Research and Development of a Single Photon Counting "In Vivo Cam” for Diagnosis

This collaborative project aims the research and development of an innovative, highly sensitive, in vivo camera for diagnosis of eye disorders. A prototype of this single photon counting camera (LINCam) has been developed by our collaborators from Photonscore GmbH. This camera is able to detect auto-fluorescence in live cells in vitro with very low light intensity (<50 mW/cm²) and without any additional labelling of the cells. These preliminary observations are very promising for our aim to detect eye disorders in rats and patients in vivo through fluorescence lifetime imaging by time-correlated single-photon counting (FLIM) as a very mild procedure. In order to employ this technique in vivo, we would like to benefit from our experience in ‘in vivo confocal neuroimaging’ (ICON). This well-established method was first described by Sabel et al. Nature Medicine, 1997 and can be used to detect pre-labelled retinal ganglion cells in narcotised rats. Initial comparison of both techniques will help us to determine parameters for in vivo imaging optimisation with the new camera. Therefore, subcellular changes need to be identified, the survival of sensitive cells such as neurons needs to be monitored and long term imaging effects need to be defined under normal and pathological conditions. Further development of a user friendly software tool will finally lead to the production of an EYECam prototype, which should not just be usable for basic research on eye structures in animals, but also as prototype for an eye diagnosis system usable for future patients.