Correlations Between Light Penetration into Skin and the Therapeutic Outcome Following Laser Therapy of Port-wine Stains

Abstract

For several years the flashlamp-pumped pulsed dye laser (FPDL) has been the favoured method for the treatment of port-wine stains (PWS). The therapeutic outcome of FPDL laser therapy depends on the anatomical location of the PWS and is mainly attributed to morphological parameters such as size and depth of the PWS blood vessels. The aim of this study was to show a correlation between the therapeutic outcome following FPDL therapy and the optical properties of the skin overlying the PWS vessels. For this purpose the therapeutic outcome following FPDL treatment (585 nm; 0.45 ms) of 884 PWS situated on different body sites was evaluated by judging the grade of fading of PWS colour. On the other hand the light penetration into 123 skin samples (thickness 0.10-1.35 mm) was determined between 450 nm and 1030 nm and compared with the PWS laser therapy outcome for equal locations by statistical analysis. PWS on the neck, trunk, arms or legs yielded a higher mean grade of fading as compared to PWS on the head. Within the face, a wide range of fading was evident. The light penetration into skin increased linearly with increasing wavelength and location-dependent differences were found. The attenuation coefficient was 22.8+/-5.3 mm(-1) at 585 nm. No significant or strong correlation was observed between the therapeutic outcome of PWS laser therapy and the light penetration into skin. However, a correlation was obvious by plotting the respective profile plots. Therefore, among other effects, in particular morphological parameters of PWS vessels, the optical properties of the skin contribute to a small extent to the clinical outcome of PWS laser therapy.

Simulating light transport through skin for color prediction of port wine stain lesions: a review

“…This may be appropriate in clinically normal pale skin types, as the probability of scattering within the skin may be as high as twenty times that of absorption. 10,44 However, absorption is much greater in the epidermis of darker skin types, the blood vessel plexi of the normal dermis, and within PWS lesions. Thus, the validity of this approximation is limited in such cases.…”

Upconversion nanoparticles conjugated with curcumin as a photosensitizer to inhibit methicillin-resistant Staphylococcus aureus in lung under near infrared light

“…1 It mainly takes effect by phototoxicity through production of singlet oxygen ( 1 O 2 ) upon irradiation at 450 nm to kill bacteria and tumors. 2,3 Because the penetration of the laser light depends on its wavelength, 4 450 nm has weaker penetration than red light and near infrared light (NIR), leading to feeble action on deep lesions in vivo.…”

“…7 For most UCNPs, lanthanide ion codoped sodium yttrium fluoride (NaYF 4 ) nanoparticles possess one of the highest upconversion efficiencies, with tunable photoluminescence, controlled size, and low toxicity. 8 To convert NIR to 450 nm light, we prepared NaYF 4 UCNPs to conjugate with curcumin as a photosensitizer to take effect in deep tissues. The physicochemical properties of the UCNPs, including particle morphology, size distribution, differential scanning calorimetry (DSC), and 1 O 2 production, were analyzed.…”

Application of the critical angle method to refractive index measurement of human skinin vivounder partial contact

“…It also defines the characteristics of light reflection from skin. Therefore, it has been recognized as an important parameter in applications such as laser therapy 1 and cosmetics. 2 Various methods have been developed for measuring RI.…”

“…Application of the critical angle method to refractive index measurement of human skin in vivo under partial contact 1 …”