Binasal occlusion for the non-invasive management of acute acquired comitant esotropia

Purpose To assess the clinical effectiveness of binasal occlusion (BNO) as a non-invasive treatment for acute acquired comitant esotropia (AACE) and to explore potential predictors of therapeutic response. Methods This retrospective case series included 32 AACE patients who underwent BNO therapy for at least 6 months. Changes in ocular deviation angles, diplopia resolution, and binocular function were assessed before and after treatment. Patients were categorized into cured (orthophoria), effective [≥10 prism diopter (PD) reduction], and ineffective groups. Univariate and multivariate analyses were conducted to identify predictors of therapeutic success. Results BNO significantly reduced ocular deviation. The median near deviation decreased from 25.00 PD (IQR 20.00–30.00) to 17.50 PD (IQR 5.50–33.75) ( P = 0.002), and the median distance deviation decreased from 30.00 PD (IQR 21.25–40.00) to 20.00 PD (IQR 5.25–35.00) ( P < 0.001). Diplopia resolved in 50% of patients ( P < 0.001), and fusion function improved significantly ( P = 0.019). Smaller initial deviations and shorter disease duration were associated with favorable outcomes in univariate analysis but did not emerge as independent predictors in multivariate analysis, suggesting a potential synergistic interaction. Conclusion BNO represents a promising, non-invasive intervention for AACE, particularly in cases with smaller deviations and early presentation. This case series provides preliminary evidence that BNO may reduce deviation and potentially lower surgical need. However, the absence of a control group precludes causal inference. Future randomized controlled trials with standardized outcomes are needed to confirm efficacy and define BNO's role in AACE management.