The effect of melanin on in vivo optical coherence tomography of the skin in a multiethnic cohort.

BACKGROUND: Noninvasive real-time assessment of living tissue is quickly becoming invaluable for bolstering histologic and dermatoscopic measures of cutaneous conditions. While many skin researchers have explored the utility of noninvasive imaging in inflammatory and malignant skin conditions, there is yet to be a definitive and direct assessment of the effects of melanin on the quality of optical coherence tomography (OCT) imaging and its accuracy in multiethnic patient populations. We conducted a study to evaluate the effects of melanin on the quality of in vivo OCT imaging.

METHODS: Volunteers of all Fitzpatrick skin types were imaged once in five skin regions. Images were analyzed for quality, defined quantitatively as depreciation of light as it passes through the depth of skin, and qualitatively as depth and contrast ranked by blinded clinicians.

RESULTS: Our analysis of sixteen subjects shows that there is a significant difference in quantitative OCT image quality between light (Fitzpatrick I-III) and dark (IV-VI) skin types for both epidermal (p 0.0328) and dermal levels (p 0.0021). However, there was no significant difference in qualitative blinded rater measures of image clarity (p 0.11) or perceived depth (p 0.13).

CONCLUSION: Based on our definition of image quality, our study shows that OCT images taken from darker skin types have slightly lower quality than those taken from lighter skin. However, because blinded rater assessment showed no differences in clarity or perceived depth, we conclude that OCT may be used without hesitation for manual visualization of skin and its appendages in all Fitzpatrick skin types. Further studies are required to more extensively characterize the effects of melanin on OCT imaging. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.