Abstract
Abstract: :
Purpose: To characterize the distribution of pupil size under three different levels of scotopic and mesopic luminance. Methods: Refractive patients were evaluated preoperatively with the Procyon Pupillometer PS2000SA (Keller, Boomail, PA). Pupil size was measured at three different levels of luminance: mesopic high (4.0 Lux), mesopic low (0.40 Lux) and scotopic (0.04 Lux). Dynamic images were acquired of each eye and objectively analyzed by the PupilFitTM software. Pupil size was also acquired with Corneal Topography (Humphrey Atlas 992 version A9 San Leandro, CA). Results: Eighty-one patients (mean age 43 years +/- 10.8 [SD]) were evaluated with the Procyon pupillometer and corneal topography. A total of 169 eyes were analyzed, including 85 right eyes and 84 left eyes. The median pupil sizes measured with Procyon on right eyes were 6.6 mm +/- 0.9 (scotopic), 5.7 mm +/- 1.01 (mesopic low), and 4.1 mm +/- 0.8 (mesopic high). Median pupil size in the right eye measured with corneal topography was 3.6 mm +/- 0.7. Pupil measurements with the Procyon instrument on the left eyes were 6.5 mm +/- 0.9 (escotopic), 5.5 mm +/-0.9 (mesopic low), and 4.10mm +/- 0.8 (mesopic high). Median pupil size measured with corneal topography in the left eyes was 3.7 mm +/- 0.7. Conclusions: Pupil measurements obtained with corneal topography most closely approximated high mesopic pupil size measurements with the Procyon pupillometer. The Procyon instrument provides a more reproducible way of measuring pupil size at specific levels of light.
Keywords: pupil • imaging/image analysis: clinical • image processing