Non-Invasive Intracranial Pressure Measurement for Intracranial Hypertension

(ICP Waveform Trial)

Overseen By Igor Nestrasil, MD, PhD

Age: Any Age

Sex: Any

Trial Phase: Academic

Sponsor: University of Minnesota

Disqualifiers: Glaucoma, Retinopathy, Head tremor

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 4

90 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new method to check for high pressure inside the skull without invasive procedures. The study uses a video ophthalmoscope, a special camera, to gather information about intracranial pressure. Researchers divide participants into groups to assess the camera's effectiveness for patients with inserted pressure probes and healthy individuals. Suitable candidates can sit still and focus their eyes during the test; those with intracranial pressure issues should already have a medical pressure probe in place. As an unphased trial, this study allows participants to contribute to innovative research that could lead to non-invasive solutions for monitoring intracranial pressure.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

What prior data suggests that the Video Ophthalmoscope is safe for measuring intracranial pressure?

Research shows that video ophthalmoscopes, the focus of this trial, offer a promising way to measure skull pressure safely without surgery. These devices pose fewer risks than traditional surgical methods, which can lead to infections or bleeding.

Studies have found that video ophthalmoscopes effectively detect changes in skull pressure by examining the eye's optic nerve. This method is generally well-tolerated, with most people experiencing no discomfort or significant side effects. For instance, one study found that a smartphone-based video ophthalmoscope detected certain pressure changes with over 76% accuracy, correctly identifying these changes in many cases.

Overall, past research reports no major negative effects from using video ophthalmoscopes, making them a potentially safer and more comfortable option for measuring skull pressure. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it explores a non-invasive way to measure intracranial pressure (ICP), which could be a game-changer for managing intracranial hypertension. Unlike current methods, which can be invasive and risky, the video ophthalmoscope offers a safer alternative by using eye examinations to estimate ICP. This approach could make monitoring more accessible and less discomforting for patients. The trial aims to refine this technique, potentially leading to a breakthrough in how ICP is assessed, ultimately improving patient care and outcomes.

What evidence suggests that the Video Ophthalmoscope is effective for measuring intracranial pressure?

Studies have shown that video ophthalmoscopes can effectively measure changes in intracranial pressure, which is the pressure inside the skull. One study found that a smartphone-based video ophthalmoscope detected a specific eye feature related to pressure with a sensitivity of about 77-83%, meaning it correctly identified the feature in many cases. This tool is non-invasive, requiring neither surgery nor direct contact with the eye. In this trial, participants will join different experimental groups to evaluate the video ophthalmoscope's effectiveness in measuring intracranial pressure. These findings suggest that video ophthalmoscopes could offer a promising way to monitor intracranial pressure without more invasive methods. ^{1 3 4 6 7}

Who Is on the Research Team?

Igor Nestrasil, MD, PhD

Principal Investigator

University of Minnesota

Are You a Good Fit for This Trial?

This trial is for individuals who can remain still and focus on a target during the video ophthalmoscope (VO) procedure. It's specifically for those with intracranial hypertension who already have an ICP probe inserted for clinical reasons. People with retinopathy, head tremor, or glaucoma cannot participate.

Inclusion Criteria

You need to have a special probe inserted for medical reasons.

I can sit still and focus on a specific point when needed.

Exclusion Criteria

I have been diagnosed with retinopathy.

I have been diagnosed with head tremor.

I have been diagnosed with glaucoma.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Healthy Controls Testing

20 healthy controls test the VO device to determine the most appropriate camera lens and synchronize signals

1 day

1 visit (in-person)

Transfer Function Estimation

Subjects undergo two inter-leaved examinations for SVP-ICP transfer function estimation and intra-group verification

1-14 days

2 visits (in-person)

Intra-Group Verification

Group B participants undergo one examination for inter-group re-test verification of the estimated transfer function

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after testing

2 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Video Ophthalmoscope

Trial Overview The study is testing a non-invasive technique using a video ophthalmoscope to measure intracranial pressure waveforms without touching the eye or needing anesthesia.

How Is the Trial Designed?

Group I: Transfer Function Estimation Experimental Treatment 1 Intervention

Subjects in the second phase of the experiment (70 subjects total) will be randomized to either Group A or Group B. We anticipate that 25 adult and 10 pediatric (ages 4-17) patients will participate in each group. Individuals in Group A will have two inter-leaved examinations (1-14 days apart). Data from the first examination will serve for SVP-ICP transfer function estimation and data from the second examination will serve for the intra-group verification for the estimated transfer function.

