONSD (optic nerve sheath diameter) measured by US (ultrasonography) in detecting the presence of increased intracranial pressure.
METHODS
This prospective study was done from October, 2007, to March, 2008. Patients who were 18 years or younger, had a recent ocular or periocular disease, had an abnormal Q test (Queckenstedtis test), or were uncooperative were excluded. The patients were divided into group A (increased CSF pressure group > or =200 mmCSF) and group B (normal CSF pressure <200 mmCSF). The ONSDs were measured using a 3~12 MHz ultrasonographic probe on the closed eyelids. We analyzed the correlation between the CSF (cerebrospinal fluid) pressure and the ONSD.
RESULTS
There were 21 patients in group A and 70 patients in group B. The mean for binocular ONSDs in group A was 5.1+/-0.6 mm and 4.5+/-0.4 mm in group B (plt;0.01). The CSF pressure correlated with the ONSD (Correlation Coefficient=0.54) (plt;0.01). In the ROC curve (Receiver operating characteristic curve) for ONSD to distinguish group A from B, the AUC was 0.8 (95% confidence interval 0.7~0.9) with a sensitivity of 81.0%, and a specificity of 75.7% when the cut off value was set at 4.7 mm.
CONCLUSION
The ONSD was related to the CSF pressure, with a difference in the ONSD between group A and group B. The ONSD, as measured by US, can be used to detect the presence of high ICP.