title: The impact of prism adaptation test on surgical outcomes in patients with primary exotropia.
abstract: BACKGROUND
  We aimed to determine the impact of the preoperative prism adaptation test (PAT) on surgical outcomes in patients with primary exotropia.
  
  
  METHODS
  Thirty-eight consecutive patients with primary exotropia were enrolled. Pre-operative PAT was performed in 18 randomly selected patients (Group 1). Surgery was based on the angle of deviation at distance measured after PAT. The remaining 20 patients in whom PAT was not performed comprised Group 2. Surgery was based on the angle of deviation at distance in these patients. Surgical success was defined as ocular alignment within eight prism dioptres (PD) of orthophoria.
  
  
  RESULTS
  Satisfactory motor alignment (± 8 PD) was achieved in 16 Group 1 patients (88.9 per cent) and 16 Group 2 patients (80 per cent) one year after surgery (p = 0.6; chi-square test). There were no statistically significant differences in demographic parameters, pre-operative and post-operative angle of deviation between the two groups (p > 0.05; Mann-Whitney U and chi-square tests). Nine patients in Group 1 (50 per cent) and two patients in Group 2 (10 per cent) had increased binocular vision one year post-operatively. A statistically significant difference was determined in terms of change in binocular single vision between the two groups (p = 0.01; chi-square test).
  
  
  CONCLUSIONS
  Although the prism adaptation test did not lead to a significant increment in motor success, it may be helpful in achieving a more favourable functional surgical outcome in patients with primary exotropia.
authors.affiliation: Ophthalmology Department, School of Medicine, Ege University, Izmir, Turkey.
authors.forename: Ayse
authors.initials: A
authors.lastname: Kiyak Yilmaz
authors.affiliation: Ophthalmology Department, School of Medicine, Ege University, Izmir, Turkey.
authors.forename: Suheyla
authors.initials: S
authors.lastname: Kose
authors.affiliation: Ophthalmology Department, School of Medicine, Ege University, Izmir, Turkey. drsuzan2003@yahoo.com.
authors.forename: Suzan
authors.initials: S
authors.lastname: Guven Yilmaz
authors.affiliation: Ophthalmology Department, School of Medicine, Ege University, Izmir, Turkey.
authors.forename: Onder
authors.initials: O
authors.lastname: Uretmen
mesh_terms: D000221:Adaptation, Ocular / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005099:Exotropia / Q000503:physiopathology / Q000628:therapy*; D005139:Eyeglasses; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009801:Oculomotor Muscles / Q000503:physiopathology / Q000601:surgery*; D013508:Ophthalmologic Surgical Procedures / Q000379:methods*; D011446:Prospective Studies; D016896:Treatment Outcome; D015348:Vision, Binocular; D055815:Young Adult
keywords: exotropia; prism adaptation test; surgery