<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT01663883</url>
  </required_header>
  <id_info>
    <org_study_id>OPHT-210911</org_study_id>
    <nct_id>NCT01663883</nct_id>
  </id_info>
  <brief_title>Optic Nerve Head Autoregulation During Changes in Arterial Blood Pressure</brief_title>
  <sponsors>
    <lead_sponsor>
      <agency>Medical University of Vienna</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Medical University of Vienna</source>
  <oversight_info>
    <has_dmc>Yes</has_dmc>
  </oversight_info>
  <brief_summary>
    <textblock>
      Constant despite changes in perfusion pressure. It is observed in many vascular beds of the&#xD;
      human body to prevent that variations in perfusion pressure are directly transmitted into&#xD;
      changes in blood flow. This is necessary to prevent ischemia and/or hypoxia during decreased&#xD;
      blood flow and bleeding or increased capillary pressure during increased blood flow.&#xD;
&#xD;
      In the eye, several studies have reported that retinal blood flow is autoregulated over a&#xD;
      wide range of ocular perfusion pressures. Unfortunately only few data are available for the&#xD;
      optic nerve head. To gain data about autoregulation is of special importance given that&#xD;
      several important ocular diseases such as glaucoma and age-related macular degeneration are&#xD;
      associated with impaired autoregulation. In humans most data were collected using laser&#xD;
      Doppler flowmetry.&#xD;
&#xD;
      The present study aims to investigate the phenomenon of transient reduction in blood flow and&#xD;
      to gain insight in the regulatory mechanisms of optic nerve head blood flow during isometric&#xD;
      exercise.&#xD;
    </textblock>
  </brief_summary>
  <overall_status>Completed</overall_status>
  <start_date>February 2012</start_date>
  <completion_date type="Actual">August 2012</completion_date>
  <primary_completion_date type="Actual">April 2012</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>N/A</allocation>
    <intervention_model>Single Group Assignment</intervention_model>
    <primary_purpose>Basic Science</primary_purpose>
    <masking>None (Open Label)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>Optic nerve head blood flow</measure>
    <time_frame>12 minutes</time_frame>
  </primary_outcome>
  <secondary_outcome>
    <measure>Systolic/diastolic blood pressure</measure>
    <time_frame>14 minutes</time_frame>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Intraocular pressure</measure>
    <time_frame>at baseline and minute 13</time_frame>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Pulse rate</measure>
    <time_frame>14 minutes</time_frame>
  </secondary_outcome>
  <number_of_arms>1</number_of_arms>
  <enrollment type="Actual">40</enrollment>
  <condition>Decreased Vascular Flow</condition>
  <arm_group>
    <arm_group_label>Healthy subjects</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
  </arm_group>
  <intervention>
    <intervention_type>Other</intervention_type>
    <intervention_name>Isometric exercise</intervention_name>
    <description>use of a handgrip for 3x2 minutes</description>
    <arm_group_label>Healthy subjects</arm_group_label>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Men and women aged between 18 and 35 years, nonsmokers&#xD;
&#xD;
          -  Normal findings in the medical history and physical examination unless the&#xD;
             investigator considers an abnormality to be clinically irrelevant&#xD;
&#xD;
          -  Normal ophthalmic findings, ametropia less than 3 diopters&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Regular use of medication, abuse of alcoholic beverages, participation in a clinical&#xD;
             trial in the 3 weeks preceding the study&#xD;
&#xD;
          -  Treatment in the previous 3 weeks with any drug (except oral contraceptives)&#xD;
&#xD;
          -  Symptoms of a clinically relevant illness in the 3 weeks before the first study day&#xD;
&#xD;
          -  Blood donation during the previous 3 weeks&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>35 Years</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Gerhard Garhöfer, MD</last_name>
    <role>Principal Investigator</role>
    <affiliation>Department of Clinical Pharmacology, Medical University of Vienna</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Department of Clinical Pharmacology</name>
      <address>
        <city>Vienna</city>
        <zip>1090</zip>
        <country>Austria</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>Austria</country>
  </location_countries>
  <verification_date>August 2012</verification_date>
  <study_first_submitted>January 24, 2012</study_first_submitted>
  <study_first_submitted_qc>August 9, 2012</study_first_submitted_qc>
  <study_first_posted type="Estimate">August 13, 2012</study_first_posted>
  <last_update_submitted>August 9, 2012</last_update_submitted>
  <last_update_submitted_qc>August 9, 2012</last_update_submitted_qc>
  <last_update_posted type="Estimate">August 13, 2012</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Medical University of Vienna</investigator_affiliation>
    <investigator_full_name>Gerhard Garhofer</investigator_full_name>
    <investigator_title>Ass. Prof. Priv. Doz. Dr.</investigator_title>
  </responsible_party>
  <keyword>Blood flow autoregulation</keyword>
  <keyword>optic nerve head blood flow</keyword>
  <keyword>isometric exercise</keyword>
  <keyword>Autoregulation</keyword>
  <keyword>ocular physiology</keyword>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT01663883
org study id: OPHT-210911
nct id: NCT01663883
lead sponsor: 
has dmc: Yes
Constant despite changes in perfusion pressure. It is observed in many vascular beds of the
      human body to prevent that variations in perfusion pressure are directly transmitted into
      changes in blood flow. This is necessary to prevent ischemia and/or hypoxia during decreased
      blood flow and bleeding or increased capillary pressure during increased blood flow.

      In the eye, several studies have reported that retinal blood flow is autoregulated over a
      wide range of ocular perfusion pressures. Unfortunately only few data are available for the
      optic nerve head. To gain data about autoregulation is of special importance given that
      several important ocular diseases such as glaucoma and age-related macular degeneration are
      associated with impaired autoregulation. In humans most data were collected using laser
      Doppler flowmetry.

      The present study aims to investigate the phenomenon of transient reduction in blood flow and
      to gain insight in the regulatory mechanisms of optic nerve head blood flow during isometric
      exercise.
allocation: N/A
intervention model: Single Group Assignment
primary purpose: Basic Science
masking: None (Open Label)
measure: Optic nerve head blood flow
time frame: 12 minutes
measure: Systolic/diastolic blood pressure
time frame: 14 minutes
measure: Intraocular pressure
time frame: at baseline and minute 13
measure: Pulse rate
time frame: 14 minutes
arm group label: Healthy subjects
arm group type: Experimental
intervention type: Other
intervention name: Isometric exercise
description: use of a handgrip for 3x2 minutes
arm group label: Healthy subjects
criteria: 
gender: All
minimum age: 18 Years
maximum age: 35 Years
healthy volunteers: Accepts Healthy Volunteers
last name: Gerhard Garhöfer, MD
role: Principal Investigator
affiliation: Department of Clinical Pharmacology, Medical University of Vienna
facility: 
country: Austria
responsible party type: Principal Investigator
investigator affiliation: Medical University of Vienna
investigator full name: Gerhard Garhofer
investigator title: Ass. Prof. Priv. Doz. Dr.