<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/NCT03788031</url>
  </required_header>
  <id_info>
    <org_study_id>HSEARS20171108002</org_study_id>
    <nct_id>NCT03788031</nct_id>
  </id_info>
  <brief_title>Perceptual Learning Treatment for Amblyopia</brief_title>
  <official_title>Towards Developing a Perceptual Learning Treatment for Amblyopia</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>The Hong Kong Polytechnic University</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>The Hong Kong Polytechnic University</source>
  <oversight_info>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      Objectives. To develop a new treatment for amblyopia using a perceptual learning approach.&#xD;
&#xD;
      Hypothesis to be tested. Our proposed experiments are designed to investigate whether&#xD;
      practicing a grating detection task can improve vision in patients with amblyopia.&#xD;
&#xD;
      Design and subjects. A total of 36 patients with amblyopia will be randomized allocated into&#xD;
      two intervention groups: Group 1, perceptual learning therapy. Group 2, occlusion therapy. A&#xD;
      control group comprising of 18 subjects with normal vision will be recruited for comparison.&#xD;
      A battery of tests will be used to assess a range of visual functions before and after the&#xD;
      treatment intervention.&#xD;
&#xD;
      Study instruments. Grating acuity testing system&#xD;
&#xD;
      Interventions. We have established a clinical protocol for acuity training. On each trial, a&#xD;
      properly oriented stimulus will be presented randomly at one of the four locations on a flat&#xD;
      monitor screen. The visual task is to indicate the location of the stimulus. Participants&#xD;
      will be required to undertake 20 one-hour sessions of training.&#xD;
&#xD;
      Main outcome measures. Resolution acuity, visual acuity, contrast sensitivity function&#xD;
    </textblock>
  </brief_summary>
  <overall_status>Unknown status</overall_status>
  <last_known_status>Active, not recruiting</last_known_status>
  <start_date type="Actual">March 1, 2019</start_date>
  <completion_date type="Anticipated">February 28, 2023</completion_date>
  <primary_completion_date type="Anticipated">December 31, 2022</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>Non-Randomized</allocation>
    <intervention_model>Parallel Assignment</intervention_model>
    <primary_purpose>Treatment</primary_purpose>
    <masking>None (Open Label)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>Change of grating acuity</measure>
    <time_frame>20 hours</time_frame>
    <description>Grating acuity tests the participants' ability to resolve fine details. This study measures the change of grating acuity after 20 hours of vision training.</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Change of visual acuity</measure>
    <time_frame>20 hours</time_frame>
    <description>Visual acuity tests the participants' ability to resolve letters.This study measures the change of visual acuity after 20 hours of vision training.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Change of contrast sensitivity</measure>
    <time_frame>20 hours</time_frame>
    <description>Contrast sensitivity reflects the participants' sensitivity to identify low contrast visual stimuli. This study measures the change of contrast sensitivity after 20 hours of vision training.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Change of stereopsis</measure>
    <time_frame>20 hours</time_frame>
    <description>Visual acuity tests the 3-D perception. This study measures the change of stereopsis after 20 hours of vision training.</description>
  </secondary_outcome>
  <number_of_arms>3</number_of_arms>
  <enrollment type="Anticipated">54</enrollment>
  <condition>Amblyopia</condition>
  <arm_group>
    <arm_group_label>Perceptual learning group - Amblyopia</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
    <description>Visual training</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Perceptual learning group - Control</arm_group_label>
    <arm_group_type>Active Comparator</arm_group_type>
    <description>Visual training</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Occlusion therapy - Amblyopia</arm_group_label>
    <arm_group_type>Placebo Comparator</arm_group_type>
    <description>Patching</description>
  </arm_group>
  <intervention>
    <intervention_type>Other</intervention_type>
    <intervention_name>Acuity training</intervention_name>
    <description>The intervention will be a vision therapy. On each trial, a properly oriented stimulus will be presented randomly at one of the four locations on a flat monitor screen. The visual task is to identify the location of the stimulus.</description>
    <arm_group_label>Perceptual learning group - Amblyopia</arm_group_label>
    <arm_group_label>Perceptual learning group - Control</arm_group_label>
  </intervention>
  <intervention>
    <intervention_type>Other</intervention_type>
    <intervention_name>Occlusion therapy</intervention_name>
    <description>Participants will be required to patch the good eye for 20 days, 1 hour per day.</description>
    <arm_group_label>Occlusion therapy - Amblyopia</arm_group_label>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Visual acuity in the amblyopic eye: 20/25 or worse&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Manifest eye disease &amp; nystagmus&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>7 Years</minimum_age>
    <maximum_age>N/A</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Tsz Wing Leung, Ph.D.</last_name>
    <role>Principal Investigator</role>
    <affiliation>The Hong Kong Polytechnic University</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Optometry Research Clinic</name>
      <address>
        <city>Hong Kong</city>
        <country>Hong Kong</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>Hong Kong</country>
  </location_countries>
  <results_reference>
    <citation>Levi DM, Li RW. Improving the performance of the amblyopic visual system. Philos Trans R Soc Lond B Biol Sci. 2009 Feb 12;364(1515):399-407. doi: 10.1098/rstb.2008.0203.</citation>
    <PMID>19008199</PMID>
  </results_reference>
  <results_reference>
    <citation>Li RW, Klein SA, Levi DM. Prolonged perceptual learning of positional acuity in adult amblyopia: perceptual template retuning dynamics. J Neurosci. 2008 Dec 24;28(52):14223-9. doi: 10.1523/JNEUROSCI.4271-08.2008.</citation>
    <PMID>19109504</PMID>
  </results_reference>
  <results_reference>
    <citation>Li RW, Ngo C, Nguyen J, Levi DM. Video-game play induces plasticity in the visual system of adults with amblyopia. PLoS Biol. 2011 Aug;9(8):e1001135. doi: 10.1371/journal.pbio.1001135. Epub 2011 Aug 30.</citation>
    <PMID>21912514</PMID>
  </results_reference>
  <verification_date>August 2021</verification_date>
  <study_first_submitted>December 11, 2018</study_first_submitted>
  <study_first_submitted_qc>December 23, 2018</study_first_submitted_qc>
  <study_first_posted type="Actual">December 27, 2018</study_first_posted>
  <last_update_submitted>August 24, 2021</last_update_submitted>
  <last_update_submitted_qc>August 24, 2021</last_update_submitted_qc>
  <last_update_posted type="Actual">August 26, 2021</last_update_posted>
  <responsible_party>
    <responsible_party_type>Sponsor</responsible_party_type>
  </responsible_party>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Amblyopia</mesh_term>
  </condition_browse>
  <patient_data>
    <sharing_ipd>Undecided</sharing_ipd>
  </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/NCT03788031
org study id: HSEARS20171108002
nct id: NCT03788031
lead sponsor: 
is fda regulated drug: No
is fda regulated device: No
Objectives. To develop a new treatment for amblyopia using a perceptual learning approach.

