Berlin 2012 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 18: Posters: Statistical Physics in Biological Systems

BP 18.18: Poster

Mittwoch, 28. März 2012, 17:30–19:30, Poster A

Reduction of Scattered Light by Müller Cells in the Human Retina — •Oliver Bendix, Ragnar Fleischmann, and Theo Geisel — Max Planck Institute for Dynamics und Self-Organization, Göttingen, Germany

It is a long standing question why in the mammalian eye photoreceptors are positioned at the back of the retina, forcing photons to travel through various neuronal layers of the retina before the light-sensitive rods and cones can detect them. Recent studies suggest that certain retinal glial cells – called Müller cells (MCs) – play an important role in answering that question. Recent experiments have suggested that MCs extracted from the retina can act as optical fibers [1].
To understand the light guiding properties of the MC in the natural fluctuating optical environment, we developed a model to analyze the light reflection and transmission of MCs embedded in a random medium neuronal tissue. With these quantities and a simplified geometrical eye model we study how light is scattered in the eye. We found that MCs can lead to a substantial increase of the signal-to-noise ratio (SNR), the ratio of the intensity of direct incident light at a photoreceptor to the intensity of back-scattered light from other areas of the retina. The SNR is most pronounced in the vicinity of the fovea and can be more than an order of magnitude.

References
Franze et. al., Müller cells are living optical fibers in the vertebrate retina. Proc. Natl. Acad. Sci. U.S.A. 104, 2007.