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Prof. Ozzy Mermut
Department of Physics and Astronomy,
York University

Abstract

Approximately 2.2 billion people suffer globally from some form of vision impairment or blindness with most of these individuals being over the age of 50 years.  Vision diseases acutely and severely affect the quality of life, especially in the elderly.  One common disorder, age-related macular degeneration, is the leading cause of vision loss for older adults.  In our group we are studying biophotonic techniques for the early detection of hallmark biomarkers associated with retinal tissue degeneration, and investigating improved laser therapy approaches which aim to selectively target lesioned tissue to improve individualized treatment outcomes in maculopathy and cancer.  In this talk, I will present our recent biophotonic advances in early hypoxia detection, as well as new targeted laser therapy methods for these debilitating diseases. One of our photonic biosensing approaches includes sensitive, molecular-scale measurements of hypoxia – a characteristic pathophysiological property of vision diseases and tumours.  Real-time, in situ hypoxia monitoring is key to effective evaluation of the aggressiveness of a diseased lesion and its treatment resistance.  I will also present our research and development of advanced therapies based on sub-microsecond laser pulse shaping methods, which enable thermomechanical stress confinement of delivered energy to the lesion target whilst spatially limiting collateral damage to surrounding healthy cells.  Achieving quantitative dosimetry, our results from photoacoustic detection of micro-cavitation (vapourized bubbles) in photomechanical therapy mechanisms, as well as dosimetry from radical oxygen species in photochemical processes (photodynamic therapy), will be discussed.  Our recent explorations in weak magnetic field perturbations in photosensitizer fluorescence lifetime show proof-of-concept of a promising new avenue for the quantification of the oxygen micro-environment during oxygen-mediated phototherapy, with possibility of real-time molecular feedback during laser treatment.

Timbits, coffee, tea will be served in STI A before the colloquium. The colloquium speaker will be presenting remotely.