Skin Tightening

Nonablative lasers were developed as alternatives to ablative laser treatments. This class of lasers produces a milder effect compared with its ablative counterpart. Studies show a quantitative improvement range of 8.9% to 11% in skin laxity 3 months posttreatment.^24,25 Nonablative lasers induce controlled tissue injury in the dermis, which leads to stimulation of dermal remodeling and collagen production.¹¹ Although the effects of nonablative lasers are milder compared with their ablative counterparts, they possess the superior benefit of minimal adverse events. Most studies reported transient erythema posttreatment, but no long-term adverse effects have been noted,^26-31 in part due to preservation of the epidermal layer.

Radiofrequency

Radiofrequency technology was the first method marketed for noninvasive skin tightening. Radiofrequency devices work by generating heat through tissue resistance to an applied alternating electrical current, which leads to collagen contraction and remodeling along with neocollgenesis.³² The major electrode configurations used in these technologies are monopolar, bipolar, and multipolar, which differ by the electric field they produce. Reported side effects include erythema that arose 1 week following completion of treatment and resolved by 6-month follow-up, as well as hypertrophic scarring, transient postinflammatory hyperpigmentation, and pain.^33,34

Monopolar systems were the first among these devices to be developed for use in skin tightening and remain the most extensively studied technology for treatment of skin laxity. Developed in 2001, the Thermage device (Solta Medical, Valent Pharmaceuticals) remains the most extensively studied technology for the treatment of skin laxity.³⁵ In a trial performed by Fitzpatrick et al,³⁶ treatment of skin laxity of the periorbital area with ThermaCool TC (Thermage, Inc) demonstrated an 83.2% improvement in at least 1 point treated and an overall 28.9% improvement of the entire treatment area at 6-month follow-up. Additionally, a survey study of 5700 patients who received monopolar RF skin tightening treatments demonstrated that 26% of patients experienced immediate tightening following treatment, and 54% observed tightening 6 months posttreatment.³⁷

Bipolar and multipolar devices were developed following the success of monopolar devices in the treatment for skin laxity. In a study evaluating multipolar RF for the face and neck, all 11 patients were determined to have improvement of their skin laxity following weekly treatments for 8 weeks.³⁸

Ultrasound

The use of ultrasound for skin tightening was first approved in 2009.³⁹ The primary mechanism of skin tightening is through thermally induced contraction of collagen with subsequent collagen neogenesis achieved through absorption of the vibrational acoustic energy into target tissue.⁴⁰ There are 2 types of ultrasound methods: microfocused and high-intensity focused. Microfocused ultrasound focuses on delivering lower-energy pulses to the deep reticular dermal and subdermal layers that lead to disruption of the underlying architecture of the skin, promoting increases in distensibility, elasticity, and viscoelasticity.⁴¹ To date, microfocused ultrasound is approved for treating skin laxity of the eyebrow and submental area and wrinkles of the décolleté. Currently, there are 2 devices approved by the US Food and Drug Administration for the treatment of skin laxity with ultrasound. These devices are the Ulthera System (Merz Pharmaceuticals) and the Sofwave system (Sofwave Medical Ltd).⁴² Oni et al⁴³ evaluated 93 patients following treatment using Ulthera for skin laxity in the lower face. There was a noticeable improvement of 63.6% at 90 days following treatment. Brobst et al⁴⁴ showed improvement in laxity at 6 months and 1.5 years following last treatment. The most commonly reported posttreatment side effects include transient purpura, transient edema, and transient postinflammatory pigmentation.^42,45 Serious complications are rare and include development of palpable subcutaneous nodules and motor nerve paresis.^42,46

High-intensity focused ultrasound has been more recently introduced as a modality for skin tightening and rejuvenation. This method focuses on applying heat to areas through acoustic energy to areas of the deep dermis, subdermal connective tissue, and fibromuscular layer in targeted microcoagulation zones without effect to the epidermis.⁴⁷ The targeted thermal effects and microcoagulation are believed to cause skin tightening through collagen contraction and remodeling. Future studies are needed to determine the overall benefits in skin laxity to achieve approval by the US Food and Drug Administration for use as a treatment option.

IPL Therapy

Intense pulsed light therapy is different from lasers in that it utilizes a wider variety of wavelengths ranging from approximately 500 to 1200 nm.⁴⁸ The process of skin tightening is achieved through selective photothermolysis in which thermal damage is focused solely on pigmented targets at the cellular or tissue levels in the epidermis and dermis.⁴⁹ Intense pulsed light penetrates the tissues and is selectively absorbed by melanin and hemoglobin, thereby producing photothermal effects. The photothermal effects lead to reversible thermal damage to surrounding collagen and induction contraction of collagen fibers and fiber remodeling.⁵⁰ Clinical studies on the effectiveness on skin tightening have shown incongruent results. Multiple studies have noted improvement in skin elasticity as well as increased deposits of collagen in treated areas. Other studies have shown no improvement of rhytides or wrinkle reduction. The side effects noted were transient pain, swelling, and erythema, along with rare instances of blisters and crusting.^48,51-54 Due to the inhomogeneous results, the use of IPL is largely reserved for treatment of acne, hyperpigmentation, hypertrichosis, and superficial vascular malformations.