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

Trial Summary

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 data supports the effectiveness of the treatment Video Ophthalmoscope, Dynamic Video Ophthalmoscope, Video Ophthalmoscopy Device for measuring intracranial pressure?

Research suggests that measuring intraocular pressure (pressure inside the eye) can help detect increased intracranial pressure (pressure inside the skull) noninvasively, which is important for early intervention in conditions like intracranial hypertension. ^{1 2 3 4 5}

Is the non-invasive intracranial pressure measurement method safe for humans?

The non-invasive method for measuring intracranial pressure, which involves observing retinal blood vessels, is considered safe as it avoids the trauma and complications associated with invasive procedures like lumbar punctures. ^{3 6 7 8 9}

How is the Video Ophthalmoscope treatment different from other treatments for intracranial hypertension?

The Video Ophthalmoscope treatment is unique because it offers a non-invasive way to measure intracranial pressure by observing changes in the eye, specifically using video technology to monitor retinal blood vessels. This approach avoids the need for invasive procedures like inserting sensors into the brain, making it safer and more comfortable for patients. ^{1 2 8 10 11}

What is the purpose of this trial?

This study will test the use of video ophthalmoscope to provide information about intracranial pressure without the use of invasive methods, anesthesia or contact with the eye.

Research Team

Igor Nestrasil, MD, PhD

Principal Investigator

University of Minnesota

Eligibility Criteria

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

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

Treatment Details

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.

Participant Groups

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+

Findings from Research

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

References

1. Austria pubmed.ncbi.nlm.nih.gov

Accuracy, Precision, Sensitivity, and Specificity of Noninvasive ICP Absolute Value Measurements. [2017]

2. United States pubmed.ncbi.nlm.nih.gov

The relationship of intraocular pressure to intracranial pressure. [2019]

3. United States pubmed.ncbi.nlm.nih.gov

Association of Intracranial Pressure and Spontaneous Retinal Venous Pulsation. [2021]

4. United States pubmed.ncbi.nlm.nih.gov

Diagnostic accuracy of intraocular pressure measurement for the detection of raised intracranial pressure: meta-analysis: a systematic review. [2019]

5. New Zealand pubmed.ncbi.nlm.nih.gov

A Neuro-Ophthalmologist's Guide to Advances in Intracranial Pressure Measurements. [2023]

6. England pubmed.ncbi.nlm.nih.gov

Idiopathic intracranial hypertension: Update on diagnosis and management. [2021]

7. England pubmed.ncbi.nlm.nih.gov

Outcomes measures in idiopathic intracranial hypertension. [2022]

8. United States pubmed.ncbi.nlm.nih.gov

Non-Invasive Measurement of Intracranial Pressure Through Application of Venous Ophthalmodynamometry. [2022]

9. England pubmed.ncbi.nlm.nih.gov

Retinal vessel dynamics analysis as a surrogate marker for raised intracranial pressure in patients with suspected idiopathic intracranial hypertension. [2023]

10. Switzerland pubmed.ncbi.nlm.nih.gov

A Review of the Methods of Non-Invasive Assessment of Intracranial Pressure through Ocular Measurement. [2022]

11. Austria pubmed.ncbi.nlm.nih.gov

A Noninvasive Method for Monitoring Intracranial Pressure During Postural Changes. [2021]