Eye ChangeNCT06436820
ICP & Outflow Study
An observational study of Eye Change and Idiopathic Intracranial Hypertension, run by Guy's and St Thomas' NHS Foundation Trust.
Trial 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)). Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Eye Change, Idiopathic Intracranial Hypertension
- What is being tested?
- Lumbar puncture
- Type of treatment
- Surgery or procedure
- How many people
- 66 participants
- Where
- No sites listed yet
- Study dates
- Jun 2024to Nov 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 80 years
- All sexes
- Adult, Older adult
Study population: Patients will be recruited from neuro-ophthalmology clinics and neurology clinics in St Thomas hospital London UK
Who may be able to join
- 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:
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- 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.
Who cannot join
- 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.
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- 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.
Trial locations and contacts
No sites are listed yet.
About this study
Official title: The Relationship Between Intracranial Pressure and Aqueous Outflow in Idiopathic Intracranial Hypertension
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:
Read more
- 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.
Read the detailed description
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)).
The effect of lowering intracranial pressure on aqueous outflow will be examined by taking additional measurements before and after a procedure called a lumbar puncture (LP). These measurements include a scan to measure the dimensions of the eye, intraocular pressure reading, and a non-invasive technique to measure aqueous outflow (electronic Schiotz tonography) which is used regularly in the eye research unit at St Thomas' Hospital.
Study participants will already be scheduled for a lumbar puncture as they have known or suspected IIH, and LP is routinely used to investigate this. Additionally, control participants having LP for reasons not pertaining to a condition that may elevate intracranial pressure will also be included. Study participants will finish their involvement following the second aqueous outflow reading, after their LP.
A lumbar puncture procedure directly measures the intracranial pressure, but also reduces the pressure in the process. If aqueous outflow is measured before and after lumbar puncture, it will provide more information about whether the change in intracranial pressure affects the intraocular pressure due to a change in the rate of fluid flowing out of the eye. If a relationship between intracranial pressure and aqueous outflow is found to be present, it may offer an alternative non-invasive measurement for intracranial pressure. Additionally, this study would highlight an avenue of investigation into dysregulation of intraocular pressure in conditions such as glaucoma. Similarly, negative findings would help inform ongoing discussions and controversies in the literature regarding relationships between intraocular pressure and intracranial pressure.
- Conditions
- Eye Change, Idiopathic Intracranial Hypertension
- Being tested
- Lumbar puncture
- Medical subject headings
- Pseudotumor Cerebri
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Lumbar punctureProcedure or surgery
Lumbar puncture procedure performed within a clinical setting
| Study group | Role | What they receive |
|---|---|---|
| Suspected IIH patient group | Patients with suspected Idiopathic intracranial hypertension, who require a lumbar puncture as part of their standard care. Receives: Procedure: Lumbar puncture | |
| Control group | Patients who require lumbar puncture for reasons not pertaining to raised intracranial pressure as part of their standard care. Receives: Procedure: Lumbar puncture |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 18 Months
Secondary outcomes (1)
Measure the difference in outflow facility between patients with idiopathic intracranial hypertension and control patients prior to lumbar puncture
To compare pre lumbar puncture aqueous outflow facility between patients with idiopathic intracranial hypertension and control patients.
Measured: 18 Months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 May 2024
- Study startJun 2024 (estimated)
- Primary completionNov 2025 (estimated)
- Study completionNov 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Eye ChangeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 66 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Guy's and St Thomas' NHS Foundation Trust
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06436820
- Sponsor's protocol ID
- 310393.
- Status last verified
- May 2024
- First submitted
- 24 May 2024
- Last updated
- 12 Jun 2024
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 12 Jun 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Relationship Between Intracranial Pressure and Aqueous Outflow in Idiopathic Intracranial Hypertension
- ClinicalTrials.gov ID
- NCT06436820
- Acronym / sponsor ID
- 310393.
- Conditions
- Eye Change, Idiopathic Intracranial Hypertension
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 66 participants (estimated)
- Lead sponsor
- Guy's and St Thomas' NHS Foundation TrustUniversity, hospital or other
- Study start
- Jun 2024 (estimated)
- Primary completion
- Nov 2025 (estimated)
- Study completion
- Nov 2025 (estimated)
- First posted
- 31 May 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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)).
The effect of lowering intracranial pressure on aqueous outflow will be examined by taking additional measurements before and after a procedure called a lumbar puncture (LP). These measurements include a scan to measure the dimensions of the eye, intraocular pressure reading, and a non-invasive technique to measure aqueous outflow (electronic Schiotz tonography) which is used regularly in the eye research unit at St Thomas' Hospital.
Study participants will already be scheduled for a lumbar puncture as they have known or suspected IIH, and LP is routinely used to investigate this. Additionally, control participants having LP for reasons not pertaining to a condition that may elevate intracranial pressure will also be included. Study participants will finish their involvement following the second aqueous outflow reading, after their LP.
A lumbar puncture procedure directly measures the intracranial pressure, but also reduces the pressure in the process. If aqueous outflow is measured before and after lumbar puncture, it will provide more information about whether the change in intracranial pressure affects the intraocular pressure due to a change in the rate of fluid flowing out of the eye. If a relationship between intracranial pressure and aqueous outflow is found to be present, it may offer an alternative non-invasive measurement for intracranial pressure. Additionally, this study would highlight an avenue of investigation into dysregulation of intraocular pressure in conditions such as glaucoma. Similarly, negative findings would help inform ongoing discussions and controversies in the literature regarding relationships between intraocular pressure and intracranial pressure.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Suspected IIH patient group | – | Procedure: Lumbar puncturePatients with suspected Idiopathic intracranial hypertension, who require a lumbar puncture as part of their standard care. |
| Control group | – | Procedure: Lumbar puncturePatients who require lumbar puncture for reasons not pertaining to raised intracranial pressure as part of their standard care. |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Age groups
- Adult, Older adult
- Study population
- Patients will be recruited from neuro-ophthalmology clinics and neurology clinics in St Thomas hospital London UK
Key inclusion criteria (9 listed)
- 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.
Key exclusion criteria (10 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Lumbar punctureLumbar puncture procedure performed within a clinical setting | Procedure or surgery | Control group, Suspected IIH patient group |
Primary outcome
Measure the effect of LP induced change in intracranial pressure on outflow facility in patients with idiopathic intracranial hypertension compared to control patients
Time frame: 18 Months
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.
1 secondary outcome
Measure the difference in outflow facility between patients with idiopathic intracranial hypertension and control patients prior to lumbar puncture
Time frame: 18 Months
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Jun 2024.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Questions about this trial
What is this clinical trial studying?
An observational study of Eye Change and Idiopathic Intracranial Hypertension, run by Guy's and St Thomas' NHS Foundation Trust.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 12 Jun 2024. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Kin Sheng Lim (02071884885, sheng.lim@gstt.nhs.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Measure the effect of LP induced change in intracranial pressure on outflow facility in patients with idiopathic intracranial hypertension compared to control patients (time frame: 18 Months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Jun 2024.