<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/NCT04495491</url>
  </required_header>
  <id_info>
    <org_study_id>2019KYPJ182</org_study_id>
    <nct_id>NCT04495491</nct_id>
  </id_info>
  <brief_title>Predicting the Effect of Laser Peripheral Iridotomy</brief_title>
  <official_title>Prediction of the Degree of Angle Opening Distance in Patients With Primary Angle Closure Suspect After Laser Peripheral Iridotomy</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 study will compare the angle parameters of patients with PACS before and after LPI. The&#xD;
      investigators will analyze the results of patients with different angle closure mechanisms&#xD;
      before and after LPI, and participants hope to find the structural parameters for predicting&#xD;
      the effect of LPI.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Primary angle-closure glaucoma is the leading cause of blindness worldwide. It is associated&#xD;
      with increased intraocular pressure, which causes optic nerve damage and field defects if&#xD;
      untreated. The aqueous humor leaves the anterior chamber through the trabecular meshwork and&#xD;
      flows into the aqueous vein and the superior scleral vein through the collector channels and&#xD;
      Schlemm's canal. If the trabecular meshwork is not blocked, a wide angle allows enough&#xD;
      aqueous humor to drain out. The iris corneal translocation may lead to angle-closure&#xD;
      glaucoma.&#xD;
&#xD;
      Laser peripheral iridectomy is recognized as the best surgical method to relieve pupil block.&#xD;
      Previous studies have shown increased anterior chamber depth (ACD), area (ACA), and volume&#xD;
      (ACV), and increased Angle open distance (AOD) after LPI surgery.&#xD;
&#xD;
      However, postoperative outcomes of LPI were not the same for patients with different angle&#xD;
      closure mechanisms.&#xD;
&#xD;
      Postoperative outcomes for LPI were best for patients with pupillary block type, but were&#xD;
      moderate for patients with plateau iris group and mixed group.&#xD;
&#xD;
      The purpose of this study, conducted in Chinese subjects, aims to use UBM to evaluate changes&#xD;
      in the anterior segment parameters of LPI, and to propose methods to predict postoperative&#xD;
      outcomes of LPI.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Unknown status</overall_status>
  <last_known_status>Recruiting</last_known_status>
  <start_date type="Actual">July 1, 2020</start_date>
  <completion_date type="Anticipated">March 31, 2021</completion_date>
  <primary_completion_date type="Anticipated">December 31, 2020</primary_completion_date>
  <study_type>Observational [Patient Registry]</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>
  <target_duration>4 Weeks</target_duration>
  <primary_outcome>
    <measure>the changes in anterior opening distance before and after LPI</measure>
    <time_frame>between the baseline and 1 hour before discharge</time_frame>
    <description>To compare the difference of anterior opening distance after LPI and baseline parameters before LPI. Anterior opening distance, measured on a line perpendicular to the plane of the trabecular surface 500 μm anterior to the scleral spur and extended to meet the surface of the iris</description>
  </primary_outcome>
  <number_of_groups>3</number_of_groups>
  <enrollment type="Anticipated">200</enrollment>
  <condition>Glaucoma</condition>
  <arm_group>
    <arm_group_label>Pupillary block group</arm_group_label>
    <description>According to the configurations of angle closure, the pupillary block group is defined as the iris bombe.</description>
  </arm_group>
  <arm_group>
    <arm_group_label>plateau iris group</arm_group_label>
    <description>According to the configurations of angle closure, the plateau iris group is defined as the thickness of the peripheral iris.</description>
  </arm_group>
  <arm_group>
    <arm_group_label>mixed mechanism group</arm_group_label>
    <description>According to the configurations of angle closure, the mixing mechanism group is defined as the iris bombe plus thickening of the peripheral iris.</description>
  </arm_group>
  <intervention>
    <intervention_type>Other</intervention_type>
    <intervention_name>pupillary block group</intervention_name>
    <description>According to the configurations of angle closure, the pupillary block group is defined as the iris bombe.</description>
    <arm_group_label>Pupillary block group</arm_group_label>
  </intervention>
  <intervention>
    <intervention_type>Other</intervention_type>
    <intervention_name>plateau iris group</intervention_name>
    <description>According to the configurations of angle closure, the plateau iris group is defined as the thickness of the peripheral iris.</description>
    <arm_group_label>plateau iris group</arm_group_label>
  </intervention>
  <intervention>
    <intervention_type>Other</intervention_type>
    <intervention_name>mixing mechanism group</intervention_name>
    <description>According to the configurations of angle closure, the mixing mechanism group is defined as the iris bombe plus thickening of the peripheral iris.</description>