Group II: Intra-Group Verification Experimental Treatment 1 Intervention

Individuals in Group B will undergo one examination. Data from Group B participants will serve as the inter-group re-test verification of the estimated transfer function.

Group III: Healthy Controls Experimental Treatment 1 Intervention

In the first phase of the experiment, 20 healthy controls will test the VO device to determine whether the camera with a CCD or CMOS lens is the most appropriate for use in ICP patients and to synchronize the VO, ECG, PPG, IOP and respiratory signals.

Who Is Running the Clinical Trial?

University of Minnesota

Lead Sponsor

Trials

1,459

Recruited

1,623,000+

Hennepin County Medical Center, Minneapolis

Collaborator

Trials

22

Recruited

12,300+

Minnesota Office of Higher Education

Collaborator

Trials

6

Recruited

280+

Published Research Related to This Trial

A new noninvasive method for measuring absolute intracranial pressure (ICP) using two-depth transcranial Doppler technology has been validated through multicenter clinical studies, making it a promising tool for clinical use.

This method uniquely utilizes the ophthalmic artery as a natural pressure sensor, allowing for accurate ICP measurement without the need for patient-specific calibration, enhancing its practicality in medical settings.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Accuracy, Precision, Sensitivity, and Specificity of Noninvasive ICP Absolute Value Measurements. Krakauskaite, S., Petkus, V., Bartusis, L., et al.[2017]

Vivonics, Inc. is developing a noninvasive device called IPASS that uses near-infrared sensors to assess intracranial pressure (ICP), which is crucial for managing symptoms of intracranial hypertension (IH) without the need for invasive procedures.

The IPASS system measures hemodynamic oscillations and correlates them with ICP changes, potentially providing a practical solution for emergency medical personnel to monitor ICP and improve patient outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A Noninvasive Method for Monitoring Intracranial Pressure During Postural Changes. Pierro, ML., Shooshan, NM., Deshmukh, S., et al.[2021]

Optical coherence tomography is emerging as a valuable tool for assessing disease activity in idiopathic intracranial hypertension, potentially serving as a measure for both papilledema and intracranial pressure.

Standardizing treatment outcomes for headache management is crucial, as chronic headaches significantly impact patients' quality of life, and this will facilitate better comparisons across clinical trials.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Outcomes measures in idiopathic intracranial hypertension. Mollan, SP., Sinclair, AJ.[2022]

Advancements in technology have made intracranial pressure measurement more accessible, which is crucial for managing cerebrospinal fluid disorders that affect vision, headache, cognition, and overall quality of life.

This review highlights the importance of intracranial pressure monitoring for neuro-ophthalmologists and neurologists, as it can significantly inform their management decisions in clinical practice.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A Neuro-Ophthalmologist's Guide to Advances in Intracranial Pressure Measurements. Mollan, SP., Momin, SNA., Khatkar, PS., et al.[2023]

Non-invasive monitoring of intracranial pressure (ICP) can be achieved by observing pulsations in retinal blood vessels when intraocular pressure (IOP) exceeds ICP, with an accuracy of 77% in detecting these pulsations.

This method offers a safer alternative to invasive procedures like lumbar punctures, potentially improving patient outcomes by minimizing trauma and complications associated with traditional ICP assessment techniques.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Non-Invasive Measurement of Intracranial Pressure Through Application of Venous Ophthalmodynamometry. Lo, L., Zhao, D., Ayton, L., et al.[2022]

The systematic review and meta-analysis of 12 studies involving 546 patients found a moderate correlation (0.44) between intraocular pressure (IOP) and intracranial pressure (ICP), suggesting that IOP could be a useful noninvasive indicator of intracranial hypertension.

IOP measurement demonstrated a sensitivity of 81% and specificity of 95% for diagnosing intracranial hypertension, indicating it may be a reliable diagnostic tool, although further research is needed due to significant variability among studies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Diagnostic accuracy of intraocular pressure measurement for the detection of raised intracranial pressure: meta-analysis: a systematic review. Yavin, D., Luu, J., James, MT., et al.[2019]

In a pilot study involving 27 patients with invasive intracranial pressure monitors, abnormal intraocular pressure was found to perfectly correlate with abnormal intracranial pressure, demonstrating a sensitivity and specificity of 100%.

