Conventional surgery versus botulinum toxin injection for the management of esotropia in children with Down syndrome

Purpose To compare the success rates of strabismus surgery and botulinum toxin injection (BTX) in treating esotropia in patients with Down syndrome (DS). Methods This multicenter retrospective cohort study included all consecutive patients having DS with esotropia between 2014 and 2021 at King Abdullah Specialist Children Hospital, King Abdullah International Medical Research Center, and King Khaled Eye Specialist Hospital, Saudi Arabia. We divided the patients into two groups according to interventions. Success was defined as angle of deviation of <10Δ at final visit. Results A total of 53 patients were included: 23 in the surgery group and 30 in the BTX group. There were no significant differences between groups with regard to age, sex, diagnosis, spherical equivalent, and preoperative deviation angle. Before the intervention, the median angle of deviation was 30.0Δ (IQR, 30Δ-45Δ) in the surgery group and 37.5Δ (IQR, 28.8Δ-50.0Δ) in the BTX group (P = 0.802). Postoperatively, the median (IQR) deviation angle was 0.0Δ (0.0Δ-16.0Δ) in the surgery group and 22.5Δ (6.75Δ-30.0Δ) in the BTX group (P = 0.006). The success rate in the surgery and BTX groups was 65% and 30%, respectively (P = 0.011). Two patients developed dissociated vertical deviation in the surgery group. One patient presented consecutive exotropia and one inferior oblique overaction in the BTX group. Conclusions In this study, conventional surgery showed a higher success rate than BTX in the management of esotropia. To compare the success rates of strabismus surgery and botulinum toxin injection (BTX) in treating esotropia in patients with Down syndrome (DS). This multicenter retrospective cohort study included all consecutive patients having DS with esotropia between 2014 and 2021 at King Abdullah Specialist Children Hospital, King Abdullah International Medical Research Center, and King Khaled Eye Specialist Hospital, Saudi Arabia. We divided the patients into two groups according to interventions. Success was defined as angle of deviation of <10Δ at final visit. A total of 53 patients were included: 23 in the surgery group and 30 in the BTX group. There were no significant differences between groups with regard to age, sex, diagnosis, spherical equivalent, and preoperative deviation angle. Before the intervention, the median angle of deviation was 30.0Δ (IQR, 30Δ-45Δ) in the surgery group and 37.5Δ (IQR, 28.8Δ-50.0Δ) in the BTX group (P = 0.802). Postoperatively, the median (IQR) deviation angle was 0.0Δ (0.0Δ-16.0Δ) in the surgery group and 22.5Δ (6.75Δ-30.0Δ) in the BTX group (P = 0.006). The success rate in the surgery and BTX groups was 65% and 30%, respectively (P = 0.011). Two patients developed dissociated vertical deviation in the surgery group. One patient presented consecutive exotropia and one inferior oblique overaction in the BTX group. In this study, conventional surgery showed a higher success rate than BTX in the management of esotropia.