title: Importance of Accommodation and Eye Dominance for Measuring Objective Refractions.
abstract: OBJECTIVE
  To explore factors affecting the difference between objective refractive data measured under monocular closed-field viewing and binocular open-field viewing.
  
  
  METHODS
  Prospective observational case series.
  
  
  METHODS
  setting: Institutional.
  
  
  METHODS
  Twenty-nine healthy volunteers (58 eyes; mean age, 38.4 ± 10.0 years; range, 25-60 years).
  
  
  METHODS
  Objective monocular refractions (MR) measured with the Nidek Auto Ref/Keratometer ARK-730A; objective binocular refractions (BR) and objective accommodative amplitude (AA) measured with the Grand Seiko Auto Ref/Keratometer WAM-5500; ocular dominance measured using the hole-in-the-card test; presence and magnitude of far/near (30 cm) phoria evaluated by the cover test and alternating cover test using a prism bar.
  
  
  METHODS
  The difference between objective refractive data measured under monocular closed-field viewing and binocular open-field viewing.
  
  
  RESULTS
  The spherical equivalent (SE) of the BR was significantly (P < .001) more hyperopic by 0.51 ± 0.33 diopter (D) than the MR. The difference (BR minus MR) tended to decline with increasing age and decreasing AA (r = -0.231, P = .08; r = 0.223, P = .092, respectively). The correlation between age and difference in SE was significant in dominant eyes (r = -0.372, P = .047) but not in nondominant eyes (r = -0.102, P = .60). In nondominant eyes, the amount of near phoria was correlated significantly (r = 0.403, P = .03) with the difference in SE. The correlation was strong (r = 0.598, P = .01) in 17 subjects with more than 3 D of AA.
  
  
  CONCLUSIONS
  Binocular assessment of refraction is important for precise refractive therapy.
authors.affiliation: Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Yukari
authors.initials: Y
authors.lastname: Tsuneyoshi
authors.affiliation: Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan. Electronic address: fwic7788@mb.infoweb.ne.jp.
authors.forename: Kazuno
authors.initials: K
authors.lastname: Negishi
authors.affiliation: Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tsubota
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D000328:Adult; D023882:Dominance, Ocular; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology*; D013285:Strabismus / Q000175:diagnosis / Q000503:physiopathology*; D014787:Vision Tests; D015348:Vision, Binocular / Q000502:physiology*; D055815:Young Adult