      Hypothesis to be tested. Our proposed experiments are designed to investigate whether
      practicing a grating detection task can improve vision in patients with amblyopia.

      Design and subjects. A total of 36 patients with amblyopia will be randomized allocated into
      two intervention groups: Group 1, perceptual learning therapy. Group 2, occlusion therapy. A
      control group comprising of 18 subjects with normal vision will be recruited for comparison.
      A battery of tests will be used to assess a range of visual functions before and after the
      treatment intervention.

      Study instruments. Grating acuity testing system

      Interventions. We have established a clinical protocol for acuity training. On each trial, a
      properly oriented stimulus will be presented randomly at one of the four locations on a flat
      monitor screen. The visual task is to indicate the location of the stimulus. Participants
      will be required to undertake 20 one-hour sessions of training.

      Main outcome measures. Resolution acuity, visual acuity, contrast sensitivity function
allocation: Non-Randomized
intervention model: Parallel Assignment
primary purpose: Treatment
masking: None (Open Label)
measure: Change of grating acuity
time frame: 20 hours
description: Grating acuity tests the participants' ability to resolve fine details. This study measures the change of grating acuity after 20 hours of vision training.
measure: Change of visual acuity
time frame: 20 hours
description: Visual acuity tests the participants' ability to resolve letters.This study measures the change of visual acuity after 20 hours of vision training.
measure: Change of contrast sensitivity
time frame: 20 hours
description: Contrast sensitivity reflects the participants' sensitivity to identify low contrast visual stimuli. This study measures the change of contrast sensitivity after 20 hours of vision training.
measure: Change of stereopsis
time frame: 20 hours
description: Visual acuity tests the 3-D perception. This study measures the change of stereopsis after 20 hours of vision training.
arm group label: Perceptual learning group - Amblyopia
arm group type: Experimental
description: Visual training
arm group label: Perceptual learning group - Control
arm group type: Active Comparator
description: Visual training
arm group label: Occlusion therapy - Amblyopia
arm group type: Placebo Comparator
description: Patching
intervention type: Other
intervention name: Acuity training
description: The intervention will be a vision therapy. On each trial, a properly oriented stimulus will be presented randomly at one of the four locations on a flat monitor screen. The visual task is to identify the location of the stimulus.
arm group label: Perceptual learning group - Amblyopia
arm group label: Perceptual learning group - Control
intervention type: Other
intervention name: Occlusion therapy
description: Participants will be required to patch the good eye for 20 days, 1 hour per day.
arm group label: Occlusion therapy - Amblyopia
criteria: 
gender: All
minimum age: 7 Years
maximum age: N/A
healthy volunteers: Accepts Healthy Volunteers
last name: Tsz Wing Leung, Ph.D.
role: Principal Investigator
affiliation: The Hong Kong Polytechnic University
facility: 
country: Hong Kong
citation: Levi DM, Li RW. Improving the performance of the amblyopic visual system. Philos Trans R Soc Lond B Biol Sci. 2009 Feb 12;364(1515):399-407. doi: 10.1098/rstb.2008.0203.
PMID: 19008199
citation: Li RW, Klein SA, Levi DM. Prolonged perceptual learning of positional acuity in adult amblyopia: perceptual template retuning dynamics. J Neurosci. 2008 Dec 24;28(52):14223-9. doi: 10.1523/JNEUROSCI.4271-08.2008.
PMID: 19109504
citation: Li RW, Ngo C, Nguyen J, Levi DM. Video-game play induces plasticity in the visual system of adults with amblyopia. PLoS Biol. 2011 Aug;9(8):e1001135. doi: 10.1371/journal.pbio.1001135. Epub 2011 Aug 30.
PMID: 21912514
responsible party type: Sponsor
mesh term: Amblyopia
sharing ipd: Undecided