Perceptual Learning Treatment for Amblyopia

Towards Developing a Perceptual Learning Treatment for Amblyopia

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

Study Overview

• Status: Completed
• Conditions: Amblyopia
• Intervention / Treatment: Other: Acuity training; Other: Occlusion therapy

• Study Type: Interventional
• Enrollment (Actual): 54
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Hong Kong
  • Hong Kong, Hong Kong
    • Optometry Research Clinic

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 7 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

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

Exclusion Criteria:

• Manifest eye disease & nystagmus

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Perceptual learning group - Amblyopia; Visual training	Other: Acuity training; 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.
Active Comparator: Perceptual learning group - Control; Visual training	Other: Acuity training; 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.
Placebo Comparator: Occlusion therapy - Amblyopia; Patching	Other: Occlusion therapy; Participants will be required to patch the good eye for 20 days, 1 hour per day.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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 Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change of visual acuity	Visual acuity tests the participants' ability to resolve letters.This study measures the change of visual acuity after 20 hours of vision training.	20 hours
Change of contrast sensitivity	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.	20 hours
Change of stereopsis	Visual acuity tests the 3-D perception. This study measures the change of stereopsis after 20 hours of vision training.	20 hours

Collaborators and Investigators

• Sponsor: The Hong Kong Polytechnic University
• Investigators: Principal Investigator: Tsz Wing Leung, Ph.D., The Hong Kong Polytechnic University

Publications and helpful links

General Publications

• 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.
• 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.
• 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.

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2019
• Primary Completion (Actual): December 31, 2022
• Study Completion (Actual): February 28, 2023

Study Registration Dates

• First Submitted: December 11, 2018
• First Submitted That Met QC Criteria: December 23, 2018
• First Posted (Actual): December 27, 2018

Study Record Updates

• Last Update Posted (Actual): August 29, 2024
• Last Update Submitted That Met QC Criteria: August 28, 2024
• Last Verified: August 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Eye Diseases; Neurologic Manifestations; Sensation Disorders; Vision Disorders; Amblyopia
• Other Study ID Numbers: HSEARS20171108002

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No