Current tools for skin imaging and analysis

The main purpose of skin analysis was to acquire information about its morphology, histology, and function. The oldest and primary tool still used by dermatologists and physicians for skin examination and skin disease identification is the ‘‘naked eye.’’ However, human perception is limited; first, it allows assessment of only the skin surface and secondly, it depends on the ability that varies from individual to individual. Histologic examination of biopsies or mechanically removed slices can be used for more advanced skin investigation, but these methods have many drawbacks. First, they are invasive, requiring the removal and preparation of tissues for further analysis, usually microscopic. The process of sample preparation can result in the changes in the sample, e.g. water loss or mechanical damages. In addition, the test cannot be repeated as the sample is destroyed in the process. Great progress in optics, electronic engineering, and computer science over a few years has placed particular emphasis on the necessity to develop new non-invasive, non-destructive methods of analysis of tissues in vivo because significant differences between in vivo ⁄ in vitro assessment may occur. The structure of the skin layers, their chemical composition, and distribution of compounds can be determined using new methods of skin investigation. In addition, traces of skin penetration process of topically applied substances can be analyzed qualitatively and quantitatively. Such in-depth analysis is very useful in the development of modern drug products for skin applications and effective cosmetics. In addition, non-invasive diagnostic methods of skin diseases, such as skin cancers, are now widely available, which is invaluable, especially in the quick diagnosis of early stages of malignant tumors.