In the past decade, laser- and light-based devices have become popular methods for treating a variety of cosmetic concerns. From photofacials to photoepilation, light-based chromophore-targeting technology has allowed clinicians to tackle pigmentation, skin texture, and hair concerns, just to name a few.
The professional treatment of these conditions using lasers and light-based devices has been well established and proven safe and effective in the medical setting, via the use of large and expensive machines that were designed to be operated by aesthetic professionals.
Recently, several companies have capitalized on the experience gained in medical spas and clinics in order to offer over-the-counter (OTC) light-based systems for personal cosmetic use. These products are marketed and sold directly to consumers without a prescription or a need to visit an aesthetic specialist.
The FDA clearance data and emerging clinical data on these new devices opens up a tremendous possibility of dramatically boosting the consumer skin care market.
Clients who frequent cosmetic practices will likely seek information on these new devices from their treating physicians. These consumers will require additional information on safety, efficacy, and adjuvant procedures.
For the most part, the new devices are being used for hair removal, treatment of acne, and rejuvenation of aging skin.
In the arena of hair removal, areas typically treated include the face, neck, axillae, back, and extremities. Laser procedures target melanin in the hair bulb. When melanin absorbs laser energy of the appropriate wavelength, the absorbed energy is converted to heat that selectively destroys the hair bulb. The presence of melanin in the epidermis limits the efficacy of laser-based systems.
Hair has also been successfully removed with intense pulsed light (IPL) devices, which, though effective, are associated with some adverse effects such as postinflammatory pigmentation, pain, discomfort, and crusting.
The use of combination radiofrequency and IPL has also been evaluated. All methods remove hair by a thermal mechanism and selective photothermolysis.
There are three main hair-removal devices:
- No!No! (Radiancy Inc, Orangeburg, NY) employs a patented thermal heating element called Thermicon. This technology slows down the activity of the bulb cells in the hair follicle.
- The Silk’n (Home Skinovations, Yokneam, Israel) utilizes a broad-spectrum light source similar to an IPL that the company is calling HPL (home pulsed light). The company also claims the product has an acoustic energy element.
- The Tria (Tria Beauty, Pleasanton, Calif) uses diode laser technology, featuring a patented form called Diffuse Radiance Technology that takes coherent light and scatters it.
All three employ lower energies than those available in the medical setting. However, when used for longer periods of time (up to 8 to 12 weeks), in clinically proven studies these products have produced up to 50% to 60% long-term hair removal.
The results are almost comparable to what aesthetic specialists are able to achieve in office settings. The efficacy and safety of these devices has been documented in several recent scientific studies in published literature.
The No!No! handheld self-treatment device consists of an AC/DC power converter and a handpiece that houses control electronics, contact rollers, and a replaceable thermal filament. A green light-emitting diode (LED) indicates that the rollers and filament are correctly positioned and that the device is moving at the correct pace. A red LED indicates a problem with the filament.
During treatment, the hair shaft is heated and singes slightly, leaving residual hair to be brushed away. When motion stops or is reduced below threshold, the filament retracts from the skin and instantly cools.
In a controlled clinical study of the No!No! by Spencer,1 conducted on 20 adult volunteers following 1 week of treatments, the average hair-count reduction from baseline was 27%. Hair reduction increased weekly to a level close to 48% at week 12. These immediate post-treatment clearance rates, observed on leg hair, were maintained within 90.6% at 12 weeks after the final treatment. These clearance rates are higher than the clearance rate obtained with the long-pulsed alexandrite laser in the study by Nanni and Alster.2
For at-home acne treatment, the Zeno and Zeno Mini (Zeno Corp, Houston) and ThermaClear devices employ heat elements.
