Comparison of Pupilometer and Ultrasound of Optic Nerve Sheath Diameter in Estimating Intracranial Pressure (ICP) "CUSPICP"


Phase N/A Results N/A

Trial Description

The purpose of this investigator-initiated study is to compare the use of pupilometer and ultrasound assessment of optic nerve sheath diameter in predicting the ICP and to see if there is a value that could be used to indicate elevated ICP with either modality as these numbers are inconsistent throughout the literature. Patients that have either an external ventricular drain (EVD) or bolt placed will be enrolled in the study. After the EVD and bolt are placed the patient will undergo pupilometer examination (standard of care) followed by ultrasound assessment of the optic nerve sheath diameter (ONSD). The three values will be recorded. The same patient may have multiple readings performed if there is a change in ICP either spontaneously or due to intervention.



  • Ultrasound Device
    Intervention Desc: Type of imaging technology to look at organs and structures inside the body
  • Pupilometer Device
    Intervention Desc: A device that measures pupil size and how it changes.

Trial Population

Adults that have intracranial pathology requiring either EVD or bolt placement for measuring ICP.


Type Measure Time Frame Safety Issue
Primary Measurement of Optic Nerve Sheath Diameter (ONSD) and corresponding intracranial pressure (ICP). 1 day of ONSD examination
Secondary Measurement of Pupillometer reading and corresponding intracranial pressure (ICP). 1 day per nursing protocol (standard of care)