title: A Valid Indication and the Effect of Bilateral Inferior Oblique Transposition on Recurrent or Consecutive Horizontal Deviation in Infantile Strabismus.
abstract: OBJECTIVE
  To evaluate the effects of bilateral inferior oblique transposition (BIOT) on horizontal deviation from primary position among patients with bilateral dissociated vertical deviation (DVD) associated with inferior oblique overaction (IOOA) in infantile strabismus.
  
  
  METHODS
  Retrospective chart review was conducted among 19 patients with infantile strabismus. All patients had DVD and IOOA with consecutive or recurrent horizontal deviation and underwent modified BIOT surgery. Patients were divided into three subgroups: patients who underwent BIOT (BIOT group, n = 9) alone, BIOT with medial rectus recession or lateral rectus resection simultaneously (ET BIOT group, n = 6), or BIOT with lateral rectus recession or medial rectus resection simultaneously (XT BIOT group, n = 4). Postoperative angle of horizontal deviation (prism diopter, PD) and corrected magnitude of horizontal deviation (PD) at final visit after surgery were analyzed in each group.
  
  
  RESULTS
  The mean age was 55.11 ± 21.05 months (range, 32 to 115). The mean follow-up period was 8.68 ± 2.87 months (range, 6 to 18). Preoperative horizontal deviation was 4.23 ± 5.99 PD (range, 0 to 16) in BIOT, -17.33 ± 6.76 PD (range, -30 to -10) in ET BIOT, and 17.50 ± 2.52 PD (range, 14 to 20) in XT BIOT. Esodeviation is represented by negative values. DVD and IOOA were reduced less than +1 in all patients. The corrected amount of horizontal deviation was 3.56 ± 5.18 PD (range, 0 to 16) in BIOT surgery alone and larger in XT BIOT (18.50 ± 3.41 PD) than in ET BIOT (12.33 ± 5.57 PD,p= 0.004).
  
  
  CONCLUSIONS
  Minimal exodeviation was corrected by BIOT alone. In addition, secondary eso- or exodeviation at great magnitudes should be corrected with proper horizontal muscle surgery along with BIOT.
authors.affiliation: Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea.
authors.forename: Suk-Gyu
authors.initials: SG
authors.lastname: Ha
authors.affiliation: Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea.
authors.forename: Gun-Hoo
authors.initials: GH
authors.lastname: Na
authors.affiliation: Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea.
authors.forename: Seung-Hyun
authors.initials: SH
authors.lastname: Kim
mesh_terms: D002675:Child, Preschool; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000503:physiopathology / Q000601:surgery*; D013508:Ophthalmologic Surgical Procedures / Q000379:methods*; D012189:Retrospective Studies; D013285:Strabismus / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D015348:Vision, Binocular / Q000502:physiology*
keywords: Infantile; Inferior oblique muscle; Strabismus; Surgery; Transposition