Efficacy of 3D Movie Viewing Versus Occlusion on Stereopsis and Visual Function in Children With Amblyopia: A Randomized Controlled Trial
Efficacy of 3D Movie Viewing Versus Occlusion on Stereopsis and Visual Function in Children With Amblyopia: A Randomized Controlled Trial
Amblyopia is a common childhood visual disorder that affects vision in one eye and can also impair depth perception (stereopsis). Standard treatment typically involves occlusion therapy (patching the stronger eye), which improves visual acuity but often does not fully restore binocular vision.
This study aims to evaluate whether watching 3D movies, combined with occlusion therapy, improves visual outcomes more than occlusion therapy alone in children with amblyopia. The immersive nature of 3D content may stimulate binocular vision and enhance treatment effectiveness.
In this randomized controlled trial, children aged 4 to 14 years with amblyopia will be assigned to one of two groups: one group will receive standard occlusion therapy, while the other will receive occlusion combined with weekly 3D movie sessions. After an initial phase, all participants will have access to 3D viewing sessions.
The study will assess improvements in depth perception, visual acuity, and eye alignment over time. The goal is to determine whether this combined approach provides additional benefits and could be used as a complementary therapy for amblyopia.
Amblyopia is the leading cause of monocular visual impairment in children, with a prevalence of approximately 2-3%. It is commonly associated with strabismus and/or anisometropia and is characterized by reduced visual acuity and deficits in binocular vision, particularly stereopsis. While conventional treatments such as refractive correction and occlusion therapy are effective in improving visual acuity, many patients retain residual deficits in stereopsis and binocular function.
Recent advances in amblyopia treatment have focused on binocular approaches, including perceptual learning, dichoptic training, and virtual reality-based interventions. These methods aim to stimulate binocular interaction and reduce suppression of the amblyopic eye. Among these approaches, 3D movie viewing represents a naturalistic and engaging stimulus that introduces large binocular disparities and may promote binocular integration in a child-friendly environment.
Preliminary evidence from a pilot study conducted by our group demonstrated that a single 3D movie session can produce significant and sustained improvements in stereopsis and visual acuity in children with a history of amblyopia. However, this study lacked a control group and involved only a single exposure session.
The present study is a prospective, randomized, controlled, single-center clinical trial designed to evaluate the efficacy of repeated 3D movie viewing sessions combined with occlusion therapy compared to occlusion therapy alone. Participants will be randomly assigned to either an experimental group (3D viewing plus occlusion) or a control group (occlusion alone). The intervention will consist of 3 to 6 weekly sessions of 3D movie viewing, each lasting approximately 90-120 minutes.
The study includes two phases: an initial comparative phase in which outcomes between groups are assessed after three sessions, and a second phase in which all participants are exposed to additional 3D sessions to evaluate cumulative effects. Assessments will be conducted at baseline (T0), after the first phase (T1), and after completion of all sessions (T2).
Primary outcome measures include stereopsis (measured in log arcseconds), visual acuity (logMAR), and ocular deviation (prism diopters). Secondary outcomes include sensory and motor characteristics (fusion, suppression, retinal correspondence), treatment adherence, and patient-reported satisfaction and quality of life.
Outcome assessors will be masked to group allocation to reduce bias. The study also aims to explore factors influencing treatment response, including age and type of amblyopia.
This trial seeks to determine whether 3D movie viewing can serve as an effective, engaging, and non-invasive adjunct to conventional amblyopia treatment, with potential implications for improving both visual function and patient adherence.
Inclusion Criteria:
Children aged 4 to 14 years Diagnosis of unilateral amblyopia (anisometropic, strabismic, or mixed) Interocular visual acuity difference ≥ 0.2 logMAR (equivalent to ≥ 2 Snellen lines) Ability to understand and follow age-appropriate instructions Written informed consent from parents or legal guardians Child assent obtained when applicable
Exclusion Criteria:
Previous treatment for amblyopia Ocular surgery within the last 6 months Strabismus with deviation greater than 10 prism diopters Presence of other ocular pathologies affecting vision (e.g., cataract, nystagmus, ptosis, corneal opacity, retinal disease, optic neuropathy) Neurological or cognitive impairment preventing compliance with study procedures Prior intensive exposure to 3D movies or virtual reality/3D video games that could act as a confounding factor Refusal of the child or family to participate
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