title: Usefulness of the preoperative prism adaptation test in patients with intermittent exotropia.
abstract: OBJECTIVE
  To investigate whether the preoperative prism adaptation test is useful in patients with intermittent exotropia.
  
  
  METHODS
  Sixty-five consecutive patients with basic-type intermittent exotropia <40 prism diopters (PD) comprised the study population in this prospective study. Patients were divided into two groups based on the results of the prism adaptation test. Patients with a negative response comprised group 1 and patients with a positive response comprised group 2. Group 1 patients (n=26) underwent surgery according to the original angle, and group 2 patients (n=27) underwent surgery in accordance with the change in the angle of deviation with prisms.
  
  
  RESULTS
  Satisfactory motor alignment (+/- 5 PD of orthophoria) was achieved in 14 (53.8%) group 1 patients and 24 (88.8%) group 2 patients (P=.01). Mean residual deviation was 9.8 PD in group 1 and 4.5 PD in group 2 (P < or = .05).
  
  
  CONCLUSIONS
  The prism adaptation test may be helpful in achieving a favorable surgical outcome in intermittent exotropia.
authors.affiliation: Squint and Orthoptic Section, Guru Nanak Eye Centre, Maulana Azad Medical College, Delhi, India.
authors.forename: Subhash
authors.initials: S
authors.lastname: Dadeya
authors.lastname: Kamlesh
authors.forename: Sanjive
authors.initials: S
authors.lastname: Naniwal
mesh_terms: D000221:Adaptation, Ocular; D002648:Child; D002675:Child, Preschool; D005099:Exotropia / Q000175:diagnosis* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000473:pathology* / Q000601:surgery; D013508:Ophthalmologic Surgical Procedures / Q000379:methods; D009988:Orthoptics / Q000379:methods; D011446:Prospective Studies; D016896:Treatment Outcome; D014787:Vision Tests / Q000379:methods*; D015348:Vision, Binocular