Laser fluorescence spectroscopy and optical tissue oximetry in the diagnosis of skin fibrosis

Abstract

There are currently no effective measures to combat fibrosis in modern medical practice. One of the reasons for that is the late diagnosis associated with the lack of available clinical biomarkers and effective methods of non-invasive detection of the process. Fibrosis of the skin is characterized by fibrosis of the dermis, underlying tissues and is represented by a wide range of nosologies. Scleroderma and scars are of the greatest interest for the study. Skin changes in the development of bleomycin-induced fibrosis was studied in the experimental model using laser fluorescence spectroscopy and optical tissue oximetry. A significant increase in the rates of endogenous fluorescence of porphyrins, caused by inflammation and hypoxia, was detected at 7 and 21 days. An increased intensity of endogenous collagen fluorescence and a decreased specific oxygen uptake due to excess accumulation of the extracellular matrix were recorded on the 21st day after bleomycin treatment. Synchronous measurements of the collagen fluorescence and the specific oxygen uptake allowed to correlate the obtained data and the phases of the fibrogenic response described morphologically. The results allow to judge the severity of inflammation and hypoxia in the process of the fibrosis development. The objective and quantitative nature of the recorded parameters makes it possible to develop criteria for diagnosing the phases of fibrosis development.

Keywords

• fibrosis
• laser fluorescence spectroscopy
• optical tissue oximetry
• diagnostics in vivo