Effect of binasal occlusion in children with esotropia.

Background: Esotropia is a common pediatric ophthalmologic disorder that, if left untreated, can have a significant impact on the binocular visual function and appearance of the child. Binasal occlusion (BNO) is a non-surgical measure to alleviate the impact of esotropia. But there is no consistent theoretical basis for BNO and its therapeutic efficacy has been controversial. This study aimed to investigate the effect of BNO in the treatment of children with esotropia.

Methods: We performed a retrospective review of children with multiple types of esotropia who still had symptoms of obvious esotropia or the presence of visual diplopia after full refraction correction at the Affiliated Hospital of Yunnan University Hospital from October 2022 to September 2023. All the children were given BNO. Vision function and strabismic degree were examined before and after 3 months of BNO. The data were analyzed by Wilcoxon signed-rank test and Fisher's exact test.

Results: The mean value of the strabismus before BNO was significantly different from the mean value of the strabismus after BNO for 3 months, including near strabismus [25.22±18.25 vs. 9.63±11.92 prism diopters (PD); P<0.001], and distance strabismus (23.65±17.45 vs. 9.27±12.47 PD; P<0.001). Twenty-six cases were markedly corrected, 6 cases were effectively corrected, 9 cases were invalid. There was no significant difference in the efficacy of BNO between the various types of esotropia (F=8.333; P=0.15). Fifteen children had diplopia before, and 14 children reported the disappearance of diplopia after 3 months, with an effective rate of 93.33%.

Conclusions: BNO is an effective non-surgical treatment measure, which can effectively reduce the strabismus degree of many types of esotropia and improve the visual double-image situation, providing a good basis for the establishment of the subsequent visual function.