Can non-contact SIAscopy be used in the diagnosis and quantification of pigmentary skin changes associated with photodamage?

• Main Author: Walls, Joseph
• Published: University of East Anglia 2012
• Subjects: 610
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.572091

Introduction: Non-contact SIAscopy is a new imaging technique where a standard polarised photographic image of the skin is decomposed to produce independent colour, blood and melanin images using SIAscopy (a form of reflectance spectroscopy). Photodamage is a product of the physiological changes caused by chronic sun exposure on the skin. Measuring the extent of photodamage has always been difficult, with most analysis requiring subjective user interpretation of results. No one available method appears better at clearly identifying and quantifying photodamage within the skin and no truly objective method exists which enables automatic measurement of these characteristics without expert evaluation. Methods and results: 1140 images of skin of various ages and levels of damage were acquired using standard digital colour photography obtained through crossed polarising filters. The sample was split into a model and test set and analysis algorithms were employed to quantify features including dyspigmentation, sallowness, erythema and vessel dilation. Relevant features were isolated and the relationship with age was determined using linear regression. From this a predictive skin photodamage age was generated and tested with a sample set of images. Conclusions: Specific pigmentary characteristic of photodamage can be identified and quantified using non-contact SIAscopy. It is an independent, repeatable, robust and inexpensive method of assessing the level of photodamage from a standard digital photograph and the results can be used to identify individuals most at risk of developing skin cancers.