title: Measurement of pupil center shift in refractive surgery candidates with caucasian eyes using infrared pupillometry.
abstract: OBJECTIVE
  To evaluate the effectiveness of the pupil center shift with changes in the state of pupil size and with other ocular variables.
  
  
  METHODS
  Dynamic pupillometry with the Topolyzer Vario (Alcon Laboratories, Inc., Fort Worth, TX) was performed in 248 eyes of 124 patients scheduled for corneal laser refractive surgery. High-resolution images were obtained using the infrared-sensitive camera (incorporated in the videokeratoscope) under mesopic and photopic conditions. Measurements of pupil diameters, distance between the pupil center and keratoscopic axis, and spatial shift of the pupil center were obtained after analysis.
  
  
  RESULTS
  The mean distance between the pupil center and the corneal vertex in mesopic and photopic conditions of illumination in myopic eyes was 0.27 ± 0.14 (range: 0.02 to 0.70 mm) and 0.24 ± 0.12 mm (range: 0.06 to 0.65 mm), respectively, whereas it was 0.36 ± 0.15 (range: 0.03 to 0.70 mm) and 0.31 ± 0.16 mm (range: 0.03 to 0.77 mm) in hyperopic eyes, respectively. The mean spatial pupil center shift was significant: 0.11 ± 0.07 mm (range: 0.02 to 0.57 mm) in myopic eyes and 0.12 ± 0.09 mm (range: 0.02 to 0.47 mm) in hyperopic eyes. The pupil center shifted consistently temporally as the pupil dilated. The pupil center shift was not significantly related to sex, age, eye (right or left), or refractive error.
  
  
  CONCLUSIONS
  The mean distance between the pupil center and the corneal vertex is greater in hyperopic eyes than in myopic eyes, whereas the spatial shift of this pupil center has a temporal direction as the pupil dilates and is constantly small in all groups. However, pupil center shift can be important in a few patients.
authors.forename: Imene Salah
authors.initials: IS
authors.lastname: Mabed
authors.forename: Alain
authors.initials: A
authors.lastname: Saad
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Guilbert
authors.forename: Damien
authors.initials: D
authors.lastname: Gatinel
mesh_terms: D000328:Adult; D000368:Aged; D055253:Color Vision / Q000502:physiology; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D005260:Female; D006801:Humans; D007498:Iris / Q000473:pathology*; D008297:Male; D055255:Mesopic Vision / Q000502:physiology; D008875:Middle Aged; D015878:Mydriasis / Q000503:physiopathology; D011680:Pupil / Q000502:physiology*; D054140:Refractive Surgical Procedures; D044465:White People; D055815:Young Adult