ICP & Outflow Study

NCT06436820 | Not Yet Recruiting

• 1 other identifier: 310393.
• Study Type: observational
• Target: 66
• Locations: 0 countries
• Sites: N/A

Brief Summary

This study aims to investigate the relationship between intracranial pressure (ICP) and aqueous outflow (the flow of the eye's internal fluid out of the eye), in patients with increased intracranial pressure (idiopathic intracranial hypertension (IIH)). Through observing changes in aqueous outflow facility in patients scheduled for lumbar Puncture (LP) as part of their routine care the objectives we aim to answer include:

• Investigating the effect of lumbar puncture induced reduction in ICP on patients with known or suspected IIH, compared to control patients, who will be receiving LP for reasons not pertaining to high pressure.
• Comparing pre lumbar puncture aqueous outflow facility between patients with idiopathic intracranial hypertension and control patients. Outside of the standard care provided for these patients as part of their scheduled lumbar puncture, they will have measurements of their eye taken before and after their lumbar puncture.

Conditions

Eye Change; Idiopathic Intracranial Hypertension

Outcome Measures

Primary Outcomes (1)

• Measure the effect of LP induced change in intracranial pressure on outflow facility in patients with idiopathic intracranial hypertension compared to control patients

  To investigate the effect of lumbar puncture induced changes in intracranial pressure on aqueous outflow facility in patients with known or suspected idiopathic intracranial hypertension, compared to control patients.

  18 Months

Secondary Outcomes (1)

• Measure the difference in outflow facility between patients with idiopathic intracranial hypertension and control patients prior to lumbar puncture

  18 Months

Study Arms (2)

Suspected IIH patient group

Patients with suspected Idiopathic intracranial hypertension, who require a lumbar puncture as part of their standard care.

Procedure: Lumbar puncture

Control group

Patients who require lumbar puncture for reasons not pertaining to raised intracranial pressure as part of their standard care.

Procedure: Lumbar puncture

Interventions

Lumbar puncture PROCEDURE

Lumbar puncture procedure performed within a clinical setting

Control group; Suspected IIH patient group

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients will be recruited from neuro-ophthalmology clinics and neurology clinics in St Thomas hospital London UK

You may qualify if:

• Males or female between the ages of 18 and 80 (inclusive).
• Able to understand the study and give informed consent.
• Willing, able and available to participate in all aspects of the study.
• Able to undergo accurate tonography.
• Diagnosis of Idiopathic intracranial hypertension (IIH) or suspected diagnosis of IIH as determined by a consultant subspecialist neurologist or neuro-ophthalmologist.
• Control group will only include:
• Individuals requiring lumbar puncture as part of their standard care for reasons other than suspected raised intracranial pressure e.g. for cerebrospinal fluid (CSF) sampling to analyse oligoclonal bands or other conditions necessitating lumbar puncture for diagnostic/prognostic purposes.
• Individuals suspected of having a raised intracranial pressure but, upon measurement of the opening pressure, are found to have an intracranial pressure within normal limits.\*
• In this study, where there are considered to be signs of raised intracranial pressure as judged by a consultant neuro ophthalmologist or neurologist, in combination with an opening CSF pressure 20cmH2O or greater, this will be taken as a raised intracranial pressure. Normal CSF pressure is taken as 19cmH2O or lower. In asymptomatic patients, pressures of up to 25cmH2O will be considered normal.

You may not qualify if:

• Under 18 or over 80 years of age.
• Diagnosis of ocular hypertension (ocular hypertension is defined as any individual with an intraocular pressure above 24mmHg measured on Goldman tonometry, irrespective of corneal thickness. This applies to intraocular pressure measured historically as well on the day of assessment).
• Diagnosis of glaucoma of any subtype (glaucoma is defined on the basis of any glaucomatous optic nerve head appearance \[including that defined on the basis of optic nerve head optical coherence tomography\] or visual field defect, irrespective of intraocular pressure).
• Diagnosis of any significant retinal, corneal or other ocular abnormality aside from optic nerve head oedema secondary to raised ICP.
• Previous intraocular surgery or any surgery in which the conjunctiva has been breached e.g. optic nerve sheath fenestration or squint surgery.
• Diagnosis of raised intracranial pressure secondary to space occupying lesions.
• Any central nervous system or other systematic disorder that is likely to make lumbar puncture high risk or likely to render accurate recording of opening pressures unreliable.
• Mental impairment conflicting with informed consent.
• Patients who might not adequately understand written information given in English or verbal explanations in English will not be included as participants in the study must be able to understand English to complete some of the tests.
• Participants will not be included if they are involved in research deemed by the investigators to impact the outcomes of this study.

Sponsors & Collaborators

• Guy's and St Thomas' NHS Foundation Trust: lead

MeSH Terms

Conditions

Pseudotumor Cerebri

Interventions

Spinal Puncture

Condition Hierarchy (Ancestors)

Intracranial Hypertension; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases

Intervention Hierarchy (Ancestors)

Biopsy; Specimen Handling; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Diagnostic Techniques, Neurological; Punctures; Therapeutics; Surgical Procedures, Operative; Investigative Techniques

Central Study Contacts

Kin Sheng Lim

CONTACT

02071884885; sheng.lim@gstt.nhs.uk

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 24, 2024
• First Posted: May 31, 2024
• Study Start: June 1, 2024
• Primary Completion: November 1, 2025
• Study Completion: November 1, 2025
• Last Updated: June 12, 2024

Record last verified: 2024-05

Data Sharing

• IPD Sharing: Will not share