title: Strabismus Measurements in Adults Before and After Pupil Dilation.
abstract: OBJECTIVE
  To determine the effect of dilating drops on strabismus measurements in adults.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Patients aged 18 and older with strabismus underwent a standard evaluation of ocular motility, stereopsis, and ocular alignment with alternate prism cover test by a certified orthoptist. After pupil dilation with 2.5% phenylephrine and 1% tropicamide, ocular alignment was remeasured in primary gaze at 6 meters, at 1/3 meter, and at 1/3 meter with a +3.00 by a second certified orthoptist, masked to the previous measurements. The primary outcome was the mean difference in the angle of horizontal and vertical deviations after dilation in prism diopters.
  
  
  RESULTS
  A total of 55 patients were enrolled with a variety of diagnoses. For horizontal measurements the mean change was 0.54 prism diopters at 6 meters (95% confidence interval [CI] -0.36 to 1.43, P = .24), 1.67 prism diopters at 1/3 meter (95% CI -0.19 to 3.54, P = .08), and -0.05 prism diopters at 1/3 meter with a +3.00 add (95% CI -1.65 to 1.56, P = .95). The mean change in vertical deviation was 0.18 prism diopters at 6 meters (95% CI -0.19 to 0.56, P = .34), 0.57 prism diopters at 1/3 meter (95% CI 0-1.15, P = .05), and 0.47 prism diopters at 1/3 meter with a +3.00 add (95% CI -0.23 to 1.17, P = .18).
  
  
  CONCLUSIONS
  Pupil dilation does not meaningfully affect vertical or horizontal strabismus measurements in adults. Mild variability at near in younger patients is eliminated with the use of a +3.00 add.
authors.affiliation: Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota; Ophthalmology Department, DaVita Medical Group, Albuquerque, New Mexico.
authors.forename: Sean S
authors.initials: SS
authors.lastname: Rivera
authors.affiliation: Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota; Department of Neurology, University of Minnesota, Minneapolis, Minnesota; Department of Neurosurgery, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Lee
authors.affiliation: Biostatistical Design and Analysis Center, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Scott
authors.initials: S
authors.lastname: Lunos
authors.affiliation: Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota; Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Jill S
authors.initials: JS
authors.lastname: Anderson
authors.affiliation: Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota; Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota. Electronic address: Bothun.Erick@mayo.edu.
authors.forename: Erick D
authors.initials: ED
authors.lastname: Bothun
mesh_terms: D000293:Adolescent; D000328:Adult; D005133:Eye Movements / Q000187:drug effects / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009184:Mydriatics / Q000008:administration & dosage*; D009883:Ophthalmic Solutions; D011446:Prospective Studies; D011680:Pupil / Q000187:drug effects*; D013285:Strabismus / Q000175:diagnosis* / Q000503:physiopathology; D055815:Young Adult
chemical_list: D009184:Mydriatics; D009883:Ophthalmic Solutions