Optic nerve sheath diameter sonography to assess intracranial pressure
Research type
Research Study
Full title
Sonographic measurement of optic nerve sheath diameter to assess intracranial pressure in patients with suspected or confirmed elevated intracranial pressure.
IRAS ID
291168
Contact name
Jon Beishon
Contact email
Sponsor organisation
Lancashire Teaching Hospitals NHS Foundation Trust
Duration of Study in the UK
0 years, 3 months, 1 days
Research summary
Research Summary
Title: Ultrasound of optic nerve sheath diameter to assess intracranial pressure in patients with suspected or confirmed raised intracranial pressure.
Background: Patients who suffer brain injury often have elevated intracranial pressure (ICP). This can cause brain injury that can result in death or permanent disability. Normally a monitor is inserted into the brain of these patients by neurosurgeons to monitor the ICP and maintain it at a safe level. There are risks associated with this surgical procedure including infection and haemorrhage, and there is also have a chance of the devices malfunctioning. An alternative way of assessing intracranial pressure that does not require invasive techniques is using ultrasound to measure the width of the sheath surrounding the optic nerve behind the eye. This technique could assist clinical decision-making by allowing rapid assessment and triage of patients with suspected ICP to facilitate timely and appropriate treatment.
Aim: This study will investigate whether optic nerve diameter correlates with ICP and if this approach is feasible in clinical practice.
Design: This study will take place over a three month time-frame and recruit roughly 30 patients with suspected or confirmed raised ICP. Such patients will initially be unconscious due to the nature of their injury and admitted to the intensive care unit at Royal Preston Hospital, a large tertiary centre for neurosurgery. The urgency of immediate care delivery means retrospective consent from the patient, relative or clinical team will be sought.
Investigations: Ultrasound will be used to measure the width of the optic nerve in both eyes. The ultrasound will be carried out by members of the research team who are also part of the treating medical team and trained medical physicians. The whole investigation will take only a few minutes.
Analysis: The data will be anonymised and analysed by members of the research team.
Summary of Results
A study was undertaken to see if the pressure inside the brain could be estimated by using ultrasound to measure the width of the optic nerve sheath (the main nerve that carries signals from the eye) behind the eye. Patients were recruited from an intensive care unit in a busy tertiary centre. These patients had bolts put in their heads by neurosurgeons to accurately measure the pressure in the brain. We found that the width of the optic nerve does correlate with the pressure inside the brain. However, this only held true for patients who have not had craniectomies - a type of brain surgery that involves removing a piece of skull to relieve pressure. In the patients who had craniectomies, there was no significant correlation. These findings support previous research done in this area, and the finding that readings are not accurate in patients with craniectomies is important as this is a patient group that has not been studied very much before.
REC name
Wales REC 3
REC reference
21/WA/0005
Date of REC Opinion
17 Feb 2021
REC opinion
Further Information Favourable Opinion