Outcomes of using Bangerter foils for the treatment of residual amblyopia following patching therapy

Purpose: To evaluate the effectiveness of additional treatment using Bangerter foil (BF) for children with residual amblyopia. Methods: Patients with residual amblyopia who were treated with BF between 2015 and 2020 were reviewed. Residual amblyopia was defined as no further improvement in vision following patching therapy for at least 6 months. BF that corresponds to the VA of the amblyopic eye was applied to the spectacle lens of the fellow eye. Patients were divided into two groups: group A, which included patients treated with BF alone, and group B, which included patients treated with BF and a head-mounted display. After at least 2 months of treatment, baseline and final VA and stereoacuity were compared. Results: Seventy-four patients with a mean age of 8.0 ± 1.6 years at the time of BF treatment were included. The mean duration of the BF treatment was 10.4 ± 5.6 months. After a mean follow-up period of 24.9 ± 11.9 months after BF treatment, the median (IQR) VA of the amblyopic eye changed from 0.20 (0.15–0.40) LogMAR to 0.10 (0.04–0.20) LogMAR (P = 0.001). The median (IQR) stereoacuity changed from 3.19 (2.53–3.75) log arcsec to 2.60 (2.15–3.48) log arcsec (P = 0.001). The number of patients improved vision by 0.2 LogMAR or more lines was 18 patients (30%) for group A and 3 patients (23%) for group B. The VA of the amblyopic eye before BF treatment was significantly associated with vision improvement. Conclusion: BF can be considered an alternative treatment plan to provide further benefit for children with residual amblyopia.