Tracking of cutaneous vascular structural changes post-UV irradiation using optical coherence tomography angiography

Area of Science:

• Dermatology
• Vascular Biology
• Medical Imaging

Background:

• Ultraviolet (UV) irradiation triggers skin repair mechanisms, involving blood vessels.
• Understanding in vivo vascular dynamics, like changes over time and depth, is crucial but incomplete.
• Cutaneous blood vessels are key to skin homeostasis via angiogenesis and vasodilation.

Purpose of the Study:

• To investigate the long-term effects of UV irradiation on skin vascular structures.
• To assess the depth-dependent changes in micro-vasculature following UV exposure.
• To evaluate the utility of OCTA in monitoring UV-induced vascular dynamics.

Main Methods:

• Ten Asian males received UV (UVA + UVB) irradiation at two minimal erythema doses (MED).
• Optical coherence tomography angiography (OCTA) was used for non-invasive, in vivo imaging.
• Epidermal thickness and vascular changes were monitored for 28 days post-irradiation.

Main Results:

• UV irradiation induced significant vascular dilation and epidermal thickening.
• Increased vessel density was observed from the papillary to upper reticular dermis (200 µm depth).
• These vascular changes persisted for at least 28 days.

Conclusions:

• UV irradiation causes persistent micro-vascular structural changes in the skin.
• The observed vascular effects, including dilation and increased density, lasted up to 28 days.
• OCTA is a valuable tool for assessing and monitoring in situ micro-vasculature and its dynamic changes in human skin.