    <arm_group_label>mixed mechanism group</arm_group_label>
  </intervention>
  <eligibility>
    <study_pop>
      <textblock>
        Chinese Patient was diagnosed of primary angle closure angle suspect&#xD;
      </textblock>
    </study_pop>
    <sampling_method>Non-Probability Sample</sampling_method>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          1. Patient was diagnosed of primary angle closure angle suspect;&#xD;
&#xD;
          2. received ultrasound Biomicroscopy before and after laser peripheral iridotomy;&#xD;
&#xD;
          3. Voluntary participation in this study;&#xD;
&#xD;
          4. Have enough language comprehension ability;&#xD;
&#xD;
          5. Patient or his legal representative has sign the informed consent.&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          1. severe health problems resulting in a life expectancy of less than 1 year;&#xD;
&#xD;
          2. previous intraocular surgery or penetrating eye injury;&#xD;
&#xD;
          3. media opacity preventing laser peripheral iridotomy;&#xD;
&#xD;
          4. Researchers think not suitable to participate in this clinical trial subjects;&#xD;
&#xD;
          5. Refused to sign the informed consent.;&#xD;
&#xD;
          6. There are important viscera function failure or other serious disease, including&#xD;
             clinical related coronary artery disease, cardiovascular disease or myocardial&#xD;
             infarction into the group of the first six months; serious neurological or psychiatric&#xD;
             illness; serious infections; coagulant function abnormality; general active infectious&#xD;
             diseases; malignant tumor; serious immune diseases.&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>20 Years</minimum_age>
    <maximum_age>N/A</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Mingkai Lin, MD</last_name>
    <role>Study Chair</role>
    <affiliation>Zhongshan Ophthalmic Center, Sun Yat-San University</affiliation>
  </overall_official>
  <overall_contact>
    <last_name>Yuying Zhou, Master</last_name>
    <phone>8615270988097</phone>
    <email>2053552500@qq.com</email>
  </overall_contact>
  <location>
    <facility>
      <name>Zhongshan Ophthalmic Center, Sun Yat-San Univerdity</name>
      <address>
        <city>Guangzhou</city>
        <state>Guangdong</state>
        <country>China</country>
      </address>
    </facility>
    <status>Recruiting</status>
    <contact>
      <last_name>Yuying Zhou, Master</last_name>
      <phone>15270988097</phone>
      <email>2053552500@qq.com</email>
    </contact>
  </location>
  <location_countries>
    <country>China</country>
  </location_countries>
  <reference>
    <citation>He M, Jiang Y, Huang S, Chang DS, Munoz B, Aung T, Foster PJ, Friedman DS. Laser peripheral iridotomy for the prevention of angle closure: a single-centre, randomised controlled trial. Lancet. 2019 Apr 20;393(10181):1609-1618. doi: 10.1016/S0140-6736(18)32607-2. Epub 2019 Mar 14.</citation>
    <PMID>30878226</PMID>
  </reference>
  <reference>
    <citation>He M, Friedman DS, Ge J, Huang W, Jin C, Lee PS, Khaw PT, Foster PJ. Laser peripheral iridotomy in primary angle-closure suspects: biometric and gonioscopic outcomes: the Liwan Eye Study. Ophthalmology. 2007 Mar;114(3):494-500. doi: 10.1016/j.ophtha.2006.06.053. Epub 2006 Nov 21.</citation>
    <PMID>17123610</PMID>
  </reference>
  <reference>
    <citation>He M, Foster PJ, Ge J, Huang W, Zheng Y, Friedman DS, Lee PS, Khaw PT. Prevalence and clinical characteristics of glaucoma in adult Chinese: a population-based study in Liwan District, Guangzhou. Invest Ophthalmol Vis Sci. 2006 Jul;47(7):2782-8. doi: 10.1167/iovs.06-0051.</citation>
    <PMID>16799014</PMID>
  </reference>
  <verification_date>July 2020</verification_date>
  <study_first_submitted>July 22, 2020</study_first_submitted>
  <study_first_submitted_qc>July 28, 2020</study_first_submitted_qc>
  <study_first_posted type="Actual">July 31, 2020</study_first_posted>
  <last_update_submitted>July 28, 2020</last_update_submitted>
  <last_update_submitted_qc>July 28, 2020</last_update_submitted_qc>
  <last_update_posted type="Actual">July 31, 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>Mingkai Lin</investigator_full_name>
    <investigator_title>chief physician</investigator_title>
  </responsible_party>
  <keyword>laser peripheral iridotomy</keyword>
  <keyword>primary angle closure suspect</keyword>
  <keyword>angle closure mechanism</keyword>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Glaucoma</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/NCT04495491
org study id: 2019KYPJ182
nct id: NCT04495491
lead sponsor: 
has dmc: No
is fda regulated drug: No
is fda regulated device: No
This study will compare the angle parameters of patients with PACS before and after LPI. The
      investigators will analyze the results of patients with different angle closure mechanisms
      before and after LPI, and participants hope to find the structural parameters for predicting
      the effect of LPI.
