NCT03788031

Brief Summary

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

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
54

participants targeted

Target at P25-P50 for not_applicable

Timeline
Completed

Started Mar 2019

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

December 11, 2018

Completed
16 days until next milestone

First Posted

Study publicly available on registry

December 27, 2018

Completed
2 months until next milestone

Study Start

First participant enrolled

March 1, 2019

Completed
3.8 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 31, 2022

Completed
2 months until next milestone

Study Completion

Last participant's last visit for all outcomes

February 28, 2023

Completed
Last Updated

August 29, 2024

Status Verified

August 1, 2021

Enrollment Period

3.8 years

First QC Date

December 11, 2018

Last Update Submit

August 28, 2024

Conditions

Amblyopia

Outcome Measures

Primary Outcomes (1)

  • Change of grating acuity

    Grating acuity tests the participants' ability to resolve fine details. This study measures the change of grating acuity after 20 hours of vision training.

    20 hours

Secondary Outcomes (3)

  • Change of visual acuity

    20 hours

  • Change of contrast sensitivity

    20 hours

  • Change of stereopsis

    20 hours

Study Arms (3)

Perceptual learning group - Amblyopia

EXPERIMENTAL

Visual training

Other: Acuity training

Perceptual learning group - Control

ACTIVE COMPARATOR

Visual training

Other: Acuity training

Occlusion therapy - Amblyopia

PLACEBO COMPARATOR

Patching

Other: Occlusion therapy

Interventions

Acuity trainingOTHER

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.

Perceptual learning group - AmblyopiaPerceptual learning group - Control
Occlusion therapyOTHER

Participants will be required to patch the good eye for 20 days, 1 hour per day.

Occlusion therapy - Amblyopia

Eligibility Criteria

Age7 Years+
Sexall
Healthy VolunteersYes
Age GroupsChild (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

  • Visual acuity in the amblyopic eye: 20/25 or worse

You may not qualify if:

  • Manifest eye disease \& nystagmus

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Optometry Research Clinic

Hong Kong, Hong Kong

Location

Related Publications (3)

  • 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: 19008199RESULT

  • 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: 19109504RESULT

  • 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: 21912514RESULT

MeSH Terms

Conditions

Amblyopia

Condition Hierarchy (Ancestors)

Brain DiseasesCentral Nervous System DiseasesNervous System DiseasesVision DisordersSensation DisordersNeurologic ManifestationsEye DiseasesSigns and SymptomsPathological Conditions, Signs and Symptoms

Study Officials

  • Tsz Wing Leung, Ph.D.

    The Hong Kong Polytechnic University

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NON RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

December 11, 2018

First Posted

December 27, 2018

Study Start

March 1, 2019

Primary Completion

December 31, 2022

Study Completion

February 28, 2023

Last Updated

August 29, 2024

Record last verified: 2021-08

Locations

HK(1)