title: Monocular versus binocular pupillometry.
abstract: OBJECTIVE
  To quantify differences between monocular and binocular pupil size measurement under scotopic and mesopic conditions.
  
  
  METHODS
  Department of Ophthalmology, Johannes Gutenberg-University, and Department of Medical Biometry, Epidemiology and Informatics, University of Mainz, Mainz, Germany.
  
  
  METHODS
  Computerized dynamic pupillometry (P2000 SA, Procyon Instruments Ltd.) was used at 3 illumination levels: scotopic at 0.03 lux, mesopic low at 0.82 lux, and mesopic high at 6.4 lux. One hundred forty eyes of 70 healthy volunteers without ocular pathology were examined. The subjects were divided into 2 groups. In the first group, the pupil diameter was measured binocularly first. In the second group, monocular measurement was performed first. For statistical analysis, data description was based on medians and quartiles of the respective pupil diameter measurements. Intraindividual significance was based on sign tests, and interindividual comparison were based on 2-sample Wilcoxon tests.
  
  
  RESULTS
  In all eyes, statistically significant differences were found in pupil size, with higher values for the monocular measurement under low and high mesopic conditions (P=.000). For scotopic conditions, a trend toward higher values in monocular measurement was observed that approached statistical significance.
  
  
  CONCLUSIONS
  Results indicate that binocular measurement may imitate the patient's life conditions more realistically. Therefore, in eyes with a large pupil diameter with the risk for postoperative scotopic phenomena, binocular measurement should be considered before refractive surgery.
authors.affiliation: Department of Ophthalmology, Johannes Gutenberg-University Langenbeckstrasse, Mainz, Germany. kurz@augen.klinik.uni-mainz.de
authors.forename: Sabine
authors.initials: S
authors.lastname: Kurz
authors.forename: Frank
authors.initials: F
authors.lastname: Krummenauer
authors.forename: Norbert
authors.initials: N
authors.lastname: Pfeiffer
authors.forename: H Burkhard
authors.initials: HB
authors.lastname: Dick
mesh_terms: D000293:Adolescent; D000328:Adult; D003623:Dark Adaptation / Q000502:physiology; D003941:Diagnostic Techniques, Ophthalmological; D006801:Humans; D011680:Pupil / Q000502:physiology*; D015348:Vision, Binocular / Q000502:physiology*; D015349:Vision, Monocular / Q000502:physiology*