Establishing New Treatment Approaches for Amblyopia: Perceptual Learning and Video Games

Improving Normal and Amblyopic Vision With Video Games and Perceptual Learning

Amblyopia, a developmental abnormality that impairs spatial vision, is a major cause of vision loss, resulting in reduced visual acuity and reduced sensitivity to contrast. This study uses psychophysical measures to study neural plasticity in both adults and children with amblyopia.

Study Overview

• Status: Recruiting
• Conditions: Amblyopia
• Intervention / Treatment: Behavioral: Video Game Vision Training; Behavioral: Perceptual Learning; Behavioral: Occlusion Therapy

Detailed Description

Amblyopia, a developmental abnormality that impairs spatial vision, is a major cause of vision loss, resulting in reduced visual acuity and reduced sensitivity to contrast. Our previous findings (see Publications) show that the adult amblyopic brain is still plastic and malleable, suggesting that active approach is potential useful in treating amblyopia.The goal of this project is to assess the limits and mechanisms of neural plasticity in both normal and amblyopic spatial vision. This study uses psychophysical measures to study neural plasticity in both adults and children with amblyopia. Research participants will be asked to practice a visual discrimination task (perceptual learning) or to play video games with the amblyopic eye for a period of time. A range of visual functions will be monitored during the course of treatment.

• Study Type: Interventional
• Enrollment (Estimated): 180
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Roger W Li, OD, PhD; Phone Number: 954-262-1436; Email: wli@nova.edu

Study Locations

• United States
  • Florida
    • Fort Lauderdale, Florida, United States, 33328
      • Recruiting
      • Nova Southeastern University College of Optometry
      • Contact: Roger Li, OD, PhD; Phone Number: 954-262-1436; Email: wli@nova.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• adults and children with normal vision or amblyopia
• amblyopia: interocular VA difference of 0.1 logMAR or more

Exclusion Criteria:

• any ocular pathological conditions, nystagmus

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Video Games; Participants will be required to play video games for a period of time: 1-2 hrs per session, 4-5 sessions/week for ~1-6 months	Behavioral: Video Game Vision Training; A new approach for improving amblyopic vision using video games
Experimental: Perceptual learning; Participants will be required to practice a visual discrimination task (e.g. visual acuity, position acuity, contrast sensitivity, & stereoacuity) for a period of time: 1-2 hrs per session, 4-5 sessions/week for ~1-6 months	Behavioral: Perceptual Learning; A new approach for improving amblyopic vision with perceptual learning
Active Comparator: Occlusion therapy; Participants will be required to cover the dominant eye during the day in order to push the brain to use the fellow amblyopic eye: 1-2 hrs per session, 4-5 sessions/week for ~1-6 months	Behavioral: Occlusion Therapy; Conventional treatment for amblyopia

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in visual acuity before and after the intervention	"Visual acuity", the gold standard for vision testing, will be measured. Participants will be asked to read letters on a LogMAR letter chart. The smallest letters that can be read correspond to visual acuity (e.g., Snellen acuity of 20/20, letter-stroke width = 1 minute of arc).	9 months
Change in stereoacuity before and after the intervention	"Stereoacuity" will be measured psychophysically using a new stereoacuity function test (1.25, 2.5, 5, 10, 15, & 20 cycles per degree) developed in our previous studies (Li et al 2016). A custom-built 4-mirror haploscope will be used to present a stereogram to each eye. Stereoacuity is the smallest stereo disparity that can be seen in binocular vision (in the unit of seconds of arc, arcsec). The conventional stereoacuity tests (including Randot Stereoacuity Test, Stereofly Test & Preschool Stereo Test) will also be used to measure stereoacuity. Participants will be asked to wear a pair of 3D glasses and to identify the target 3D pictures at various 3D levels. The smallest 3D disparities that can be seen correspond to stereoacuity (e.g. normal range of stereoacuity: 50 seconds of arc or better).	9 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in contrast sensitivity before and after the intervention	"Contrast sensitivity", the ability to detect low contrast / brightness, will be measured psychophysically for a range of spatial frequencies (1.25, 2.5, 5, 10, & 20 cycles per degree). Visual stimuli at different contrast levels will be displayed on a monitor screen. The smallest detectable stimulus contrast level will be measured in the unit of cd/m2.	9 months
Change in positional (or Vernier) acuity before and after the intervention	"Positional acuity", the ability to detect a subtle positional offset between visual stimuli, will be measured psychophysically. Visual stimuli with different amount of positional offsets will be displayed on a monitor screen. The smallest detectable stimulus offset will be measured as position acuity, in the unit of seconds of arc.	9 months

