<title>Optical properties of melanin in the skin and skinlike phantoms</title>

Abstract

Experimental study and computer modeling were used to investigate the optical properties of melanin in the skin and skinlike phantoms. To investigate light scattering by melanosomes in skin we made skin-like phantoms on the base of gelatin with different content of melanin particles. Spectra of total transmittance and diffuse reflectance of the phantoms were obtained in the wavelength range from 400 to 800 nm. Absorption and reduced scattering coefficients of melanin were calculated. Mie theory was used to estimate the optical properties ofmelanin particles. Wavelength dependence of refractive indices of eumelanin particles (isolated and purified from the ink of the cuttlefish Sepia officinalis) and synthetic melanin particles was estimated.

Optical properties of human skin

“…Melanin has been shown to contribute significantly to the degree of scatter within the epidermis. 58,59 As well as the volume fraction, the distribution and size of melanin structures in the epidermis also vary with skin type. Thus, the total amount of scatter that occurs as a result of melanin in the epidermis can vary substantially between individuals, 60,61 although this is not always taken into account when simulating the effects of varying melanin concentration on skin color, 42,62 or when simulating laser treatments, 15,63 for example.…”

A new Monte Carlo program for simulating light transport through Port Wine Stain skin

“…Although the spread of melanin through the simulated epidermis differed due to the differences in the initial skin models, the final prediction from the two experiments were similar overall ( Table 2). The melanosome diameters predicted from the two experiments were identical, although they were greater than expected these skin types [12][13][14][15][16].…”

“…The layer representing the living epidermis in Meglinski and Matcher's work was divided into two layers in the new programme in order to facilitate differences in melanin properties (Table 1). Estimations of representative melanosome concentrations and sizes were based upon an analysis of the literature [11][12][13][14][15][16]. [14].…”

“…During minimisation, stratum corneum granule diameter was limited to a minimum of 1 nm and a maximum of 20 nm [14,16] whilst melanosome size in the living epidermis was allowed to vary from 30 nm to 400 nm [12][13][14][15].…”

Diffraction of electromagnetic wave on skin blood vessel: Statement of the problem

“…Radiation incident from air firstly goes through the epidermis where the largest dielectric constant corresponds to the melanin. By virtue of this, optical properties of the epidermis can be considered equal to those of the melanin with refractive index of 1.44 [3]. The next layer in the skin tissue is dermis.…”