ONS-SC: Optic nerve sheath diameter sonography in children
Research type
Research Study
Full title
Assessment of the variability in optic nerve sheath diameter and the optic nerve sheath diameter : globe transverse diameter ratio, measured using ultrasound techniques in the paediatric critical care setting.
IRAS ID
312323
Contact name
Joshua Moorhouse
Contact email
Sponsor organisation
Oxford University Hospitals NHS Foundation Trust
Duration of Study in the UK
1 years, 0 months, 0 days
Research summary
Raised pressure within the skull (intracranial pressure (ICP)) can cause brain damage and requires urgent treatment. Behavioural or consciousness changes in children that could be clues of rising ICP are difficult to see in intensive care patients asleep on breathing machines and so they often undergo multiple x-ray head scans or have invasive pressures monitors drilled into their skull. At the back of each eye there is the optic nerve which carries signals from the eye to the brain and is surrounded by a sheath (optic nerve sheath). When the ICP is elevated it can cause this sheath to enlarge, if this could be seen it could spare other invasive assessments of ICP. Traditional examination of this sheath using an ophthalmoscope is technically difficult and so we propose investigating optic sheath measurements using an ultrasound scan which is easier to use and more accurate.
One of the first steps in establishing whether a nerve is enlarged is to understand what is normal. This is not currently known in children when measured using ultrasound machines available in intensive care. It’s also not known how the size of the sheath varies as children grow, and if these variations could be accounted for by also measuring the eyeball and comparing the two as a ratio.
In our study we plan to scan the eyes of children either on intensive care or undergoing general anaesthesia with no known suspicion for raised ICP. The aim is to measure both the optic nerve sheath diameter and the ratio of optic nerve sheath diameter to eyeball diameter, and establish which measurement is more useful. The scan doesn’t hurt or cause any damage, and can be done at the patient's bedside in a few minutes without causing distress as the patients will be asleep on breathing machines.
REC name
Yorkshire & The Humber - Leeds West Research Ethics Committee
REC reference
22/YH/0199
Date of REC Opinion
10 Jan 2023
REC opinion
Further Information Favourable Opinion