A Comparative Study of Photoacoustic and Reflectance Methods for Determination of Epidermal Melanin Content

Viator, John A.; Komadina, Jason; Svaasand, Lars O.; Aguilar, Guillermo; Choi, Bernard; Nelson, J. Stuart

doi:10.1111/j.0022-202x.2004.22610.x

Cited by 78 publications

(61 citation statements)

References 31 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Of all skin chromophores, melanin and hemoglobin are the two predominant absorbers within the visible light spectrum. Epidermal melanin absorption decreases monotonically from the ultraviolet to the infrared range, thus causing a steady increase in the reflectance spectra of human skin towards longer wavelengths [12]. Oxyhemoglobin absorbs strongly in the 500-600 nm range and is responsible for a set of dips in the reflectance spectra at 542 and 577 nm.…”

Section: Visible Reflectance Spectroscopy (Vrs)mentioning

confidence: 99%

“…A video imaging system is used to verify bulk tissue deformation and the skin surface stretching. A visible reflectance spectroscope equipped within a vacuum chamber is used to determine the relative change in average D v and BVF of the dermis as well as the change in the epidermal absorption coefficient (m a,e ) as a function of both P v and time [12].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Laser surgery of port wine stains using local vacuum pressure: Changes in skin morphology and optical properties (Part I)

et al. 2007

Self Cite

View full text Add to dashboard Cite

Background and Objectives: In a recent case study, the use of a suction device to aid in port wine stain (PWS) laser treatments showed favorable results. It is our objective to further understand the mechanisms of vacuum-assisted laser therapy by analyzing the mechanical and optical changes of the skin and musculoskeletal tissues during the application of mild vacuum pressure from a suction cup. Study Design/Materials and Methods: A mathematical model of tissue deformation was used to determine the changes in tissue morphology that affect the underlying laser-tissue interactions, such as epidermal stretching and thinning, blood vessel dilation, and change in blood vessel depth. Video imaging experiments were used to verify the bulk tissue deformation and skin surface stretching computed by the mathematical model. Additionally, visible reflectance spectroscopy was used to determine the changes in the optical characteristics of tissue, including blood vessel dilation and epidermal absorption coefficient. Results: At a vacuum pressure of 50 kP a , the epidermis at the center of the suction cup was measured to stretch 4% and was calculated to be thinned approximately 6%. Blood vessels embedded in the dermis were measured to dilate up to two times their original size. However, these vessels were calculated to be displaced toward the skin surface by a very small amount, approximately 1-3 mm. The absorption coefficient of the epidermis was also measured to be reduced significantly by approximately 25% at a wavelength of 585 nm. Conclusions: Mild vacuum pressure applied to the skin surface causes considerable changes in the morphology and optical properties of the tissue. These changes may be used for more efficient photothermolysis of small PWS blood vessels.

show abstract

Section: Visible Reflectance Spectroscopy (Vrs)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Laser surgery of port wine stains using local vacuum pressure: Changes in skin morphology and optical properties (Part I)

et al. 2007

Self Cite

View full text Add to dashboard Cite

show abstract

“…In 2004, Viator and co-workers proposed a method for the determination of the epidermal melanin content employing a PA probe using a Nd:YAG (neodymium, yttrium, aluminum, garnet) laser at 532nm (Viator et al, 2004). Ten human subjects with skin phototypes I-VI were tested using the PA probe and visible reflectance spectroscopy (VRS); melanin content was evaluated through each of these methods, and a good linear fit (r 2 =0.85) was obtained for the plot of PA x VRS.…”

Section: Skin Pigmentation Analysis Employing Photoacoustic Measurementsmentioning

confidence: 99%

Photoacoustic Technique Applied to Skin Research: Characterization of Tissue, Topically Applied Products and Transdermal Drug Delivery

Mota¹,

Carvalho²,

Carvalho³

et al. 2011

Acoustic Waves - From Microdevices to Helioseismology

View full text Add to dashboard Cite

“…PAM has been mostly applied to quantitative inspection of endogenous chromophores, including hemoglobin and melanin [22]. Applications of PAM on epidermal melanin content quantification and melanoma imaging were investigated [23,24]. Photoacoustic ophthalmoscopy (PAOM) was developed to visualize RPE melanin in vivo, demonstrating distinct difference of RPE PA generation between normal and albino mice [25].…”

Section: Introductionmentioning

confidence: 99%

Quantifying melanin concentration in retinal pigment epithelium using broadband photoacoustic microscopy

Xiao¹,

Li²,

Dong³

et al. 2017

Biomed. Opt. Express

View full text Add to dashboard Cite

Abstract:Melanin is the dominant light absorber in retinal pigment epithelium (RPE). The loss of RPE melanin is a sign of ocular senescence and is both a risk factor and a symptom of age-related macular degeneration (AMD). Quantifying the RPE melanin concentration provides insight into the pathological role of RPE in ocular aging and the onset and progression of AMD. The main challenge in accurate quantification of RPE melanin concentration is to distinguish this ten-micrometer-thick cell monolayer from the underlying choroid, which also contains melanin but carries different pathognomonic information. In this work, we investigated a three-dimensional photoacoustic microscopic (PAM) method with high axial resolution, empowered by broad acoustic detection bandwidth, to distinguish RPE from choroid and quantify melanin concentrations in the RPE ex vivo. We first conducted numerical simulation on photoacoustic generation in the RPE, which suggested that a PAM system with at least 100-MHz detection bandwidth provided sufficient axial resolution to distinguish the melanin in RPE from that in choroid. Based on simulation results, we integrated a transparent broadband micro-ring resonator (MRR) based detector in a homebuilt PAM system. We imaged ex vivo RPE-choroid complexes (RCCs) from both porcine and human eyes and quantified the absolute melanin concentrations in the RPE and choroid, respectively. In our study, the measured melanin concentrations were 14.7 mg/mL and 17.0 mg/mL in human and porcine RPE, and 12 mg/mL and 61 mg/mL in human and porcine choroid, respectively. This study suggests that broadband PAM is capable of quantifying the RPE melanin concentration from RCCs ex vivo. 164-170 (1978). 34. S. Jacques, Optical Absorption of Melanin (Oregon Medical Laser Center, 1998). 35. T. Sarna and R. C. Sealy, "Photoinduced oxygen consumption in melanin systems. Action spectra and quantum yields for eumelanin and synthetic melanin," Photochem. Photobiol. 39(1), 69-74 (1984). 36. T. Berer, E. Leiss-Holzinger, A. Hochreiner, J. Bauer-Marschallinger, and A. Buchsbaum, "Multimodal noncontact photoacoustic and optical coherence tomography imaging using wavelength-division multiplexing," J. Biomed. Opt. 20(4), 46013 (2015). 37. M. O. Culjat, D. Goldenberg, P. Tewari, and R. S. Singh, "A review of tissue substitutes for ultrasound imaging," Ultrasound Med. Biol. 36(6), 861-873 (2010).

show abstract

A Comparative Study of Photoacoustic and Reflectance Methods for Determination of Epidermal Melanin Content

Cited by 78 publications

References 31 publications

Laser surgery of port wine stains using local vacuum pressure: Changes in skin morphology and optical properties (Part I)

Laser surgery of port wine stains using local vacuum pressure: Changes in skin morphology and optical properties (Part I)

Photoacoustic Technique Applied to Skin Research: Characterization of Tissue, Topically Applied Products and Transdermal Drug Delivery

Quantifying melanin concentration in retinal pigment epithelium using broadband photoacoustic microscopy

Contact Info

Product

Resources

About