Comparison of three different technologies for pupil diameter measurement

  • Sabine Schmitz
  • Frank Krummenauer
  • Sebastian Henn
  • H. Burkhard Dick
Clinical Investigation

Abstract

Background

The pupil diameter plays an important role in the occurrence of photopic phenomena after refractive surgery. Standardized estimation can be performed using a lens system with a built-in millimeter scale (Colvard, Oasis Medical, California). A new computerized technique allows dynamic and binocular measurement of the pupil diameter by use of infrared light (P2000SA, Procyon Instruments, London, UK). An additional approach is a wavefront aberrometer based on the Hartmann-Shack principle (WASCA; Asclepion-Meditec-Zeiss, Jena, Germany). These strategies were compared.

Design

Non-randomized comparative trial.

Participants and methods

The pupil diameter of 56 eyes of 28 probands (18 female, mean age 23 years) was measured under scotopic conditions by three independent examiners with each measurement device. The measurement devices were compared intraindividually by pairwise sign tests. Description was based on the intraindividual differences' medians and quantiles.

Results

Median pupil diameters were 6.67 mm for the scale pupillometer (interquartile range 6.07–6.94 mm), 6.60 mm for the dynamic pupillometer (6.0–7.02 mm), and 6.37 mm for the wavefront-based aberrometer (5.9–6.7 mm). Pairwise comparison revealed statistically significant (P<0.05), although not clinically relevant median deviations. Although no clinically relevant median differences were observed (when based on intraobserver means), deviations for single pupil diameter assessments ranged up to 1 mm.

Conclusion

No clinically relevant median deviations were observed in the underlying repeated measurement scenario. The scale pupillometer showed greater interobserver variation than the objective tests.

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Copyright information

© Springer-Verlag 2003

Authors and Affiliations

  • Sabine Schmitz
    • 1
  • Frank Krummenauer
    • 2
  • Sebastian Henn
    • 1
  • H. Burkhard Dick
    • 1
  1. 1.Department of OphthalmologyJohannes Gutenberg UniversityMainzGermany
  2. 2.Department of Medical Biometry, Epidemiology and InformaticsUniversity of MainzMainzGermany

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