Abstracts of the American Society for Laser Medicine and Surgery 30th Annual Conference. Phoenix, Arizona, USA. April 16-18, 2010.

OPTIMIZED IPL PHOTOCOAGULATION BY METHAEMOGLOBIN GENERATION FROM WHOLE BLOOD Caerwyn Ash, Peter Bjerring, Sean Lanigan, Marc Clement, Godfrey Town School of Medicine, Swansea University Swansea, United Kingdom; Molholm Hospital Vejle, Denmark; Skin Clinics Birmingham, United Kingdom Background: Embarrassing or disfiguring cosmetic disorders such at varicose veins, port wine stains, spider nevus can cause serious concerns to a subject. Many commercially available IPL’s used for vascular clearance use double or triple pulses without explaining the reason why such pulse patterns produce better results. The purpose of this study is to optimise output parameters to generate safer, less aggressive treatments presenting less adverse reactions, greater patient comfort, and ultimately shorter clearance times. Study: Glass capillary tubes were filled with oxygenated blood and irradiated with broadband light (530–1100 nm) of various pulse durations and fluence. Absorption spectra was collected using an Ocean Optics (HR2000+, B.V, Duiven, The Netherlands) fibre optic spectrometer optimized for wavelengths between 180–1150 nm and an iPulse i400 IPL system (Energist, Swansea). Results: Optical properties of haemoglobin changed during irradiation of broadband light due to thermally produced methaemoglobin and a Bathochromic shift to higher wavelengths as a result. Results present optimum fluence and pulse duration for methaemoglobin generation. Such a shift in absorption properties of blood can be taken advantage by a light source which produces a range of wavelengths that covers the spectral range of oxy, deoxy and methaemoglobin. Conclusion: But intentionally generating methaemoglobin in blood with a pre-treatment pulse, then specifically targeting the methaemoglobin, deeper target structure can be destroyed due to the longer wavelengths used by the IPL system with respect to a 585 nm laser. Such a mechanism also implies a reduction in the total radiant fluence required for treatment when the target chromophore changes from oxy to methaemoglobin, thus a reduction in potential adverse side effects and pain associated with the procedure, a great benefit especially in paediatric cases. #2