title: Comparison of monocular and binocular infrared pupillometers under mesopic lighting conditions.
abstract: OBJECTIVE
  To compare 3 infrared pupillometers under mesopic lighting conditions in refractive surgery candidates with moderate to high myopia.
  
  
  METHODS
  Johann Wolfgang Goethe-University, Department of Ophthalmology, Frankfurt/Main, Germany.
  
  
  METHODS
  In this prospective 1-day study, pupils of refractive surgery candidates with moderate to high myopia were measured with 3 infrared pupillometers: the monocular Colvard (monocular pupillometer A), the monocular PupilScan II (monocular pupillometer B), and the binocular Procyon P2000SA. Mesopic lighting conditions were consistent with the International Organization for Standardization for phakic intraocular lenses and manufacturer instructions as follows: 3 cd/m(2) (both monocular pupillometers), 0.4 lux (binocular pupillometer mesopic low setting), and user defined (binocular pupillometer user setting). Pupil diameters were measured twice per pupillometer by 2 independent examiners.
  
  
  RESULTS
  The study included 40 subjects (80 eyes). The mean pupil diameters were similar except with the mesopic low setting of the binocular pupillometer, which measured pupil diameter approximately 1.2 mm smaller. There was a high correlation between the 2 monocular pupillometers (0.83, P<.0001). The correlation between the monocular methods was stronger than that between the binocular user setting and either monocular method (monocular pupillometer A, r(2) = 0.665, P<.0001; monocular pupillometer B, r(2) = 0.594, P<.0001). No statistically significant difference was found between monocular pupillometer A, monocular pupillometer B, and the binocular pupillometer user setting.
  
  
  CONCLUSIONS
  Both monocular pupillometers and the binocular pupillometer user setting measured pupil diameter under mesopic conditions similarly in eyes with moderate to high myopia.
authors.affiliation: Department of Ophthalmology, Johann Wolfgang Goethe-University, Frankfurt/Main, Germany.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Scheffel
authors.forename: Christoph
authors.initials: C
authors.lastname: Kuehne
authors.forename: Thomas
authors.initials: T
authors.lastname: Kohnen
mesh_terms: D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D055255:Mesopic Vision / Q000502:physiology*; D009216:Myopia / Q000503:physiopathology*; D011446:Prospective Studies; D011680:Pupil / Q000502:physiology*; D015348:Vision, Binocular; D055815:Young Adult