A Comparative Study of the Efficacy of AR Based Amblyopia Training Therapy and Occlusion Therapy in Older Children and Adults With Amblyopia

Amblyopia is the most prevalent developmental visual disorder in children, characterized by a reduction in best-corrected visual acuity in one or both eyes that cannot be attributed to optical anomalies or organic ocular pathologies. Epidemiological investigations have demonstrated that the prevalence of amblyopia among children ranges from 3% to 6%, rendering it one of the leading causes of unilateral visual impairment in pediatric populations. Beyond reduced visual acuity, amblyopia may also induce deficits in stereopsis, oculomotor coordination, and cognitive function, which substantially compromise patients' daily activities. Current mainstream clinical interventions for amblyopia primarily include refractive correction, occlusion therapy, penalization therapy, and visual function training.

Given the existence of a critical period for the development of the visual cortex in children, the treatment of amblyopia is constrained by a distinct therapeutic time window. Earlier intervention yields a higher probability of visual acuity recovery. Conversely, patients treated beyond the critical period of visual development generally exhibit a poor response to conventional therapies. Accordingly, amblyopia in older children and adults remains a major clinical challenge. With advancing research on the binocular pathogenesis of amblyopia-such as binocular imbalance induced by binocular contrast gain control and impairment of the parvocellular visual pathway originating from the lateral geniculate nucleus (LGN)-novel therapeutic strategies for amblyopia have been continuously developed.

Visual perceptual learning, which involves repeated training on near-threshold visual tasks to strengthen relevant neural pathways and elicit long-term improvements in visual function, has achieved favorable clinical outcomes in amblyopic patients. Since this approach can facilitate cortical plasticity, adult amblyopes who fail to respond to conventional treatments also show marked therapeutic responses. In recent years, dichoptic training, which delivers distinct visual stimuli to each eye simultaneously to promote binocular coordination and rehabilitate the parvocellular pathway, has exhibited promising efficacy in ameliorating monocular and binocular visual functions and shortening treatment duration in amblyopic patients.

Augmented Reality (AR) has attracted considerable attention due to its immersive interactive properties. By superimposing virtual visual stimuli onto the real-world environment, AR provides an innovative modality for amblyopia management. Compared with traditional therapies, AR systems enable real-time modulation of stimulus parameters (e.g., spatial frequency, contrast, and binocular balance), thereby supporting personalized and precise treatment. Preliminary studies have verified that AR-based training can significantly enhance contrast sensitivity and stereoscopic vision in adult amblyopes. Additionally, the gamified design of visual tasks remarkably improves patient adherence to treatment.

Nevertheless, existing studies on AR-based amblyopia training are mostly confined to laboratory settings or short-term interventions. Large-scale real-world evidence is still lacking to validate its long-term safety and general applicability. Furthermore, the assessment of visual function improvements after treatment mainly relies on visual acuity measurements, which represents a limited evaluation framework; comprehensive and systematic assessment systems remain underdeveloped.

In addition, amblyopia in individuals over 12 years of age (older children and adults) constitutes a difficult-to-treat cohort in clinical practice. These patients present low cortical plasticity and poor responses to occlusion therapy. Although dichoptic training is capable of inducing cortical plasticity, systematic real-world studies on this intervention are still insufficient. Therefore, the present study conducted in routine clinical settings targeting this specific population not only possesses important clinical implications, but also provides theoretical and practical evidence for the establishment of novel therapeutic regimens for amblyopia.

Inclusion criteria

• Individuals aged 12 to 55 years (12 ≤ age ≤ 55 years). Written informed consent shall be obtained from participants aged 18 years and above, or their legal guardians for those aged 12 to 17 years.
• Unilateral amblyopia with the following criteria: the best-corrected visual acuity (BCVA) of the dominant eye ≥ 0.8, and an interocular BCVA difference of two or more lines. Participants shall have confirmed amblyopia with relevant risk factors and no organic ocular diseases.
• For Individuals with refractive errors: the spherical equivalent (SE) measured via cycloplegic autorefraction or phoropter refraction ≤ -6.00 D. All participants shall have received optical refractive correction for more than 3 months, with stable visual acuity (acuity change < 1 line) within the latest 2 months.
• Individuals with orthotropic eye position, including patients with strabismic amblyopia after strabismus correction. The distance manifest deviation measured at 6 m using the prism and alternate cover test shall be within 5 prism diopters (△).
• Individuals who are willing to enroll in this study and are able to complete the entire trial protocol.

Exclusion criteria

• Participants with other organic ocular disorders, including media opacities, nystagmus, eccentric fixation, acute inflammatory conditions such as keratitis, optic neuropathy, including glaucoma, retinal lesions, and cortical visual impairment.
• Individuals diagnosed with tumors, cardiac diseases, hypertension, or epilepsy.
• Individuals with implanted electronic devices such as cardiac pacemakers.
• Individuals presenting with severe ocular inflammation, photophobia, or lacrimation in either eye.
• Individuals with a history of ocular surgery that affects visual function, excluding congenital cataract extraction combined with intraocular lens implantation, strabismus correction and blepharoptosis repair.
• Individuals with severe mental disorders or poor treatment adherence.
• Individuals currently using or planning to use medications that may affect visual function (mydriatic eye drops for refraction examination such as atropine are excluded).
• Individuals with diplopia or inability to achieve binocular fusion during augmented reality-based amblyopia training.
• Individuals who received any amblyopia treatments except spectacle lenses within 2 weeks prior to screening.
• Individuals who enrolled in other clinical drug trials within 3 months or other medical device trials within 1 month before recruitment.
• Individuals who are unable to attend regular ophthalmological examinations.
• Individuals deemed ineligible by the investigators.