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Completed

NCT Number: NCT02995174

Will Perceptual Learning Via Video Game Playing Improve Visual Acuity Stereopsis & Fixation Stability in Mild Amblyopes?

Contrast balanced dichoptic videogame training has been found to improve sensory functions in adults with amblyopia; best corrected distance visual acuity (BCVA) and stereopsis, but its effect on motor function, namely amblyopic eye fixation stability, is unknown. Furthermore, the effect of treatment in cases of mild amblyopia is not well understood. The aim of this study is to find out the difference on fixation stability, BCVA and stereopsis in mild amblyopes after 6 weeks' contrast balanced dichoptic video game training.

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Key information

Conditions

Amblyopia Brain Diseases Central Nervous System Diseases Eye Diseases Nervous System Diseases Neurologic Manifestations Pathological Conditions, Signs and Symptoms Sensation Disorders Signs and Symptoms Vision Disorders

Age range

7 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

The Hong Kong Polytechnic University

Hong Kong

About this study

Objectives: To assess the change of fixation stability as well as visual acuity and stereopsis before and after training mild amblyopia by perceptual learning through dichoptic video game playing.

Hypothesis: It has been shown that the visual acuity, stereopsis and fixation stability are compromised in amblyopic eye. Perceptual learning via video game playing has been found effective in improving visual acuity and stereoacuity in moderate and severe amblyopic eyes, but there is no study on such treatment in mild amblyopia. In this study, we hypothesize that fixation stability, visual acuity and stereopsis will be improved after training by dichoptic video game playing in mild amblyopia.

Methods: Participants (aged 7 or above) with Best Corrected Visual Acuity (BCVA) ≤ 0.28 logMAR in the amblyopic eye and an interocular acuity difference ≥ 0.2 logMAR will be recruited. An anaglyphic, contrast balanced dichoptic video game will be provided on an i-Pod Touch (Apple Inc.) for 6 weeks of home-based training (60 mins per day). Fixation stability quantified using bivariate contour ellipse area (BCEA by micro-perimeter (MP) Nidek MP-1), BCVA and stereopsis will be assessed before and after treatment.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Best corrected VA in amblyopic eye ≤ 0.28 log MAR, fellow eye VA with an interocular VA difference ≥ 0.20 log MAR;
  • Amblyopia could be in form of strabismic, anisometropic and mixed (both strabismic and anisometropic)
  • Able to complete 3 successful measurements (each with 30 seconds fixation) of BCEA by the MP-1 systems in each eye
  • Able to align the nonius cross (≤10mm horizontal error and 5mm vertical error) in the i-Pod game

Exclusion criteria

  • Myopia of spherical equivalent power > -6.0 diopter in either eye
  • Previous intraocular surgery
  • any types of ocular pathology (e.g. media opacities or retinal lesion)
  • Previous or current history of neurological problem

Treatment and study plan

Dichoptic video game in an i-Pod touch device

Device

Amblyope will wear a pair of red green goggles and play the video game with 'contrast-balanced' images displayed on the screen of an i-Pod touch device. The eye with weaker eyesight will see the image with high contrast, and the good eye will see the image with low contrast. The subject will play the game one hour per day for 6 weeks.

Video game in an i-Pod touch device

Device

Amblyope will wear a pair of red green goggles and play the video game with equal contrast images displayed on the screen of an i-Pod touch device. Both eyes will see the image of same contrast. The subject will play the game one hour per day for 6 weeks.

Primary outcomes

  1. Change in fixation stability (in terms of Bivariate contour ellipse area in degree square) in the amblyopic eye after 6 weeks dichoptic video game playing in mild amblyopes

    Time frame: 6 weeks

    Change in fixation stability (in terms of Bivariate contour ellipse area in degree square) in the amblyopic eye after 6 weeks dichoptic video game playing in mild amblyopes. The 95% bivariate contour ellipse area will be adopted in units of degree square.

Secondary outcomes

  1. Change in best corrected visual acuity (in log MAR) in the amblyopic eye after 6 weeks dichoptic video game playing in mild amblyopes

    Time frame: 6 weeks

    Change in best corrected visual acuity (in log MAR) in the amblyopic eye after 6 weeks dichoptic video game playing in mild amblyopes. Best corrected visual acuity will be measured in log MAR unit.

  2. Change in stereopsis (in arc sec) after 6 weeks dichoptic video game playing in mild amblyopes

    Time frame: 6 weeks

    Change in stereopsis (in arc sec) after 6 weeks dichoptic video game playing in mild amblyopes. The Titmus and Randot preschool stereopsis test will be used and the measurements are recorded in ' second of arc'.

Sponsors and collaborators

Lead sponsor

The Hong Kong Polytechnic University

Other

Registry information

Official study title

Will Perceptual Learning Via Video Game Playing Improve Visual Acuity, Stereopsis and Fixation Stability in Mild Amblyopes? Part 2 Study

Important dates

Study start
2015
Primary completion
2017
Study completion
2018
First posted
Dec 16, 2016
Registry last updated
Aug 4, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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