Implications of melanopsin photoreceptor dysfunction in eye disease

Beatrix Feigl

School of Biomedical Sciences

Queensland University of Technology & Institute of Health and Biomedical Innovation

Honorary Senior Scientist, Queensland Eye Institute

Bio: A/Prof Beatrix Feigl, MD, PhD is an ophthalmologist and vision scientist. She held appointments as a medical retina specialist in the Department of Ophthalmology, Medical University of Graz, Austria and Research Fellow at the University of Tuebingen, Germany and the Smith Kettlewell Eye Institute, San Francisco, USA before joining Queensland University of Technology (QUT), Brisbane Australia. Dr Feigl is head of the Vision and Eye Program at the Institute of Health and Biomedical Innovation at QUT and her laboratory investigates effects of retinal disease on non-visual behaviours mediated by melanopsin (i.e. the pupil response, sleep and mood). With her team, she has translated their custom-developed methods to clinical settings for investigating melanopsin cell function in diabetes, glaucoma and age-related macular degeneration.


Abstract: Melanopsin expressing intrinsically photosensitive Retinal Ganglion Cells (ipRGCs) constitute the third class of photoreceptors in the eye and have roles in image and non-image forming behaviours. Since their discovery in human and non-human primate retina in 2005 (after their initial identification in mice), researchers have extensively used animal models to study their physiological functions. My research focusses on clinical investigations of melanopsin function in humans using techniques developed in our laboratory. We have demonstrated that melanopsin photoreceptors are dysfunctional in many retinal and optic nerve diseases including age-related macular degeneration, diabetic retinopathy and glaucoma. Using chromatic pupillometry, we have established the ipRGC-mediated pupil light response as an effective early biomarker of disease, even at pre-clinical and pre-perimetric stages. This presentation will summarize our findings of ipRGC function in common blinding eye diseases and neurological disorders (i.e. Parkinson’s disease). The link between ipRGC dysfunction and its implications on chronobiological behaviours (i.e. sleep) in patients will be highlighted.


Support: Australian Research Council DP-170100274


Form and function in parallel pathways for colour vision

Paul Martin

Save Sight Institute and ARC Centre of Excellence for Integrative Brain Function

University of Sydney

Bio: Paul R. Martin graduated in Physiology at Sydney in 1986. Following postdoctoral work in Germany, in 1992 he joined Faculty at the University of Sydney. From 2003 to 2010 he was Director of Research at the National Vision Research Institute of Australia and University of Melbourne. He returned to Sydney in 2010 to take up his current appointment as Professor of Experimental Ophthalmology. With co-leader Ulrike Grünert their Visual Neuroscience Research Group studies the microscopic anatomy and physiological properties of the primate retina and sub-cortical visual system.


Abstract: Paul’s abiding research interest is the structure and function of the visual system with emphasis on relation of parallel nerve pathways to color, form, and motion modalities of visual perception. His presentation will summarise evidence for distinct pathways in the retina and sub-cortical visual system that carry visual signals supporting blue-yellow and red-green axes of colour vision. These pathways emerge at the first level of visual processing in the retina, where cone photoreceptors contact bipolar cells and horizontal cells, and are carried to the brain as trains of action potentials in axons of multiple classes of retinal output neurones (ganglion cells). At the first point of interaction with brain pathways, in the dorsal lateral geniculate nucleus in the thalamus, there is anatomical and functional segregation of blue-yellow and red-green colour vision pathways. The consequences of this segregation will be discussed.



Light and color in the wild

Sylvia C. Pont

Perceptual Intelligence lab, Delft University of Technology
Industrial Design Engineering
π-lab (Perceptual Intelligence lab)
Delft University of Technology

Bio: Professor Pont graduated in Experimental Physics in 1993 at Amsterdam University. She received her PhD in 1997 at Utrecht University on the basis of a thesis on haptic perception. From 1997 to 1999 she studied computer aids at Visio, an institute for visually impaired people. Next, she returned to Utrecht University to investigate ecological optics. In 2008 she transferred her group and equipment to Delft University of Technology. Here she coordinates the Perceptual Intelligence lab (π-lab) at Industrial Design Engineering, a task-force working on real-world perception problems with a cross-disciplinary approach. Her group’s research includes studies into design, perception and optics of light and materials, of art, and haptic perception and interfaces.


Abstract: Light in natural scenes can be described as a light field. Light fields capture all there is to see in scenes. We developed methods and tools for the measurement and visualization of the first order properties of optical (physical, objective) and visual (perceptual, subjective) light fields, including their spatial and angular distributions. These methods are generic and can be used for any type of scene ("in the wild"). We found that perceptual light field structures are simplified with respect to the optical ones. They can be described by a framework, which, at a phenomenological level, agrees with Richard Kelly's popular (in practice) lighting design approach: a weighted combination of ambient, focus and texture or brilliance light layers. Currently we are extending our research to the color domain via theoretical modeling and simulation of basic color effects in 3D spaces, empirical testing and visualization. Preliminary results show the occurrence of systematic hue, saturation and brightness effects in light fields, which are relevant for, for instance, perception research, architecture and computer graphics.