BOTULINUM TOXIN MANAGEMENT OF ESSENTIAL INFANTILE ESOTROPIA IN CHILDREN

Background: Infantile esotropia has an onset during early infancy when visual cortical connections are established for binocular fusion and stereopsis. The goal of early treatment is to achieve normal binocular alignment and a favorable sensory outcome. Objective: To determine th e long-term effects of the use of botulinum toxin for the management o f infantile esotropia in children. Patients: Seventy-six neurologicall y normal children ranging from 4 to 48 months of age were entered cons ecutively into the study after being given the initial diagnosis of in fantile esotropia with a mean strabismic angle of 33 prism diopters. I nterventions: Simultaneous bilateral injections of 2.5 U of botulinum toxin type A were made into the medial rectus muscles under nitrous ox ide and ethrane anesthesia. Patients were followed up for 12 to 95 mon ths after the last injection. Forty patients required 1 bilateral inje ction and 36 patients required multiple bilateral injections to achiev e a favorable motor outcome. Results: Bilateral medial rectus muscle i njections of botulinum toxin were effective in reducing the mean prein jection deviation of 33 PD to an average esotropic angle of 2 PD. Bino cular alignment (+/-10 PD) was achieved in 68 patients (89%). Boys req uired significantly fewer injections than did girls. The secondary inc idence of overacting inferior oblique muscles was significantly greate r in boys, while girls had a significantly greater incidence of late-o nset refractive errors. Conclusion: Botulinum toxin is an effective tr eatment modality for the management of infantile esotropia in infants and children, producing binocular alignment of the visual axes.