<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/NCT01692821</url>
  </required_header>
  <id_info>
    <org_study_id>OPHT-180312</org_study_id>
    <nct_id>NCT01692821</nct_id>
  </id_info>
  <brief_title>Effect of Systemic Hypoxia and Hyperoxia on Retinal Oxygen Saturation</brief_title>
  <official_title>Effect of Systemic Hypoxia and Hyperoxia on Retinal Oxygen Saturation</official_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>
      Adequate perfusion and oxygenation is essential for the function of the inner retina.&#xD;
      Although it is known that oxygen tension is very well autoregulated in the retina, the&#xD;
      physiological mechanisms behind this regulation process are not fully explored. The&#xD;
      development of new instruments for the non-invasive measurement of oxygen tension in retinal&#xD;
      vessels now allows for the more precise investigation of these physiological processes. The&#xD;
      current study seeks to evaluate the retinal oxygen saturation in healthy subjects while&#xD;
      breathing different oxygen mixtures to achieve a hypoxic and a hyperoxic state.&#xD;
    </textblock>
  </brief_summary>
  <overall_status>Completed</overall_status>
  <start_date>June 2012</start_date>
  <completion_date type="Actual">January 2013</completion_date>
  <primary_completion_date type="Actual">December 2012</primary_completion_date>
  <phase>Phase 4</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>Randomized</allocation>
    <intervention_model>Crossover Assignment</intervention_model>
    <primary_purpose>Basic Science</primary_purpose>
    <masking>Triple (Participant, Investigator, Outcomes Assessor)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>Retinal oxygen saturation</measure>
    <time_frame>On the study day - during each breathing period (6 times)</time_frame>
  </primary_outcome>
  <secondary_outcome>
    <measure>Retinal blood flow</measure>
    <time_frame>On the study day - during each breathing period (6 times)</time_frame>
  </secondary_outcome>
  <number_of_arms>3</number_of_arms>
  <enrollment type="Actual">30</enrollment>
  <condition>Retinal Oxygenation</condition>
  <condition>Retinal Blood Flow</condition>
  <arm_group>
    <arm_group_label>100% oxygen breathing</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
  </arm_group>
  <arm_group>
    <arm_group_label>15% oxygen in N2 breathing</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
  </arm_group>
  <arm_group>
    <arm_group_label>12% oxygen in N2 breathing</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
  </arm_group>
  <intervention>
    <intervention_type>Drug</intervention_type>
    <intervention_name>100% oxygen breathing</intervention_name>
    <description>100% oxygen breathing - 30 minutes</description>
    <arm_group_label>100% oxygen breathing</arm_group_label>
  </intervention>
  <intervention>
    <intervention_type>Drug</intervention_type>
    <intervention_name>15% oxygen in N2 breathing</intervention_name>
    <description>15% oxygen in N2 breathing - 30 minutes</description>
    <arm_group_label>15% oxygen in N2 breathing</arm_group_label>
  </intervention>
  <intervention>
    <intervention_type>Drug</intervention_type>
    <intervention_name>12% oxygen in N2 breathing</intervention_name>
    <description>12% oxygen in N2 breathing - 30 minutes</description>
    <arm_group_label>12% oxygen in N2 breathing</arm_group_label>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Men and women aged between 18 and 35 years&#xD;
&#xD;
          -  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 laboratory values unless the investigator considers an abnormality to be&#xD;
             clinically irrelevant&#xD;
&#xD;
          -  Normal ophthalmic findings, ametropy &lt; 3 Dpt.&#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 (except oral contraceptive)&#xD;
&#xD;
          -  Symptoms of a clinically relevant illness in the 3 weeks before the first study day&#xD;
&#xD;
          -  Presence of any form of anemia&#xD;
&#xD;
          -  Blood donation during the previous 3 weeks&#xD;
&#xD;
          -  Pregnancy&#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, Assoc. Prof. Priv.-Doz. Dr.</last_name>
    <role>Principal Investigator</role>
    <affiliation>Department of Clinical Pharmacology, Medical University of Vienna</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Medical University of Vienna, 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>January 2013</verification_date>
  <study_first_submitted>June 14, 2012</study_first_submitted>
  <study_first_submitted_qc>September 20, 2012</study_first_submitted_qc>
  <study_first_posted type="Estimate">September 25, 2012</study_first_posted>
  <last_update_submitted>January 29, 2013</last_update_submitted>
  <last_update_submitted_qc>January 29, 2013</last_update_submitted_qc>
  <last_update_posted type="Estimate">January 30, 2013</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>Assoc. Prof. Priv.-Doz. Dr.</investigator_title>
  </responsible_party>
  <keyword>retinal oxygen saturation</keyword>
  <keyword>retinal blood flow</keyword>
  <keyword>hyperoxia</keyword>
  <keyword>hypoxia</keyword>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Hypoxia</mesh_term>
    <mesh_term>Hyperoxia</mesh_term>
  </condition_browse>
  <!-- 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/NCT01692821
org study id: OPHT-180312
nct id: NCT01692821
lead sponsor: 
has dmc: Yes
Adequate perfusion and oxygenation is essential for the function of the inner retina.
      Although it is known that oxygen tension is very well autoregulated in the retina, the
      physiological mechanisms behind this regulation process are not fully explored. The
      development of new instruments for the non-invasive measurement of oxygen tension in retinal
      vessels now allows for the more precise investigation of these physiological processes. The
      current study seeks to evaluate the retinal oxygen saturation in healthy subjects while
      breathing different oxygen mixtures to achieve a hypoxic and a hyperoxic state.
allocation: Randomized
intervention model: Crossover Assignment
primary purpose: Basic Science
masking: Triple (Participant, Investigator, Outcomes Assessor)
measure: Retinal oxygen saturation
time frame: On the study day - during each breathing period (6 times)
measure: Retinal blood flow
time frame: On the study day - during each breathing period (6 times)
arm group label: 100% oxygen breathing
arm group type: Experimental
arm group label: 15% oxygen in N2 breathing
arm group type: Experimental
arm group label: 12% oxygen in N2 breathing
arm group type: Experimental
intervention type: Drug
intervention name: 100% oxygen breathing
description: 100% oxygen breathing - 30 minutes
arm group label: 100% oxygen breathing
intervention type: Drug
intervention name: 15% oxygen in N2 breathing
description: 15% oxygen in N2 breathing - 30 minutes
arm group label: 15% oxygen in N2 breathing
intervention type: Drug
intervention name: 12% oxygen in N2 breathing
description: 12% oxygen in N2 breathing - 30 minutes
arm group label: 12% oxygen in N2 breathing
criteria: 
gender: All
minimum age: 18 Years
maximum age: 35 Years
healthy volunteers: Accepts Healthy Volunteers
last name: Gerhard Garhöfer, Assoc. Prof. Priv.-Doz. Dr.
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: Assoc. Prof. Priv.-Doz. Dr.
mesh term: Hypoxia
mesh term: Hyperoxia