Primary angle-closure glaucoma is the leading cause of blindness worldwide. It is associated
      with increased intraocular pressure, which causes optic nerve damage and field defects if
      untreated. The aqueous humor leaves the anterior chamber through the trabecular meshwork and
      flows into the aqueous vein and the superior scleral vein through the collector channels and
      Schlemm's canal. If the trabecular meshwork is not blocked, a wide angle allows enough
      aqueous humor to drain out. The iris corneal translocation may lead to angle-closure
      glaucoma.

      Laser peripheral iridectomy is recognized as the best surgical method to relieve pupil block.
      Previous studies have shown increased anterior chamber depth (ACD), area (ACA), and volume
      (ACV), and increased Angle open distance (AOD) after LPI surgery.

      However, postoperative outcomes of LPI were not the same for patients with different angle
      closure mechanisms.

      Postoperative outcomes for LPI were best for patients with pupillary block type, but were
      moderate for patients with plateau iris group and mixed group.

      The purpose of this study, conducted in Chinese subjects, aims to use UBM to evaluate changes
      in the anterior segment parameters of LPI, and to propose methods to predict postoperative
      outcomes of LPI.
observational model: Other
time perspective: Prospective
measure: the changes in anterior opening distance before and after LPI
time frame: between the baseline and 1 hour before discharge
description: To compare the difference of anterior opening distance after LPI and baseline parameters before LPI. Anterior opening distance, measured on a line perpendicular to the plane of the trabecular surface 500 μm anterior to the scleral spur and extended to meet the surface of the iris
arm group label: Pupillary block group
description: According to the configurations of angle closure, the pupillary block group is defined as the iris bombe.
arm group label: plateau iris group
description: According to the configurations of angle closure, the plateau iris group is defined as the thickness of the peripheral iris.
arm group label: mixed mechanism group
description: According to the configurations of angle closure, the mixing mechanism group is defined as the iris bombe plus thickening of the peripheral iris.
intervention type: Other
intervention name: pupillary block group
description: According to the configurations of angle closure, the pupillary block group is defined as the iris bombe.
arm group label: Pupillary block group
intervention type: Other
intervention name: plateau iris group
description: According to the configurations of angle closure, the plateau iris group is defined as the thickness of the peripheral iris.
arm group label: plateau iris group
intervention type: Other
intervention name: mixing mechanism group
description: According to the configurations of angle closure, the mixing mechanism group is defined as the iris bombe plus thickening of the peripheral iris.
arm group label: mixed mechanism group
study pop: 
sampling method: Non-Probability Sample
criteria: 
gender: All
minimum age: 20 Years
maximum age: N/A
healthy volunteers: No
last name: Mingkai Lin, MD
role: Study Chair
affiliation: Zhongshan Ophthalmic Center, Sun Yat-San University
last name: Yuying Zhou, Master
phone: 8615270988097
email: 2053552500@qq.com
facility: 
status: Recruiting
contact: 
country: China
citation: He M, Jiang Y, Huang S, Chang DS, Munoz B, Aung T, Foster PJ, Friedman DS. Laser peripheral iridotomy for the prevention of angle closure: a single-centre, randomised controlled trial. Lancet. 2019 Apr 20;393(10181):1609-1618. doi: 10.1016/S0140-6736(18)32607-2. Epub 2019 Mar 14.
PMID: 30878226
citation: He M, Friedman DS, Ge J, Huang W, Jin C, Lee PS, Khaw PT, Foster PJ. Laser peripheral iridotomy in primary angle-closure suspects: biometric and gonioscopic outcomes: the Liwan Eye Study. Ophthalmology. 2007 Mar;114(3):494-500. doi: 10.1016/j.ophtha.2006.06.053. Epub 2006 Nov 21.
PMID: 17123610
citation: He M, Foster PJ, Ge J, Huang W, Zheng Y, Friedman DS, Lee PS, Khaw PT. Prevalence and clinical characteristics of glaucoma in adult Chinese: a population-based study in Liwan District, Guangzhou. Invest Ophthalmol Vis Sci. 2006 Jul;47(7):2782-8. doi: 10.1167/iovs.06-0051.
PMID: 16799014
responsible party type: Principal Investigator
investigator affiliation: Zhongshan Ophthalmic Center, Sun Yat-sen University
investigator full name: Mingkai Lin
investigator title: chief physician
mesh term: Glaucoma