A split-face study of intense pulsed light on photoaging skin in Chinese population

Intense pulsed light (IPL) is regarded as the gold standard of nonablative photo-rejuvenation. Yet there is still a need to observe its efficacy and safety on dark skin using a split-face module.

Twenty-four Chinese women with photoaging were enrolled in this study. Patients were randomized to receive four IPL treatments at 3- to 4-week intervals on one side of face, with the other side spared as control. Changes of photoaging were evaluated using a global evaluation, an overall self-assessment, a Mexameter and a Corneometer. Skin biopsies were taken after four sessions of treatment on one side of face. The melanocyte density and the contents of melanin, collagen fibers, and elastic fibers were stained and used to evaluate the improvement on dyschromia and other signs of photoaging.

The global scores of photoaging on treated side decreased significantly from 3.02 to 1.22, while it remained unchanged on the untreated side. Twenty-one of 24 patients (87.5%) rated their improvement as excellent or good. The difference on the values of melanin index and erythema index on treated side were significantly larger than those on untreated side after the 1st session, the 4th session and at 3-month follow-up (P<0.05). The melanin contents were significantly decreased and the collagen fibers were obviously increased only on treated side (P<0.05). Adverse effects of treated side were limited to mild pain and transient erythema.

Using this split-face module, IPL treatment is proved both clinically and histologically to be effective in treating photoaging skin in Chinese population. Adverse effects were minimal and acceptable.