<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/NCT04491500</url>
  </required_header>
  <id_info>
    <org_study_id>2020051</org_study_id>
    <nct_id>NCT04491500</nct_id>
  </id_info>
  <brief_title>Retinal and Choroidal Circulation Changes Following Rapid Ascent to a High Altitude Environment</brief_title>
  <official_title>Retinal and Choroidal Circulation Changes Following Rapid Ascent to a High Altitude Environment Evaluated by OCT Angiography</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Zhongshan Ophthalmic Center, Sun Yat-sen University</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Zhongshan Ophthalmic Center, Sun Yat-sen University</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      This is a prospective observational study. The purpose is to explore the effect of high&#xD;
      altitude hypobaric hypoxia on retinal microcirculation and the change of the thickness of the&#xD;
      retina and choroid by optical coherence tomography angiography (OCTA).&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Yushu is in Qinghai-Tibet plateau, an average altitude of 4000 m. The medical staff is&#xD;
      limited in Yushu. Zhongshan ophthalmic center, sun yat-sen university in Yushu blindness&#xD;
      project has lasted many years. Some medical staff who arrived at Yushu will have a plateau&#xD;
      response. The high altitude hypoxia on retinal microcirculation evaluated by OCTA has not&#xD;
      been reported. The aim of the study is to observe the microcirculation changes after&#xD;
      exploring a hypobaric and hypoxia environment using OCTA, and relation with the plateau&#xD;
      response. OCTA is a non-invasive examination and could see the microcirculation of the fundus&#xD;
      directly and quickly.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date type="Actual">July 27, 2020</start_date>
  <completion_date type="Actual">September 10, 2020</completion_date>
  <primary_completion_date type="Actual">August 20, 2020</primary_completion_date>
  <study_type>Observational</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <observational_model>Other</observational_model>
    <time_perspective>Prospective</time_perspective>
  </study_design_info>
  <primary_outcome>
    <measure>retinal microcirculation changes</measure>
    <time_frame>1 month</time_frame>
    <description>the vascular density measured by OCTA</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Retinal thickness changes</measure>
    <time_frame>1 month</time_frame>
    <description>the retinal thickness measured by OCTA</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Choroidal thickness changes</measure>
    <time_frame>1 month</time_frame>
    <description>the subfoveal choroidal thickness measured by OCTA</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>The correlation of retinal microcirculation with the altitude illness</measure>
    <time_frame>1 month</time_frame>
    <description>The relationship between retinal vascular density as measured by OCTA and the degree of altitude illness as measured by acute mountain sickness (AMS) scoring system</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>The changes of intraocular pressure</measure>
    <time_frame>1 month</time_frame>
    <description>The changes of intraocular pressure measured by icare Tonometer</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>The changes of blood pressure including systolic and diastolic Blood Pressure</measure>
    <time_frame>1 month</time_frame>
    <description>The changes of blood pressure measured by Blood Pressure Meter</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>The changes of blood oxygen</measure>
    <time_frame>1 month</time_frame>
    <description>The changes of blood Oxygen measured by Pulse Oximeter</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>the degree of altitude illness</measure>
    <time_frame>1 month</time_frame>
    <description>the degree of altitude illness was assessed by acute mountain sickness (AMS) scoring system</description>
  </secondary_outcome>
  <number_of_groups>1</number_of_groups>
  <enrollment type="Actual">13</enrollment>
  <condition>High Altitude Retinopathy</condition>
  <arm_group>
    <arm_group_label>study group</arm_group_label>
    <description>This is a self-control study. Subjects who plan togo to 4000m altitude to work for two weeks will be enrolled. And before and after they arrive high altitude, they will have visual acuity, OCTA, and intraocular pressure; blood pressure, blood oxygen measurement.</description>
  </arm_group>
  <intervention>
    <intervention_type>Behavioral</intervention_type>
    <intervention_name>High attitude environment</intervention_name>
    <description>The participants will go to 4000m altitude to work for two weeks.</description>
    <arm_group_label>study group</arm_group_label>
  </intervention>
  <eligibility>
    <study_pop>
      <textblock>
        the staff will go to Yushu on the 2020 preventive blindness project.&#xD;
      </textblock>
    </study_pop>
    <sampling_method>Non-Probability Sample</sampling_method>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          1. The subjects who plan to go to Yushu within one month.&#xD;
&#xD;
