Association Between Visual Acuity and Binocular Fusion in Refractive Amblyopia

Purpose: To investigate alterations in perceptual fusion and motor fusion in children with refractive amblyopia before and after treatment, and analyze the relationship between fusion function and changes in best corrected visual acuity (BCVA). Methods: A study was undertaken of children with amblyopia aged 4 to 12 years who were treated at the outpatient department of Binzhou Medical College Affiliated Hospital from July 2024 to July 2025. The study comprised 38 children (38 eyes) with anisometropic amblyopia, 30 (30 eyes) with ametropic amblyopia, and 30 (30 eyes) with normal vision. All children with amblyopia underwent cycloplegic refraction, fusion function measurement, and comprehensive amblyopia treatment. Results: BCVA, perceptual fusion, positive fusion, and fusion range were significantly lower in children with refractive amblyopia compared to those with normal vision ( P < .001). Following 3 months of comprehensive amblyopia treatment, BCVA, positive fusion, and fusion range in children with amblyopia improved compared to pretreatment levels ( P < .001). The enhancement of perceptual fusion function in anisometropic amblyopia after treatment ( P = .001) was superior to that in ametropic amblyopia ( P = .125). A moderate positive correlation was observed between BCVA improvement and the enhancement of positive fusion function and fusion range ( r = 0.469, P = .003; r = 0.440, P = .006, respectively). Additionally, there was a weak positive correlation between the improvement in positive fusion function and BCVA ( r = 0.382, P < .05). Conclusions: Following treatment, positive fusion and fusion range improved significantly in refractive amblyopia. Perceptual fusion function was markedly enhanced in anisometropic amblyopia following treatment.