title: Understanding the changes of cone reflectance in adaptive optics flood illumination retinal images over three years.
abstract: Although there is increasing interest in the investigation of cone reflectance variability, little is understood about its characteristics over long time scales. Cone detection and its automation is now becoming a fundamental step in the assessment and monitoring of the health of the retina and in the understanding of the photoreceptor physiology. In this work we provide an insight into the cone reflectance variability over time scales ranging from minutes to three years on the same eye, and for large areas of the retina (≥ 2.0 × 2.0 degrees) at two different retinal eccentricities using a commercial adaptive optics (AO) flood illumination retinal camera. We observed that the difference in reflectance observed in the cones increases with the time separation between the data acquisitions and this may have a negative impact on algorithms attempting to track cones over time. In addition, we determined that displacements of the light source within 0.35 mm of the pupil center, which is the farthest location from the pupil center used by operators of the AO camera to acquire high-quality images of the cone mosaic in clinical studies, does not significantly affect the cone detection and density estimation.
authors.affiliation: Applied Optics Group, School of Physics, National University of Ireland, Galway, Ireland.
authors.forename: Letizia
authors.initials: L
authors.lastname: Mariotti
authors.affiliation: Applied Optics Group, School of Physics, National University of Ireland, Galway, Ireland.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Devaney
authors.affiliation: Istituto per i Processi Chimico-Fisici, Consiglio Nazionale delle Ricerche, Viale F. Stagno D'Alcontres 37, 98158, Messina, Italy; Vision Engineering Italy srl, Via Adda 7, 00198 Rome, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lombardo
authors.affiliation: Fondazione G.B. Bietti IRCCS, Via Livenza 3, 00198 Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Lombardo
keywords: (110.1080) Active or adaptive optics; (170.3880) Medical and biological imaging; (330.7331) Visual optics, receptor optics