Our overarching goal is to inquire photoreceptor physiology during visual stimulation of the living retina through advanced optical techniques. In the long term, we aim to advance noninvasive ophthalmic diagnostics in this way.

Physiological processes lead to small but quantifiable local variations in the intrinsic optical signature of the retina, such as reflectance, scattering, fluorescence, etc. The eye offers an unobstructed view onto the retina and an ideal opportunity to observe and record from this tissue in a noninvasive manner.

One major challenge we are tackling is the objective assessment of visual cycle activity in rod and cone photoreceptors and the quantification of their mutual interaction. As functional and metabolic processes take place in the photoreceptors, highly efficient fluorophores are generated. By exciting these fluorophores via nonlinear absorption and capturing their fluorescence, we aim to interrogate the biochemistry of photoreceptors during visual cycle activity in their natural environment. At the same time, we correlate these objective measurements to the subjects’ visual experience. To this end, we make strong use of adaptive optics instruments. Custom-engineered adaptive optics scanning light ophthalmoscopes (AOSLOs) can nowadays routinely resolve single rod and cone photoreceptors (smallest diameter ~1 µm) and target these cells for imaging or single-cell psychophysics.

This group is currently being established.