Context: Posttraumatic intracranial hypertension might be detrimental. Bedside ultrasound measurement of optic nerve sheath diameter helps in early diagnosis of increased intracranial pressure.

Aims: To determine the accuracy of detecting the raised intracranial pressure by ultrasonographic measurement of Optic Nerve Sheath Diameter (ONSD). To correlate ONSD with the Computer Tomography (CT) findings of increased intracranial pressure and the average time taken to measure ONSD with ultrasound.

Settings and Design: A Prospective, double blinded Observational Study.

Methods and Materials: To determine the accuracy of detecting the raised intracranial pressure by ultrasonographic measurement of Optic Nerve Sheath Diameter (ONSD). To correlate ONSD with the Computer Tomography (CT) findings of increased intracranial pressure and the average time taken to measure ONSD with ultrasound. Statistical Analysis: Descriptive Analysis - Sensitivity, Specificity and Predictive values.

Results: The sensitivity for the mean binocular optic nerve sheath diameter ultrasonography in detecting elevated intracranial pressure was 99.42% and the specificity was 82.43% with an odds ratio of 0.3547. The positive predictive value was 92.97% and the negative predictive value was 98.39% with an p - value of < 0.0001 which was significant. The average time taken to measure the ONSD was 19.8 secs.

Conclusions: The evaluation of optic nerve sheath diameter is a simple noninvasive procedure, which is a potentially useful tool in the assessment and monitoring of raised intracranial pressure.