Assessing Repeatability of Pupillometric Measurements in the Eyes of Refractive Surgery Candidates Using Infrared Pupillometer

Abstract

PURPOSE: To assess the repeatability of measuring pupil dynamics using an infrared pupillometer. METHODS: A total of 124 eyes of 124 patients scheduled for corneal laser refractive surgery were separated into myopic and hyperopic groups and further subdivided based on high or low levels of astigmatism. Measurements were taken using dynamic pupillometry (Topolyzer Vario; Alcon Laboratories, Inc., Sinking Spring, PA). Main outcome measures were pupil diameter size, the distance between the pupil center and the keratoscopic axis, and the spatial shift of the pupil center. Repeatability of measurements was assessed from test–retest repeatability (2.77 Sw), coefficient of variation, and intraclass correlation coefficient (ICC). RESULTS: The 2.77 Sw of all measured parameters was lower than 0.36 and 0.44 mm for myopic and hyperopic eyes, respectively. ICCs of the pupil diameter measurements were higher than 0.963 and 0.926 in myopic and hyperopic eyes, respectively. ICCs of the distance between the pupil center and the corneal vertex along the x-axis were higher than 0.934 and 0.994 in myopic and hyperopic eyes, respectively. Along the y-axis, ICCs of this distance were higher than 0.417 in myopic eyes and higher than 0.504 in hyperopic eyes. The pupil center shift measurement ICCs were lower than 0.482 and 0.526 for myopic and hyperopic eyes, respectively. CONCLUSIONS: In all groups, the Topolyzer Vario showed excellent repeatability when measuring pupil dynamic parameters except when measuring pupil center shift and distance between the pupil center and the corneal vertex along the vertical axis. [ J Refract Surg. 2017;33(8):552–557.]