BOTULINUM TOXIN MANAGEMENT OF CHILDHOOD INTERMITTENT EXOTROPIA

Objective: intermittent exotropia is a common form of childhood strabi smus that has a late onset and presents a difficult and frustrating ma nagement dilemma, Surgical treatments have a high recurrence rate, and multiple surgeries often are required to achieve a desirable motor ou tcome. This study presents long-term observations on the use of botuli num toxin for the treatment of intermittent exotropia in children. Des ign: This study is a nonrandomized, case-controlled study of consecuti ve pediatric patients who had intermittent exotropia. Participants: Th irty-two neurologically normal children ranging from 3 to 144 months i n age were diagnosed with intermittent exotropia with a minimum distan ce deviation of 15 prism diopters (PD). Intervention: Simultaneous bil ateral injections of 2.5 units botulinum toxin 'type A were made into the lateral rectus muscles with the patient receiving nitrous oxide-et hrane inhalation anesthesia. Patients were observed for 12 to 44 month s after the initial injection. Main Outcome Measures: A satisfactory o utcome was considered to be stable binocular alignment of the eyes to an orthophoric range of +/-10 PD. Results: Bilateral lateral rectus mu scle injections of botulinum toxin were effective in reducing the mean preinjection deviation of -29 PD to an average exotropic angle of -6 PD. Stable orthophoria (+/-10 PD) was achieved in 22 patients (69%), O verall, male patients required significantly fewer injections than did female patients. All patients between 24 and 56 months of age, irresp ective of gender, required only a single bilateral injection to achiev e a favorable motor outcome. Conclusions: Botulinum toxin is at least as effective as surgical outcomes reported previously for the treatmen t of intermittent exotropia in children. This treatment method is part icularly effective in children between 2 and 4.5 years of age irrespec tive of the initial strabismic angle and is not associated with any se condary abnormalities.