Study protocol for a randomized controlled trial using VISIONARY, a dichoptic Gabor patch video game, to improve visual function in children with amblyopia

Abstract

Abstract Background: Conventional treatment for amblyopia, involving occlusion and penalization of the dominant eye, does not always lead to effective outcomes and is associated with a high risk of recurrence and non-compliance. In this article, we present a protocol for a randomized controlled trial to evaluate the safety and clinical efficacy of Visionary, a novel computer-based therapy that uses dichoptic Gabor patches and band-filtered noise to treat amblyopia in the patient’s home. Methods: Our aim is to recruit a total of 120 children with amblyopia, aged 4–12 years, from the Paediatric Ophthalmology Unit at the Merida Hospital in Badajoz (Spain). The children will be divided into two groups according to whether or not they have previously undergone treatment involving occlusion or penalization of the dominant eye: 60 participants with no history of occlusion or penalization treatment will be assigned to Group A (GA), while Group B (GB) will consist of 60 participants who have previously received treatment with an occlusion dose > 32 weeks in mild or moderate amblyopia or > 48 weeks in severe amblyopia. In GA, the participants will be randomly assigned to either an experimental subgroup (GA-E) or a control subgroup (GA-C). Members of the GA-E group will be prescribed home therapy using computer-based exercises (Visionary); members of the GA-C group will be prescribed occlusion according to Pediatric Eye Disease Investigation Group (PEDIG) protocols. In GB, all participants will receive occlusion according to PEDIG protocols, and all will be prescribed home therapy using Visionary. In the experimental subgroup (GB-E), the computer will adjust the training spatial frequency of the Gabor patch, taking into account the user’s visual acuity (VA); while in the control subgroup (GB-C), the spatial frequency will remain low, irrespective of the patient’s VA. Visual function assessments will be carried out prior to the intervention and every three weeks thereafter; changes in best corrected visual acuity (BCVA) at distance will be the primary outcome measure under consideration. Stereoacuity and patient compliance will also be assessed. Discussion: The Visionary system based on dichoptic Gabor patches was originally conceived as a serious game to provide vision training to amblyopic children by combining the concepts of perceptual learning, dichoptic training, and gamification in the home environment. We hope that this novel approach may lead to greater improvements in vision performance in amblyopic children, as a substitute for occlusion treatment in novel amblyopia or as an adjunct treatment option in persistent amblyopia. Trial registration: This protocol was registered with ClinicalTrials.gov (NCT06150391) on 29th of November 2023.