Augmented Reality-Based Binocular Therapy for Visual Rehabilitation in Adults With Amblyopia

Condition(s) studied

Investigational drug(s) / intervention(s)

Active Augmented Reality-Based Binocular Therapy: Active augmented reality-based binocular therapy will be delivered using a Meta Quest 3 mixed-reality headset operating in passthrough mode. Participants will complete 40-minute sessions four times per week for 10 weeks, initially learning to use the system in a clinical setting and subsequently continuing the training at home. The real-world scene presented to the amblyopic eye will remain close to natural viewing, while the contrast presented to the dominant eye will be selectively reduced. This controlled contrast reduction gives the amblyopic eye a relative visual advantage, encouraging its more active contribution during binocular viewing and promoting binocular integration. The degree of contrast modulation will be adjusted according to visual performance over the course of treatment.

Placebo Augmented Reality-Based Visual Training: Placebo augmented reality-based visual training will be delivered using the same Meta Quest 3 mixed-reality headset operating in passthrough mode, with the same session duration, training schedule, and home-based setting as the active intervention. Participants will view and interact with their real-world surroundings while carrying out similar visual activities. Unlike the active intervention, the contrast presented to the dominant eye will not be selectively reduced. The visual information presented to both eyes will remain equivalent or will be only minimally and symmetrically modified, without providing active binocular rebalancing or a therapeutic visual advantage to the amblyopic eye.

Study summary

The goal of this clinical trial is to evaluate a home-based augmented reality-based binocular therapy designed to improve visual function in adults aged 18 to 40 years with unilateral anisometropic amblyopia, commonly called "lazy eye." The therapy is designed to be used during everyday activities, allowing visual training to be integrated into the participant's normal home routine.

The main questions this study aims to answer are:

* Does the Ambly4Home augmented reality-based binocular therapy improve visual acuity in the amblyopic eye and binocular vision compared with placebo visual training?
* Are any improvements in visual function maintained 6 months after the treatment has ended?
* Is the treatment associated with changes in other measures of visual function, retinal structure and function, and visual brain function?

Participants will be randomly assigned to receive either active binocular therapy or placebo visual training. Both groups will use the same mixed-reality device, follow the same training schedule, and carry out similar daily activities while viewing their real-world surroundings through the device. In the active treatment, the image presented to the amblyopic eye will remain close to the natural scene, while the contrast of the image presented to the stronger eye will be selectively lowered. This gives the amblyopic eye a relative visual advantage, helping to rebalance the input from the two eyes and encouraging them to work together.

In the placebo group, participants will use the same device under the same conditions, but without the selective contrast reduction used in the active treatment. This comparison will allow researchers to isolate the specific effect of selectively lowering the contrast seen by the stronger eye.

Participants will:

* Complete 40-minute training sessions four times per week for 10 weeks.
* Learn how to use the system in a clinical setting before continuing the training at home.
* Attend assessment visits before treatment, after 10 weeks of treatment, and 6 months after treatment has ended.
* Complete tests of visual acuity, depth perception, suppression between the eyes, and contrast sensitivity, as well as retinal imaging, retinal function testing, and brain imaging.

Eligibility

Primary outcome measure(s)

• Change From Baseline in Best-Corrected Visual Acuity of the Amblyopic Eye at Week 10 — Baseline and Week 10
  Best-corrected visual acuity of the amblyopic eye will be assessed monocularly using a standardized ETDRS chart and recorded as the number of letters correctly identified. Higher ETDRS letter scores indicate better visual acuity. Change from baseline will be calculated as the Week 10 letter score minus the baseline letter score. A positive change indicates an improvement in visual acuity.

Trial sites (2)

More Polytechnic Institute of Porto trials in Portugal

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