The aim of this study was to evaluate the effectiveness of botulinum toxin type A (BTA) comparing to strabismus surgery in the treatment of children concomitant strabismus.

Consecutive patients with concomitant strabismus (142 cases) in Beijing Tongren Eye Center of Beijing Tongren Hospital from April 2018 to August 2019 were investigated. Among of them, including 74 male cases and 68 female cases with the average age (7.2±2.6) years-old. According to the choice of family members, patients were divided into injection group (BTA injection) and surgery group (strabismus surgery) . The esotropia deviation, binocular vision function and complications before and after treatment for 6 months and the alignment rate after treatment for 6 months. The esotropia deviation and the quantitative part of the binocular vision before and after treatment were expressed by mean±standard deviation. The paired t-test and independent sample t-test were used to compare within groups. The qualitative part of the binocular vision, alignment rate and complications were described by frequency and percentage, chi-square test was used to compare beteween groups.

After treatment for 6 months, the alignment rate of the injection group and the surgery group was respectivley 58.2% and 69.3% with non-significant difference between groups (χ²=1.90, P>0.05). The absolute values of strabismus before and after injection for6 months were (35.23±6.69)△ and (12.35±10.16)△; (35.40±8.74)△ and (9.16±9.43)△ in the injection group and surgery group, respectivley. There were no significant difference in the degree of strabismus between two groups before and after treatment for 6 months (t=-0.13, 1.92; P>0.05). At the 6 months follow-up after treatment, 25 cases accounting for 39.1% and 38 cases accounting for 50.7% of the subjects in the injection and surgery group had normal synoptophore level-Ⅰ function (simultaneous vision); 43 cases accounting for 67.2% and 70 cases accounting for 93.3% had level-Ⅱ function (fusion function); 26 cases accounting for 40.6% and 37 cases accounting for 49.3% had level-Ⅲ function (far stereopsis); 27 cases accounting for 42.2% and 38 cases accounting for 50.7% had normal near stereopsis, which were increased compared with that before treatment. Only the proportion of subjects with level-Ⅱ fusion function in the surgery group was better than that in the injection group after treatment for 6 months with significant difference between groups (χ²=15.52, P<0.05). There were not statistically different in level-Ⅰand level-Ⅲ fusion function(χ²=1.88, 1.06, 0.99; P>0.05). All patients in injection group complained of diplopia. There were 16 cases with complications in the injection group included ptosis, diplopia and subconjunctival hemorrhage, which disappeared at 1 to 3 months of follow-up.

For children with deviation of moderate to low degree (15△~50△), botulinum toxin type A was as effective as surgery in the treatment of children concomitant strabismus after treatment for 6 months, which is a safe and effective treatment.