          2. Did not live on the high altitude of more than 1000 meters within 6 months.&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          1. Unable and unwilling to provide informed consent.&#xD;
&#xD;
          2. Any ocular disease may influence the retinal and choroidal circulation.&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>70 Years</maximum_age>
  </eligibility>
  <overall_official>
    <last_name>Xiaoling Liang, M.D</last_name>
    <role>Principal Investigator</role>
    <affiliation>Zhongshan Ophthalmic Center, Sun Yat-sen University</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Liang xiaoling</name>
      <address>
        <city>Guangzhou</city>
        <state>Guangdong</state>
        <zip>510000</zip>
        <country>China</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>China</country>
  </location_countries>
  <verification_date>September 2020</verification_date>
  <study_first_submitted>July 22, 2020</study_first_submitted>
  <study_first_submitted_qc>July 25, 2020</study_first_submitted_qc>
  <study_first_posted type="Actual">July 29, 2020</study_first_posted>
  <last_update_submitted>September 15, 2020</last_update_submitted>
  <last_update_submitted_qc>September 15, 2020</last_update_submitted_qc>
  <last_update_posted type="Actual">September 16, 2020</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Zhongshan Ophthalmic Center, Sun Yat-sen University</investigator_affiliation>
    <investigator_full_name>Shanshan Yu, MD</investigator_full_name>
    <investigator_title>Clinical Professor</investigator_title>
  </responsible_party>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Altitude Sickness</mesh_term>
  </condition_browse>
  <patient_data>
    <sharing_ipd>No</sharing_ipd>
    <ipd_description>After the result publish online, the data will be shared.</ipd_description>
  </patient_data>
  <!-- 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/NCT04491500
org study id: 2020051
nct id: NCT04491500
lead sponsor: 
has dmc: No
is fda regulated drug: No
is fda regulated device: No
This is a prospective observational study. The purpose is to explore the effect of high
      altitude hypobaric hypoxia on retinal microcirculation and the change of the thickness of the
      retina and choroid by optical coherence tomography angiography (OCTA).
Yushu is in Qinghai-Tibet plateau, an average altitude of 4000 m. The medical staff is
      limited in Yushu. Zhongshan ophthalmic center, sun yat-sen university in Yushu blindness
      project has lasted many years. Some medical staff who arrived at Yushu will have a plateau
      response. The high altitude hypoxia on retinal microcirculation evaluated by OCTA has not
      been reported. The aim of the study is to observe the microcirculation changes after
      exploring a hypobaric and hypoxia environment using OCTA, and relation with the plateau
      response. OCTA is a non-invasive examination and could see the microcirculation of the fundus
      directly and quickly.
observational model: Other
time perspective: Prospective
measure: retinal microcirculation changes
time frame: 1 month
description: the vascular density measured by OCTA
measure: Retinal thickness changes
time frame: 1 month
description: the retinal thickness measured by OCTA
measure: Choroidal thickness changes
time frame: 1 month
description: the subfoveal choroidal thickness measured by OCTA
measure: The correlation of retinal microcirculation with the altitude illness
time frame: 1 month
description: The relationship between retinal vascular density as measured by OCTA and the degree of altitude illness as measured by acute mountain sickness (AMS) scoring system
measure: The changes of intraocular pressure
time frame: 1 month
description: The changes of intraocular pressure measured by icare Tonometer
measure: The changes of blood pressure including systolic and diastolic Blood Pressure
time frame: 1 month
description: The changes of blood pressure measured by Blood Pressure Meter
measure: The changes of blood oxygen
time frame: 1 month
description: The changes of blood Oxygen measured by Pulse Oximeter
measure: the degree of altitude illness
time frame: 1 month
description: the degree of altitude illness was assessed by acute mountain sickness (AMS) scoring system
arm group label: study group
description: This is a self-control study. Subjects who plan togo to 4000m altitude to work for two weeks will be enrolled. And before and after they arrive high altitude, they will have visual acuity, OCTA, and intraocular pressure; blood pressure, blood oxygen measurement.
intervention type: Behavioral
intervention name: High attitude environment
description: The participants will go to 4000m altitude to work for two weeks.
arm group label: study group
study pop: 
sampling method: Non-Probability Sample
criteria: 
gender: All
minimum age: 18 Years
maximum age: 70 Years
last name: Xiaoling Liang, M.D
role: Principal Investigator
affiliation: Zhongshan Ophthalmic Center, Sun Yat-sen University
facility: 
country: China
responsible party type: Principal Investigator
investigator affiliation: Zhongshan Ophthalmic Center, Sun Yat-sen University
investigator full name: Shanshan Yu, MD
investigator title: Clinical Professor
mesh term: Altitude Sickness
sharing ipd: No
ipd description: After the result publish online, the data will be shared.