title: Botulinum toxin injection in the patients with Duane syndrome type 1.
abstract: OBJECTIVE
  To evaluate the efficacy of botulinum toxin injection in the patients with type 1 Duane syndrome and identify the predictive factors for success.
  
  
  METHODS
  Sixteen patients with esotropic type 1 Duane syndrome without history of ocular surgery were selected for this interventional case series. The botulinum toxin was injected in the medial rectus of all patients. Visual acuity, dry refraction, cyclo-refraction, ocular motility, and amount of deviation were measured. Complete success, partial success, and failure were defined as residual deviation/face turn less than 8 prism diopters (PD)/5°, 8-20 PD/5-15°, and equal or greater than 20 PD/15°, respectively.
  
  
  RESULTS
  Sixteen cases (6 males) were included in our study. The mean esotropia was 26.27 ± 8.35 (12-40 PD) which was reduced significantly to 13.5 ± 12.39 PD during 6 months follow-up (p < 0.001). Face turn was improved significantly from a preoperative mean of 18.27° to: 0.094° at 1 week, 0.11° at 1 month, 3.31° at 3 months, and 7° at 6 months (p < 0.001). Complete success was seen in 6 patients (37.5%), partial success in 4 patients (25%), and failure in 6 patients (37.5%). There was a significant relation between the amount of forced duction testing (FDT) and the success rate (p: 0.019). No complication was seen during injections.
  
  
  CONCLUSIONS
  Botulinum toxin could be an alternative treatment in Duane syndrome with appropriate case selection. FDT could be a predictive factor for response to botulinum toxin.
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Ameri
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Farzad
authors.initials: F
authors.lastname: Farzbod
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Bazvand
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Arash
authors.initials: A
authors.lastname: Mirmohammadsadeghi
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Akbari
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Faramarz
authors.initials: F
authors.lastname: Anvari
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Simindokht
authors.initials: S
authors.lastname: Hosseini
keywords: Botulinum toxin; Duane syndrome; Esotropia