title: Botulinum toxin treatment in patients up to 3 years of age who have esotropic Duane retraction syndrome.
abstract: OBJECTIVE
  To report the results of botulinum toxin (BOTOX®, Allergan) type A (BTA) bilateral injection in the treatment of Duane retraction syndrome (DRS) type 1 in patients aged up to 3 years.
  
  
  METHODS
  We studied the results of BTA bilateral injection in eight consecutive patients with DRS type 1 and esotropia in primary gaze. Average follow-up was 74 ± 71 months. The main variables analyzed were horizontal and vertical deviation and face turn. Patients were anesthetized with nitrous oxide (N2O). A mean dosage of 5.6 ± 1.8 IU (range 2.5-7.5 IU) of botulinum toxin diluted in 0.9% saline solution was injected under electromyography control in each medial rectus muscle.
  
  
  RESULTS
  Seven patients had one affected eye and one patient had bilateral involvement. The mean preoperative esotropia was 32 ± 10 prism diopters (PD). Three patients (37.5%) had also a vertical deviation. All patients had face turn ranging between 15° and 45° before BTA injection. In the last follow-up, 4 patients were orthotropic (50%), 1 (12.5%) had 3 PD exotropia and 3 (37.5%) had esotropia averaging 25 PD mean. The 3 esotropic patients needed surgical correction. Vertical strabismus improved in 3 patients achieving complete resolution in one of these patients. Two patients, without vertical strabismus before the BTA injection, developed a 5-PD vertical deviation, one of them required surgery. Face turn improved in all patients.
  
  
  CONCLUSIONS
  Botulinum toxin injection is an alternative treatment for patients with DRS type 1 presents esotropia and face turn in children up to 3 years of age.
authors.affiliation: Hospital Clínico San Carlos, Complutense University of Madrid, Spain. jesusfraile@yahoo.com
authors.forename: Jesús Fraile
authors.initials: JF
authors.lastname: Maya
authors.forename: Rosario Gómez
authors.initials: RG
authors.lastname: de Liaño
authors.forename: María Rocio García
authors.initials: MR
authors.lastname: Catalán
authors.forename: Omar
authors.initials: O
authors.lastname: Rayward
mesh_terms: D019274:Botulinum Toxins, Type A / Q000008:administration & dosage*; D002675:Child, Preschool; D004370:Duane Retraction Syndrome / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D004576:Electromyography; D004948:Esotropia / Q000150:complications* / Q000188:drug therapy / Q000503:physiopathology; D005133:Eye Movements / Q000187:drug effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007273:Injections, Intramuscular; D008297:Male; D009465:Neuromuscular Agents / Q000008:administration & dosage; D009801:Oculomotor Muscles / Q000187:drug effects / Q000503:physiopathology*; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A