The handheld tonometer can serve as a reliable noninvasive tool for early detection of intracranial hypertension, potentially allowing for timely medical and surgical interventions to prevent severe complications.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The relationship of intraocular pressure to intracranial pressure. Lashutka, MK., Chandra, A., Murray, HN., et al.[2019]

In a study of 25 patients suspected of having idiopathic intracranial hypertension, retinal vessel dynamics analysis showed a significant difference in the arteriole-to-venule ratio between those with and without the condition, indicating its potential as a non-invasive marker for increased intracranial pressure.

The arteriole-to-venule ratio correlated inversely with lumbar opening pressure, demonstrating high sensitivity (78%) and specificity (92%) for predicting elevated cerebrospinal fluid pressure, particularly when lumbar pressure exceeded 20 mm Hg.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Retinal vessel dynamics analysis as a surrogate marker for raised intracranial pressure in patients with suspected idiopathic intracranial hypertension. Hagen, SM., Wibroe, EA., Korsbæk, JJ., et al.[2023]

Idiopathic intracranial hypertension (IIH) is characterized by increased intracranial pressure, leading to symptoms like headaches, visual disturbances, and potential sixth nerve palsy, with diagnosis confirmed through brain imaging and lumbar puncture.

Treatment strategies focus on weight loss and, in cases of rapid visual decline, urgent surgical intervention is necessary to prevent permanent vision loss, highlighting the chronic and disabling nature of the condition.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Idiopathic intracranial hypertension: Update on diagnosis and management. Wakerley, BR., Mollan, SP., Sinclair, AJ.[2021]

A study of 105 patients found that the absence of spontaneous retinal venous pulsation, assessed through infrared video, is significantly linked to higher intracranial pressure, suggesting it could be a reliable noninvasive indicator of intracranial hypertension.

The results indicate that this method could reduce the need for invasive procedures like lumbar punctures, as it allows for timely identification and treatment of patients with raised intracranial pressure.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Association of Intracranial Pressure and Spontaneous Retinal Venous Pulsation. D'Antona, L., McHugh, JA., Ricciardi, F., et al.[2021]

Non-invasive methods for measuring intracranial pressure (ICP) are essential alternatives to invasive techniques, which, while accurate, carry risks and limitations. This review discusses eight non-invasive methods, including optic nerve sheath diameter and pupillometry, highlighting their potential in specific clinical scenarios.

While non-invasive ICP measurement methods cannot fully replace invasive techniques, they offer significant advantages in safety and applicability, making them valuable tools for monitoring ICP in certain patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A Review of the Methods of Non-Invasive Assessment of Intracranial Pressure through Ocular Measurement. Dong, J., Li, Q., Wang, X., et al.[2022]

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT04046523?cond=Hypertension

Non-Invasive and Non-Contact Intracranial Pressure ... This study will test the use of a video ophthalmoscope that will calculate the relative waveform of intracranial pressure and provide information about ...

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11545690/

Non-invasive assessment of intracranial pressure through the ... Another study investigated the validity of smartphone-based video ophthalmoscopy for detecting SVP in 233 patients, finding a sensitivity of 82.77 and 76.82 ...

3. neurology.org neurology.org/doi/10.1212/WNL.0000000000004868

Ophthalmoscopy in the 21st century The Fundus Photography vs Ophthalmoscopy Trial Outcomes in the Emergency Department (FOTO-ED) study showed that ED providers consistently failed to correctly ...

4. aging.networkofcare.org aging.networkofcare.org/sanmateo/CommunityResources/ClinicalTrials/Detail/NCT04046523?keyword=%22Electrocardiogram%22

Non-Invasive and Non-Contact Intracranial Pressure ... This study will test the use of a video ophthalmoscope that will calculate the relative waveform of intracranial pressure and provide information about ...

5. researchgate.net researchgate.net/figure/Results-of-Two-Observers-for-the-Identification-of-SVP-on-Video-Being-Present-on-Slit_tbl3_338999490

Results of Two Observers for the Identification of SVP on Video ... The objective was to determine if smartphone-based video ophthalmoscopy can detect SVP. Patients and Methods In total 233 patients and 291 eyes were recruited ...

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC8107303/

Non-invasive detection of intracranial pressure related to the ... This review summarizes the non-invasive ICP detection methods related to the optic nerve and the role of the diagnosis and prognosis of neurological disorders ...

7. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0967586824005411

A prospective observational study on intracranial pressure ... However, EVD carries risks of complications, including infection, hemorrhage, cerebrospinal fluid leakage, obstruction, and catheter displacement [7], [8]. The ...