Capillary Refill-The Key to Assessing Dermal Capillary Capacity and Pathology in Optical Coherence Tomography Angiography.

BACKGROUND/OBJECTIVES: Standard optical coherence tomography angiography (OCTA) has been limited to imaging blood vessels actively undergoing perfusion, providing a temporary picture of surface microvasculature. Capillary perfusion in the skin is dynamic and changes in response to the surrounding tissue's respiratory, nutritional, and thermoregulatory needs. Hence, OCTA often represents a given perfusion state without depicting the actual extent of the vascular network. Here we present a method for obtaining a more accurate anatomic representation of the surface capillary network in human skin using OCTA, along with proposing a new parameter, the Relative Capillary Capacity (RCC), a quantifiable proxy for assessing capillary dilation potential and permeability. METHODS: OCTA images were captured at baseline and after compression of the skin. Baseline images display ambient capillary perfusion, while images taken upon capillary refill display the network of existing capillaries at full capacity. An optimization-based automated vessel segmentation method was used to automatically analyze and compare OCTA image sequences obtained from two volunteers. RCC was then compared with visual impressions of capillary viability. RESULTS: Our OCTA imaging sequence provides a method for mapping cutaneous capillary networks independent of ambient perfusion. Differences between baseline and refill images clearly demonstrate the shortcomings of standard OCTA imaging and produce the RCC biometric as a quantifiable proxy for assessing capillary dilation potential and permeability. CONCLUSION: Future dermatological OCTA diagnostic studies should implement the Capillary Refill Methods over standard imaging techniques and further explore the relevance of RCC to differential diagnosis and dermatopathology. Lasers Surg. Med. © The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals, Inc.

Laser treatment of hyperpigmented lesions: position statement of the European Society of Laser in Dermatology.

BACKGROUND: Lasers and intense pulsed light sources (IPLS) are proposed for the treatment of many pigmentary disorders. They are sometimes considered as magic tools able to remove any type of lesions. Although being the best option for several hyperpigmented lesions, they can also worsen some conditions and have potential side-effects. OBJECTIVE: The aim of this review was to give evidence-based recommendations for the use of lasers and IPLS in the treatment of hyperpigmented lesions. METHODS: These recommendations were produced for the European Society of Laser Dermatology by a consensus panel made up of experts in the field of pigment laser surgery. Recommendations on the use of lasers and light treatments were made based on the quality of evidence for efficacy, safety, tolerability, cosmetic outcome, patient satisfaction/preference and, where appropriate, on the experts' opinion. RESULTS: Lasers and IPLS are very effective for treating many hyperpigmented lesions such as lentigos, dermal hypermelanocytosis or heavy metal depositions. In the other hand, they have to be considered with great caution for other disorders, such as café au lait macules, melasma or postinflammatory hyperpigmentation. After making the correct diagnosis, if lasers or IPLS are indicated, the optimal wavelengths and parameters will be chosen taking into account the skin phototype, origin and depth of the target pigments. CONCLUSION: Although potentially very effective, lasers and IPLS cannot be proposed for all types of hyperpigmented lesions. In all cases, precise recognition of the disorder is mandatory for choosing between these devices and other therapeutic approaches.