Hallmarks of old skin, caused by the natural aging of skin cells include wrinkles, dryness, and a translucent and fragile appearance. But while the mirror reveals to most of us the signs of lost youth when we peer into the mirror each morning, scientists do not have a standardized way to measure the extent of age damage in skin.
Now a group of Taiwanese researchers has used a specialized microscope to peer harmlessly beneath the skin surface to measure natural age-related changes in the sizes of skin cells. The results, which are published in the Optical Society's (OSA) open-access journal Biomedical Optics Express
, can be used to study the general phenomenon of skin aging and may help provide an index for measuring the effectiveness of 'anti-aging' skin products.
In the study, Chi-Kuang Sun, a distinguished professor at National Taiwan University and chief director of the university's Molecular Imaging Center, along with medical researcher and dermatologist Yi-Hua Liao and colleagues, evaluated 52 subjects ranging in age from 19 to 79 years old. The researchers focused a brief burst of infrared laser light into the skin of the subjects' inner forearms, an area that is generally protected from sun damage, which accelerates natural aging. The beam penetrated to a depth of about 300 millionths of a meter, or approximately where the epidermis (the upper layer of skin) and the dermis (the lower layer) meet.