Methods of Quantitative Assessment of the Response of Dilated Skin Blood Vessels to High-Energy Light Treatments

Background: The techniques of choice used in the treatment of extensive vascular lesions of the face are methods based on high-energy light sources, such as lasers and IPL (intense pulsed light). The techniques commonly employed to detect blood vessel abnormalities in skin primarily rely on semi-quantitative or qualitative scales. Methods: The study was conducted on a group of 38 volunteers; a series of three treatments was performed using an IPL source (Lumecca, Inmode, Israel). The vessels' response to the high-energy light was verified using the following quantitative methods: mexametric measurements, hyperspectral imaging, and directional reflectance measurements. Results: In the mexameter measurement, statistically non-significant differences were obtained in the hemoglobin content in the skin condition prior to and following multiple intense pulsed light sessions. Studies performed using a hyperspectral camera showed that at a wavelength of 580 nm, the increase in skin reflectance after the treatment was statistically significant. Total directional reflectance measurements showed that at wavelengths of 400-540 nm and 480-600 nm, following the IPL treatment, the skin reflectance increased statistically significantly. Implementing three consecutive intense pulsed light procedures appears adequate to obtain a clinically satisfactory reduction in vascular changes in the facial skin. Mexametric measurements do not enable the assessment of the reaction of blood vessels to IPL. Conclusions: Hyperspectral imaging is an effective method for the quantitative assessment of skin vascular lesions. The best results in the assessment of vascular lesions using hyperspectral imaging are obtained at wavelengths of 420 nm and 580 nm. The hemispheric directional reflectance method allows for a quick, accurate, and repeatable assessment of vascular skin changes.