Clinical trial NCT02995174: Will Perceptual Learning Via Video Game Playing Improve Visual Acuity Stereopsis & Fixation Stability in Mild Amblyopes?
Official title: Will Perceptual Learning Via Video Game Playing Improve Visual Acuity, Stereopsis and Fixation Stability in Mild Amblyopes? Part 2 Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Amblyopia
Keywords: amblyopia
fixation stability
perceptual learning
Lead sponsor: The Hong Kong Polytechnic University
Sponsor class: OTHER
First posted: 2016-12-16
Enrollment: 23
Sex: ALL
Minimum age (years): 7
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NON_RANDOMIZED
Intervention model: SEQUENTIAL
Primary purpose: TREATMENT

Brief summary: 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.

Detailed description: 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.

Eligibility criteria: 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

Primary outcomes:
measure: 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
timeFrame: 6 weeks
Secondary outcomes:
measure: Change in best corrected visual acuity (in log MAR) in the amblyopic eye after 6 weeks dichoptic video game playing in mild amblyopes
timeFrame: 6 weeks
measure: Change in stereopsis (in arc sec) after 6 weeks dichoptic video game playing in mild amblyopes
timeFrame: 6 weeks
Other outcomes:
Locations:
city: Hong Kong
country: Hong Kong
facility: The Hong Kong Polytechnic University
Study officials:
affiliation: The Hong Kong Polytechnic University
name: Carly Lam, PhD
role: PRINCIPAL_INVESTIGATOR
References:
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