Abstract:
Pupillometry technique has gained an increased interest over the years as it allows to
objectively assess patient’s consciousness and neuro-ophthalmological status by
measuring pupillary light reflex (PLR). Chromatic pupillometry emerged with the
discovery of intrinsically photosensitive retinal ganglion cells (ipRGCs), blue light
sensitive and contributors to PLR. Automated pupillometers have been developed over the
years to quantitatively measure PLR but have a reduced possibility to be a widespread
screening tool as they are expensive and not portable. In this study, a smartphone-based
pupillometer was developed, taking advantage of this technology accessibility, low-cost
price, and portability. Chromatic stimuli were considered in this smartphone-based
pupillometer to assess the contribution of ipRGCs to PLR and allow the screening of the
neuro-ophthalmological diseases. In this preliminary study, six healthy individuals
participated and pupillometric data was collected using the smartphone application
developed, testing different protocols and background light conditions. The system
presented good quality of eye images acquired and good behaviour in pupil data
extraction. The acquisition protocols tested showed promising results to be used for
chromatic pupillometry, although increasing the number of participants is mandatory and
further research is needed. Nevertheless, this study shows the potential of the developed
pupillometer to function as low cost, portable and accessible screening tool for neuroophthalmological
diseases.