Towards a normative database of the flickering chromatic pupillometry

TRIPOLONE, MARÍA CONSTANZA; AGÜERO, CARLOS; LAVAQUE, ALEJANDRO; ISSOLIO, LUIS ALBERTO; BARRIONUEVO, PABLO ALEJANDRO

San Miguel de Tucumán

Taller; InVision-T: II Taller Latinoamericano de Ciencias de la Visión; 2019

Departamento de Luminotecnia, Luz y Visión (UNT). Instituto de Investigación en Luz, Ambiente y Visión (CONICET)

Pupil light reflex (PLR) is controlled by melanopsin retinal ganglion cells, which also receive inputs from rods and cones covering the visual spectrum. Therefore the PLR can be used as a biomarker of the retina. Chromatic pupillometry is a new tool for assessing the health of the retinal circuitry. Most of the work done so far is on conventional pulse PLR, however flickering PLR can be processed in the frequency domain to easily eliminate pupil noise. In this work we presented a set of data to generate a normative database of flickering pupillometry.A dome lab-made chromatic pupillometer (fps=90Hz) with four primaries [R (λp=636nm, Lb=1.6 cd/m²); G (λp=516nm, Lb=1.7 cd/m²); C (λp=496nm, 1 cd/m²); and B (λ= 468 nm and 0.7 cd/m²)] was used. Pupillary recordings of the dominant eye were obtained when participants (10 subjects, 33.5±3.6 y.o) saw monocularly a 10-cycles sinusoidal stimulation (F=1Hz, Contrast=80%) of each primary, after a 30/60sec. adaptation period to the DC radiance value of each primary. We also obtained pupil recordings for the combination of the four primaries: BCGR. Using Fourier transformation we obtained pupil amplitude and phase in the frequency domain of each recording for the stimulus frequency (1Hz).Average results with 2 standard deviations for amplitude were B: -0.92±0.56, C: -1.03±0.56, G: -1.04±0.56, R: -0.91±0.53, and BCGR: -0.84±0.52 in log mm and for phases were B: -27.7±82.7, C: -55±89.7, G: -49.2±54.6, R: -51.2±53.7, and BCGR: 133.6±77 in deg. All primaries recordings were delayed around 500ms from BCGR recordings.We obtained pupil results for chromatic flickering stimulation for a young age range from 20-40 y.o., next step is to increase this range with older subjects. To our knowledge this is the first normative database of chromatic flickering pupillometry, which can be useful to identify retinal diseases, using the pupillary light reflex as biomarker.