Efficacy Of Binocular Vision Therapy Versus Standard Occlusion Therapy in Improving Stereo-Acuity in Amblyopic Children

Abstract

Objective:  To improve the efficacy of BVT with standard occlusion therapy in improving stereoacuity and visual acuity in children with amblyopia.  

Study design: It was a Randomized Controlled Trial (RCT)

Place and Duration: The study was conducted at the Eye Clinic Dunyapur from March 2025 to June 2025.

Material and Methods: The study involved 54 amblyopic children aged between 5 to 12 years, clinically diagnosed with unilateral amblyopia (anisometropic, strabismic, or mixed type). All participants underwent baseline assessments, including distance and near visual acuity, and stereo-acuity measured using the Titmus Fly Stereo test. Participants were then divided into two equal groups (n = 30 each): Group A received binocular vision therapy, including vergence training, anti-suppression activities, and stereopsis exercises. Group B received standard occlusion therapy, involving patching of the non-amblyopic eye for 2–6 hours per day depending on the severity of amblyopia. Therapy adherence was monitored weekly by parental reports and compliance logs. Post-therapy evaluations were done at 8 weeks and again at 16 weeks, using the same stereo-acuity scale. Improvement in stereo-acuity was measured in seconds of arc, and data were analyzed using paired t-tests and Cohen’s d to determine statistical significance.

Results:  Hypermetropia reported significantly better outcomes compared to those with Astigmatic Myopia, as indicated by a Chi-Square value of 6.46 (p=0.04).In terms of clear vision at different distances, The Chi-Square values were 5.78 (p=0.12) and 6.58 (p=0.16) respectively. The ease of adapting to PALs showed no significant variation across refractive errors, as evidenced by Chi-Square values from 1.47 (p=0.83) for Myopia to 7.53 (p=0.28) for Astigmatic Myopia. Regarding the improvement in computer work experience with PALs, though the differences were not statistically significant between astigmatic myopia and hypermetropia. The Chi-Square values were 1.75 (p=0.42) for Myopia and 6.89 (p=0.14)

Conclusion: Binocular Vision Therapy demonstrated superior improvement in stereo-acuity among amblyopic children compared to standard occlusion therapy. BVT was more engaging for children, leading to better compliance and faster gains in binocular function. Although occlusion remains a foundational treatment, the addition of binocular activities significantly enhances depth perception recovery. Long-term integration of BVT into amblyopia treatment protocols is recommended.