Laser Treatment Monitoring with Reflectance Confocal Microscopy

Abstract

Laser treatments have become popular in Dermatology. In parallel to technologic development enabling the availability of different laser wavelengths, non-invasive skin imaging techniques, such as reflectance confocal microscopy (RCM), have been used to explore morphologic and qualitative skin characteristics. Specifically, RCM can be applied to cosmetically sensitive skin areas such as the face, without the need for skin biopsies. For these reasons, apart from its current use in skin cancer diagnosis, our systematic review reveals how RCM can be employed in the field of laser treatment monitoring, being particularly suitable for the evaluation of variations in epidermis and dermis, and pigmentary and vascular characteristics of the skin. This systematic review article aims to provide an overview on current applications of RCM laser treatment monitoring, while describing RCM features identified for different applications. Studies on human subjects treated with laser treatments, monitored with RCM, were included in the current systematic review. Five groups of treatments were identified and described: skin rejuvenation, scar tissue, pigmentary disorders, vascular disorders and other. Interestingly, RCM can assist treatments with lasers targeting all chromophores in the skin and exploiting laser induced optical breakdown. Treatment monitoring encompasses assessment at baseline and examination of changes after treatment, therefore revealing details in morphologic alterations underlying different skin conditions and mechanisms of actions of laser therapy, as well as objectify results after treatment.

Keywords: laser; laser monitoring; pigmentation; reflectance confocal microscopy; rejuvenation; scar.

Figure 1

PRISMA diagram.

Figure 2

Reflectance confocal microscopy images of a patient with striae distensae at baseline and one month after 5 CO₂ laser sessions. (A) At baseline, neat wall feature can be observed (white arrows), with hyper-reflective compact collagen and elongated papillae as well as the presence of an area of regular architecture (white star) (B) After treatment, neat-wall is not detectable and the architecture is predominantly composed of roundish papillae.

Figure 3

Reflectance confocal microscopy images of patient showing superficial melasma at baseline and 3 months after Q-switched laser treatment. (A) At baseline, mottled pigmentation (white arrow) can be observed at epidermal level (B) After treatment, RCM shows disappearance of mottled pigmentation and recover of regular honeycombed pattern.