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Pressure Difference Between Brain and Eye: a Possible Cause to Normal Tension Glaucoma.

Sponsor
Umeå University (Other)
Overall Status
Completed
CT.gov ID
NCT02776449
Collaborator
Västerbotten County Council, Sweden (Other)
17
Enrollment
1
Location
4
Duration (Months)
4.3
Patients Per Site Per Month

Study Details

Study Description

Brief Summary

The main aim of this study is to determine the trans-laminal cribrosa pressure difference (TLCPD) for normal tension glaucoma (NTG) patients from the brain and the eye in supine, upright and minor head down tilt positions. It is also to investigate the venous drainage system in the same body positions.

Condition or Disease Intervention/Treatment Phase

    Detailed Description

    The trans-lamina cribrosa pressure difference (TLCPD), i.e. the difference between the intraocular pressure (IOP) and the intracranial pressure (ICP) has been suggested as a pathophysiological component in glaucoma. The theory is that high TLCPD, either due to elevated IOP or reduced ICP, can cause glaucomatous damage.

    Normal tension glaucoma (NTG) patients has been found to have a slightly reduced ICP when measured in horizontal position. However, in a previous study in healthy adult volunteers the investigators have measured TLCPD at supine, sitting and 9 degree head down tilt positions and found that the TLCPD was posture dependent, with the largest difference in the upright position. Since humans are upright approximately two thirds of the day, one can expect that TLCPD in a diurnal perspective is primarily influenced by the ICP in the upright position.

    In this study the TLCPD in different positions in patients with NTG will therefore be measured.

    The study will be carried out in three parts.

    1. TLCPD will be investigated by simultaneous measurements of IOP and ICP. For IOP the Applanation resonance tonometer (ART), developed by our research group, will be used. ART is independent of gravitation and possible to use in all body postures. In this study measurements will be performed in supine, sitting and head down tilt positions. ICP is measured continuously during the period of body position changes with a CELDA lumbar pressure measurement apparatus.

    2. Brain and eye MRI investigation will be performed at a 3 Tesla GE scanner with a new generation 32-channels head coil. The images will be used to measure the cross-section area, the blood flow velocity and the flow direction in the jugular veins, as well as the structural properties of the optic nerve and optic nerve head.

    3. Ultrasound imaging, using a high-resolution apparatus, will be performed to study the effects of postural changes on the blood flow velocity and the cross-section area of the right and left internal jugular veins and external jugular veins.

    Study Design

    Study Type:
    Observational
    Actual Enrollment :
    17 participants
    Observational Model:
    Case-Only
    Time Perspective:
    Prospective
    Official Title:
    Pathological Cerebral Venous Drainage System Giving Large Pressure Difference Between Brain and Eye at Upright Posture: a Possible Cause to Normal Tension Glaucoma.
    Study Start Date :
    Feb 1, 2016
    Actual Primary Completion Date :
    Jun 1, 2016
    Actual Study Completion Date :
    Jun 1, 2016

    Arms and Interventions

    Arm Intervention/Treatment
    Normal Tension Glaucoma

    Patients with manifest normal tension glaucoma

    Outcome Measures

    Primary Outcome Measures

    1. Trans-lamina cribrosa pressure difference (TLCPD) [1 day Single time point measurement]

      Difference between intraocular pressure (IOP) and intracranial pressure in different body positions

    Secondary Outcome Measures

    1. Postural changes on blood flow velocity and cross-section area of right and left internal jugular veins (IJV) and external jugular veins (EJV) [1 day Single time point measurement]

    Other Outcome Measures

    1. Retinal perfusion using 3D Phase contrast magnetic resonance imaging (3DPCMRI) [1 day Single time point measurement]

    Eligibility Criteria

    Criteria

    Ages Eligible for Study:
    40 Years and Older
    Sexes Eligible for Study:
    All
    Accepts Healthy Volunteers:
    No
    Inclusion Criteria:

    • Subject has normal tension glaucoma in one or both eyes (glaucomatous optic nerve head and corresponding visual field defects)

    • Intraocular pressures before treatment did not exceed 21 mmHg. Occasional measurement up to 24 is accepted.

    Exclusion Criteria:

    • History of brain disease or brain surgery

    • History of other neurologic or ocular disease causing visual field loss

    • Use of anticoagulants other than acetylsalicylic acid

    • Use of carbonic anhydrase inhibitors

    • Previous lumbar puncture

    • Claustrophobia

    Contacts and Locations

    Locations

    Site City State Country Postal Code
    1 Umeå University Umeå Sweden SE-901 85

    Sponsors and Collaborators

    • Umeå University
    • Västerbotten County Council, Sweden

    Investigators

    • Principal Investigator: Jan Malm, MD, Umeå University

    Study Documents (Full-Text)

    None provided.

    More Information

    Publications

    None provided.
    Responsible Party:
    Umeå University
    ClinicalTrials.gov Identifier:
    NCT02776449
    Other Study ID Numbers:
    • NTG-ICP_1
    First Posted:
    May 18, 2016
    Last Update Posted:
    May 3, 2017
    Last Verified:
    May 1, 2016
    Individual Participant Data (IPD) Sharing Statement:
    Undecided
    Plan to Share IPD:
    Undecided
    Additional relevant MeSH terms:
    Glaucoma
    Low Tension Glaucoma

    Study Results

    No Results Posted as of May 3, 2017