Collaborators and Investigators

• Sponsor: Nova Southeastern University
• Investigators: Principal Investigator: Roger W Li, OD, PhD, Nova Southeastern University College of Optometry

Publications and helpful links

General Publications

• Li RW, Tran KD, Bui JK, Antonucci MM, Ngo CV, Levi DM. Improving Adult Amblyopic Vision with Stereoscopic 3-Dimensional Video Games. Ophthalmology. 2018 Oct;125(10):1660-1662. doi: 10.1016/j.ophtha.2018.04.025. Epub 2018 May 18. No abstract available.
• Li RW, So K, Wu TH, Craven AP, Tran TT, Gustafson KM, Levi DM. Monocular blur alters the tuning characteristics of stereopsis for spatial frequency and size. R Soc Open Sci. 2016 Sep 21;3(9):160273. doi: 10.1098/rsos.160273. eCollection 2016 Sep.
• 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.
• Li RW, Levi DM. Characterizing the mechanisms of improvement for position discrimination in adult amblyopia. J Vis. 2004 Jun 1;4(6):476-87. doi: 10.1167/4.6.7.
• 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, Provost A, Levi DM. Extended perceptual learning results in substantial recovery of positional acuity and visual acuity in juvenile amblyopia. Invest Ophthalmol Vis Sci. 2007 Nov;48(11):5046-51. doi: 10.1167/iovs.07-0324.
• Li RW, Young KG, Hoenig P, Levi DM. Perceptual learning improves visual performance in juvenile amblyopia. Invest Ophthalmol Vis Sci. 2005 Sep;46(9):3161-8. doi: 10.1167/iovs.05-0286.
• Li RW, Ngo CV, Levi DM. Relieving the attentional blink in the amblyopic brain with video games. Sci Rep. 2015 Feb 26;5:8483. doi: 10.1038/srep08483.
• Li RW, Tran TT, Craven AP, Leung TW, Chat SW, Levi DM. Sharpening coarse-to-fine stereo vision by perceptual learning: asymmetric transfer across the spatial frequency spectrum. R Soc Open Sci. 2016 Jan 20;3(1):150523. doi: 10.1098/rsos.150523. eCollection 2016 Jan.
• Li RW, Levi DM, Klein SA. Perceptual learning improves efficiency by re-tuning the decision 'template' for position discrimination. Nat Neurosci. 2004 Feb;7(2):178-83. doi: 10.1038/nn1183. Epub 2004 Jan 18.
• Leung TW, Li RW, Kee CS. Brief Adaptation to Astigmatism Reduces Meridional Anisotropy in Contrast Sensitivity. Invest Ophthalmol Vis Sci. 2023 Sep 1;64(12):4. doi: 10.1167/iovs.64.12.4.

Study record dates

Study Major Dates

• Study Start (Actual): September 13, 2022
• Primary Completion (Estimated): August 31, 2028
• Study Completion (Estimated): August 31, 2028

Study Registration Dates

• First Submitted: August 24, 2022
• First Submitted That Met QC Criteria: August 29, 2022
• First Posted (Actual): August 31, 2022

Study Record Updates

• Last Update Posted (Estimated): November 9, 2023
• Last Update Submitted That Met QC Criteria: November 7, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Keywords: strabismus; video games; perceptual learning; stereoacuity; amblyopia treatment; visual plasticity; pathophysiology of amblyopia; vision training
• 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: 2022-344

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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