First results of automated RAPD-SWIFT method in dynamic pupillometry

Abstract

===============================Background. This paper presents preliminary observations on the use of a commercial pupillometric instrument (Albomed PupilX) for the detection and quantification of Relative Afferent Pupillary Defect (RAPD). In this pilot study, video-based pupillometry was used in conjunction with calibrated LED illumination to simulate the effects of the traditional swinging-flashlight test using neutral density filters.

Reproducibility and normal values of static pupil diameters

“…For the measurements at hand, only binocular illumination was used, as it is the natural form of illumination. The spectrum of the white light LED used for pupil illumination and stimulation contains an excess of blue light compared to normal daytime illumination (18). The blue light component of the illumination could reduce the amplitude of pupillary contraction for young subjects (<46 years) and increase the amplitude for older subjects compared with daylight (22).…”

“…The illumination is applied through a 36 × 24 mm field, which corresponds to a field of view of 48° × 33° for each eye. Two focus-free video cameras capture images of both eyes simultaneously with an operating frequency of 30 frames per second (18). The pupil is detected and measured in real time with a spatial resolution of 45 μm per pixel (520 × 390 pixels) (18).…”

“…Two focus-free video cameras capture images of both eyes simultaneously with an operating frequency of 30 frames per second (18). The pupil is detected and measured in real time with a spatial resolution of 45 μm per pixel (520 × 390 pixels) (18). The measurement range for pupil diameters goes from 1.5 mm to 9.0 mm.…”