Radiofrequency facial rejuvenation: evidence-based effect

Abstract

Background: Multiple therapies involving ablative and nonablative techniques have been developed for rejuvenation of photodamaged skin. Monopolar radiofrequency (RF) is emerging as a gentler, nonablative skin-tightening device that delivers uniform heat to the dermis at a controlled depth.

Objective: We evaluated the clinical effects and objectively quantified the histologic changes of the nonablative RF device in the treatment of photoaging.

Methods: Six individuals of Fitzpatrick skin type III to IV and Glogau class I to II wrinkles were subjected to 3 months of treatment (6 sessions at 2-week intervals). Standard photographs and skin biopsy specimens were obtained at baseline, and at 3 and 6 months after the start of treatment. We performed quantitative evaluation of total elastin, collagen types I and III, and newly synthesized collagen using computerized histometric and immunohistochemical techniques. Blinded photographs were independently scored for wrinkle improvement.

Results: RF produced noticeable clinical results, with high satisfaction and corresponding facial skin improvement. Compared with the baseline, there was a statistically significant increase in the mean of collagen types I and III, and newly synthesized collagen, while the mean of total elastin was significantly decreased, at the end of treatment and 3 months posttreatment.

Limitations: A limitation of this study is the small number of patients, yet the results show a significant improvement.

Conclusions: Although the results may not be as impressive as those obtained by ablative treatments, RF is a promising treatment option for photoaging with fewer side effects and downtime.

Fig 1

Clinical evaluation of volunteers in response to monopolar radiofrequency treatment. A, Representative photographs of periorbital and forehead areas at baseline, end of treatment, and 3 months posttreatment. B, Volunteers’ evaluation rates showed mean percent improvement of skin tightening (lane 1), skin texture (lane 2), rhytides (lane 3), and overall satisfaction (lane 4) at end of treatment (green) and 3 months posttreatment (red) relative to baseline. C, One volunteer developed slight erythema and mild transient hyperpigmentation 2 days after fourth session (left), which subsided 5 days later (right).

Fig 2

Radiofrequency treatment enhances epidermal hyperplasia. Skin biopsy specimens were formalin fixed and paraffin embedded. Tissue sections were stained with hematoxylineosin, showing increased thickness of epidermis and granular cell layer (brackets) associated with development of rete ridges (arrows) after RF treatment.

Fig 3

Volunteers treated with monopolar radiofrequency showed decrease in total dermal elastin. A, Skin tissues at baseline, end of treatment, and after RF treatment were immunostained for total elastin. Representative samples show decrease in elastin level. Area (rectangle) was used to assess elastin staining level. *Grenz zone. B, Percent of dermis occupied by elastin showing significant decrease in total elastotic material after treatment. *P ≤ .05. C, Verhoeff-van Gieson special stain showing similar decrease in elastic fibers after RF treatment.

Fig 4

Increase in dermal collagen content in response to radiofrequency. A, Immunohisto-chemical staining of skin tissues at baseline (left), end of treatment (middle), and after RF treatment (right) for total collagen (top) and collagen types I (middle) and III (bottom). Increase in collagen band thickness at dermoepidermal junction was observed after RF treatment compared with baseline (arrows). B, Collagen level was measured and values presented as percentage of dermis-positive collagen. Data showed statistically significant increase in both collagen I and III in response to RF. *P ≤ .05; **P ≤ .001.

Fig 5

Increase in newly synthesized collagen content in response to radiofrequency treatment. Representative examples of skin tissues stained with picrosirius red viewed under bright field (top) and polarized field (bottom). Bright field captures total collagen content. Polarized light showed yellow to orange birefringence reflecting newly synthesized collagen in yellow and total collagen in red. Note increase in newly synthesized collagen as reflected by yellow after RF treatment.