FOITS (Fast Optical In-vivo Topometry of human Skin): New approaches to the 3D analysis of surface structures of human skin

Based on the surface roughness standards used in the metal-working industry , it uses computer-assisted strip analysis to process information gathered from high-speed, non-contact scanning. It is possible to visualise the math ematical data in 3D form. So far, surface relief parameters have had to be acquired indirectly by first making silicone casts of the skin and then dig italising them with image analysis, mechanical scanners or, more recent, la ser profilometry and confocal microscopy. We selected the roughness parameters R-a, R-z and R-max (DIN defined) and " positive" and "negative" Volume to describe the skin surface. In 40 healthy volunteers we were able to define significant intra-individual differences in these roughness parameters, which were correlated with the location of the area of skin being scanned (p < 0.05). When healthy areas of skin were compared with areas of chronic eczema in 10 patients with neurodermatitis t he differences in the above-mentioned roughness parameters were just as str iking (p < 0.05). In patients with chronic atopic eczema there was a statis tically significant correlation between changes in the parameters "positive " and "negative" volume, and the smoothing of the skin seen after 14 days o f treatment with standard ointments (p < 0.02). Apart from its industrial uses, we see potential applications for FOITS in the investigation of quantitative and qualitative aspects of aging processe s, physiological and pathological processes in the skin, and the effect of topical preparations applied to the skin.