Zeno’s treatment regimen, for example, is two to three treatment cycles of a few minutes each over 12 to 24 hours. Zeno’s internal microprocessors maintain the temperature within a fixed range, and an integral digital timer controls the treatment time. In an FDA-reviewed, controlled clinical trial, 90% of blemishes treated with Zeno disappeared or faded within 24 hours, according to the company.
|Tria Laser 100|
The ThermaClear acne treatment device uses the company’s trademarked Thermal Pulse Technology to clear pimples safely. The FDA-approved handheld medical device for the treatment of mild-to-moderate inflammatory acne uses a very short controlled burst of heat to treat individual acne lesions, neutralizing the underlying bacteria.
Under development is the No!No! skin-clearing device, which uses broad-spectrum light heat pulsing technology. Another product, the Clarisonic Skin Care Brush (Pacific Bioscience Laboratories Inc, Bellevue, Wash), has been on the market for some time.
Acne, the chronic inflammatory disorder of the pilosebaceous unit, is associated with Propiobibacterium acnes (P. acnes) and is generally treated with OTC topical cleansers, astringents, benzoyl peroxide preparations, and prescription topical and systemic antibiotics.
It has been increasingly documented that P. acnes is developing increased resistance to antibiotic treatments, making this modality less effective and desirable. Although P. acnes is quite sensitive to heat treatments, the exact mechanism is unknown. It is well known that the expression of various heat-shock proteins (HSP) increases when cells are exposed to elevated temperatures or other stress. This increased expression of HSP may be the triggering molecular change that is associated with bacterial death after heat treatment is applied.
In a double-blind placebo-controlled trial of the Zeno platform conducted by Bruce et al3, results suggest that the application of a low level of sustained heat is potentially beneficial to individual acne lesions.
The Zeno device delivers a thermal dose of 121°F (49.4°C) for 2.5 minutes over a surface area of roughly 0.099 in2. The results demonstrated that the active treatment significantly shortened both the median time to improvement (12.8 versus 35.6 hours, p < 0.0001), as well as the median time to resolution (89.7 versus 140.1 hours, p = 0.0020), as reported by blinded physicians.
See also “Energy-Based Technologies” in the March 2007 issue of PSP.
No adverse events were reported, leading to the conclusion that this treatment modality is simple, nontoxic, and effective against individual acne lesions and represents an additional tool for patients who suffer from mild to moderate outbreaks of acne.
Antiaging rejuvenation technologies are recently just entering the market. Studies are ongoing using red-light LED sources. As recently as June 2009, Palomar Medical Technologies Inc received OTC clearance from the FDA for a new, patented, home-use laser device for the treatment of periorbital wrinkles. The device was developed by Palomar and completed together with Johnson and Johnson Consumer Companies Inc.
In addition, Cynosure Inc (Westford, Mass) announced in June that it teamed up with Unilever to develop cosmetic lasers in a series of home-use devices aimed at combating wrinkles and other signs of aging.
As you can see, these are exciting developments for consumers desiring to safely treat themselves at home with technologies that deliver near comparable professional results for hair removal, acne treatment, and photorejuvenation. The key difference is that at-home technology requires longer treatment times and duration of treatment.
Neil Sadick, MD, FAAD, FAACS, FACP, FACPh, is a renowned dermatologist and researcher who holds board certifications in dermatology, cosmetic surgery, internal medicine, and hair transplantation. He is clinical professor of dermatology at Weill Cornell Medical College, president of the Cosmetic Surgery Foundation, and member of the board of examiners for the International Society of Hair Restoration Surgery, among other titles. He can be reached at (212) 772-7242.
- Spencer JM. Clinical evaluation of a handheld self-treatment device for hair removal. J Drugs Dermatol. 2007;6(8):788-792.
- Nanni CA, Alster TS. Long-pulsed alexandrite laser-assisted hair removal at 5, 10, and 20 millisecond pulse durations. Lasers Surg Med. 1999;24(5):332-337.
- Bruce S, Conrad C, Peterson RD, et al. Significant efficacy and safety of low level intermittent heat in patients with mild to moderate acne. Available at: www.myzenoeurope.com/doc/zenowhite.pdf. Accessed July 16, 2009.