title: Botulinum toxin management of childhood intermittent exotropia.
abstract: OBJECTIVE
  Intermittent exotropia is a common form of childhood strabismus that has a late onset and presents a difficult and frustrating management dilemma. Surgical treatments have a high recurrence rate, and multiple surgeries often are required to achieve a desirable motor outcome. This study presents long-term observations on the use of botulinum toxin for the treatment of intermittent exotropia in children.
  
  
  METHODS
  This study is a nonrandomized, case-controlled study of consecutive pediatric patients who had intermittent exotropia.
  
  
  METHODS
  Thirty-two neurologically normal children ranging from 3 to 144 months in age were diagnosed with intermittent exotropia with a minimum distance deviation of 15 prism diopters (PD).
  
  
  METHODS
  Simultaneous bilateral injections of 2.5 units botulinum toxin type A were made into the lateral rectus muscles with the patient receiving nitrous oxide-ethrane inhalation anesthesia. Patients were observed for 12 to 44 months after the initial injection.
  
  
  METHODS
  A satisfactory outcome was considered to be stable binocular alignment of the eyes to an orthophoric range of +/-10 PD.
  
  
  RESULTS
  Bilateral lateral rectus muscle 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%). Overall, male patients required significantly fewer injections than did female patients. All patients between 24 and 56 months of age, irrespective of gender, required only a single bilateral injection to achieve a favorable motor outcome.
  
  
  CONCLUSIONS
  Botulinum toxin is at least as effective as surgical outcomes reported previously for the treatment of intermittent exotropia in children. This treatment method is particularly effective in children between 2 and 4.5 years of age irrespective of the initial strabismic angle and is not associated with any secondary abnormalities.
authors.affiliation: Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0146, USA.
authors.forename: R F
authors.initials: RF
authors.lastname: Spencer
authors.forename: M G
authors.initials: MG
authors.lastname: Tucker
authors.forename: R Y
authors.initials: RY
authors.lastname: Choi
authors.forename: K W
authors.initials: KW
authors.lastname: McNeer
mesh_terms: D000769:Anesthesia, Inhalation; D018726:Anti-Dyskinesia Agents / Q000627:therapeutic use*; D001905:Botulinum Toxins / Q000627:therapeutic use*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005099:Exotropia / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007223:Infant; D007267:Injections; D008297:Male; D009801:Oculomotor Muscles / Q000187:drug effects*; D016896:Treatment Outcome
chemical_list: D018726:Anti-Dyskinesia Agents; D001905:Botulinum Toxins