PhNR in the diagnosis and monitoring of raised intracranial pressure
Research type
Research Study
Full title
The Photopic Negative Response (PhNR) of the Electroretinogram in the diagnosis and monitoring of raised intracranial pressure in children.
IRAS ID
246601
Contact name
Oliver R Marmoy
Contact email
Sponsor organisation
Manchester Metropoliton University
Duration of Study in the UK
0 years, 7 months, 15 days
Research summary
Patients with raised intracranial pressure (rICP) can suffer symptoms of severe headaches, double vision and compression of the nerve serving the eye known as an Optic Neuropathy. Due to the nature of this condition, the high pressure of the cerebro-spinal fluid surrounding the brain transfers to the sheath surrounding the optic nerve or pushes portions of the visual pathway which causes deterioration of the patients peripheral vision. This poses a significant risk to patients vision if not reversed or treated appropriately.\n\nIt is essential clinically that patients are monitored regularly to avoid irreversible vision loss. Current local protocol involves imaging techniques alongside Visual Evoked Potential (VEP) and standard Electroretinography (ERG) tests to monitor the patients visual function when rICP is known or suspected. The scientific limitation of these methods, however, is that the VEP is a test of the central portion of the eye only which often remains unaffected until late disease stages. Conversely the standard ERG is predominantly a test of the middle and outer retinal layers. New ISCEV standard protocols have introduced the new technique Photopic Negative Response (PhNR) of the ERG, which allows recording of the inner neural layers of the retina, which are affected during rICP. This technique has the potential for increased sensitivity in disease monitoring over VEPs alone, as we are able to quantify the contribution of Retinal Ganglion Cell (RGC), the neural cells of the inner retina, function over the entire central and peripheral field areas. \n\nWe wish to study the PhNR in patients with rICP in two patient groups; those with Idiopathic Intracranial Hypertension and those with Craniosynostosis. Cross-sectional analysis will be performed comparing with imaging (OCT/Optos imaging) to correlate potential optic disc appearance and quantitative loss of the Retinal Ganglion Cell layer (i.e. the neural portion of the retina studied by the PhNR).\n
REC name
London - Brighton & Sussex Research Ethics Committee
REC reference
18/LO/1035
Date of REC Opinion
29 Aug 2018
REC opinion
Further Information Favourable Opinion