Research published in the October 1 issue of Optics Letters, a journal of the Optical Society of America, describes a new technique for noninvasively measuring the level of skin damage from sun exposure and aging. The initial results suggest that women’s skin ages faster than men’s.

Researchers at Friedrich Schiller University in Jena, Germany; at the Fraunhofer Institute of Biomedical Technology in St Ingbert, Germany;  and at JenLab GmbH, a Jena-based laser technology company, tested the technique directly on the forearms of 18 patients, measuring the collagen/elastin factor. The team also obtained images of tiny swaths— 0.33 mm wide—of the proteins’ fibrous matrices, showing the physical appearance of the dermis, the white lower-layer of skin that gets exposed in deep abrasions.

Large variations appeared from patient to patient, and even from one part of a patient’s forearm to another.

“In a healthy 35-year-old, some areas can appear like the skin of a 25-year-old, and others like that of someone who’s 50,” says Johannes Koehler, MD, a dermatologist at Friedrich Schiller University and a coauthor of the Optics Letters paper. “But on average, both the collagen and elastin factor and the physical appearance of the network showed a clear dependence on the patients’ age. The dependence appeared to be sex-dependent, with women’s skin losing collagen at faster rates than men’s.”

The two methods combined in the imaging technique use the ability of ultrabrief pulses of laser infrared light to stimulate tissues to emit light at shorter wavelengths—blue in the case of collagen, and green in the case of elastin. Since the epidermis is virtually transparent to infrared light, the infrared laser can reach the dermis with intense pulses of light without damaging the upper layers. By two different quantum processes, collagen and elastin will then respond by glowing blue and green.

Currently, dermatologists who want to look into the collagen network of a patient’s dermis need to remove a sample of tissue and analyze it in the lab, under a microscope or by other methods. In particular, it is impossible to monitor variations in the very same spot as aging progresses.

Although the technique is still at the experimental stage, the authors hope that someday it could become useful in studying skin diseases that affect the collagen structure.

[newswise.com, October 3, 2006]