title: [Clinical features and surgical treatment of A-pattern exotropia].
abstract: OBJECTIVE
  To investigate the clinical features of A-pattern exotropia and to evaluate the efficacy of surgical treatment for the correction of A-pattern exotropia (A-XT).
  
  
  METHODS
  Pre- and post-operative eye position, superior oblique muscle function, clinical features and binocular function were examined and analyzed in 32 patients with A-pattern exotropia.
  
  
  RESULTS
  Overaction of the superior oblique (SO) (31/32) and insufficiency of medial rectus muscle (20/32) were commonly seen in the group of patients. The tenectomy of the SO and the resection of the medial rectus muscle were effective in most of A-pattern exotropia. 87.5% (28/35) of A-pattern exotropia in our study were successfully corrected. Four cases got binocular function after surgery.
  
  
  CONCLUSIONS
  Based on the clinical features and the effects of surgical treatment, we conclude that the superior oblique muscle overaction and medial rectus muscle insufficiency are the primary factors in the etiology of A-pattern exotropia that is the most common form of A-V syndrome. Weakening the overaction of superior oblique muscle combined with the correction of exotropia is an effective way to correct A-pattern exotropia.
authors.affiliation: Zhongshan Ophthalmic Center, Sun-Yatsen University, Guangzhou 510060, China. ghm44@163.com
authors.forename: Guang-huan
authors.initials: GH
authors.lastname: Mai
authors.forename: Da-ming
authors.initials: DM
authors.lastname: Deng
authors.forename: Xiao-ming
authors.initials: XM
authors.lastname: Lin
authors.forename: Ying
authors.initials: Y
authors.lastname: Kang
authors.forename: Yan
authors.initials: Y
authors.lastname: Guo
authors.forename: Xiao
authors.initials: X
authors.lastname: Yang
authors.forename: Chun-xiu
authors.initials: CX
authors.lastname: Yuan
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005099:Exotropia / Q000145:classification / Q000503:physiopathology / Q000601:surgery*; D005133:Eye Movements / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009801:Oculomotor Muscles / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome