BBI Contributing Editor
DALLAS, Texas The American Society for Laser Medicine and Surgery (ASLMS; Wausau, Wisconsin) drew a record number of attendees from around the globe for its 24th annual meeting here in April. More than 1,500 people from academia, private clinical practice, government agencies, national laboratories and industry attended the multidisciplinary conference to examine the newest applications of lasers, light sources and energy devices in medicine and aesthetic surgery.
In the high-tech aesthetic treatment realm, speakers evaluated a wide spectrum of energy sources featuring laser devices, pulsed light systems, radiofrequency waves and ionized plasma for the treatment of virtually every cosmetic condition from acne, hair growth, lax skin tissue and wrinkles to tattoos, pigmented and vascular lesions and scarring. Coming full circle, presenters argued the pros and cons of ablative resurfacing using a variety of laser wavelengths and the pluses and minuses of non-ablative techniques for photorejuvenation, including LED photomodulation, cosmetic photodynamic therapy and combination treatment modalities.
The introduction of a new treatment category in skin rejuvenation, which Whitney Tope, MD, associate clinical professor of dermatology at the University of California, San Francisco, characterized as "delayed ablative resurfacing," created considerable buzz at the scientific sessions. Headliners in the new face-saving category included fractional resurfacing, plasmakinetic skin regeneration and electro-optical synergy. Established leaders like Candela (Wayland, Massachusetts), CoolTouch (Roseville, California), Lumenis (Yokneam, Israel) and Thermage (Hayward, California) leveraged significant podium power to reinforce the scientific validity and clinical versatility of their respective non-invasive aesthetic technologies.
A packed crowd was on hand for the "Emerging Technologies in Lasers in Plastic Surgery and Dermatology" workshop, which focused on light based therapies for acne and acne scarring; novel approaches to skin rejuvenation; and evolving uses of photodynamic therapy. James Leyden, MD, professor of dermatology at the University of Pennsylvania Hospital (Philadelphia, Pennsylvania), opened the session with his perspective on the therapeutic value of lights, lasers and radiofrequency for the treatment of acne. He reviewed two widely accepted mechanisms of action: 1) interaction with P. acnes copoporphyrin and the reduction of the number of organisms; and 2) interaction with various chromaphores in skin or topically applied photosensitizers that lead to sebaceous gland destruction. Leyden maintained that treatments directed against P. acnes alone "will require prolonged laser treatments to keep P. acnes levels reduced, similar to the need for prolonged courses of antibiotics." He added that "reports of prolonged remissions after a few treatments or, as recently reported, after one treatment, are unlikely to be reproducible."
Instead, Leyden proposed that treatments which target the sebaceous glands while sparing injury to the epidermis are more promising in terms of being capable of inducing longer-term remissions. He cited a comprehensive Journal of Investigative Dermatology study of PDT with ALA and red light which clearly demonstrated destruction of sebaceous glands and prolonged remission. However, he noted that "the epidermal reactions were such that this treatment is not practical. Still, it does show the possibility of the approach."
According to Leyden, less-rigorous studies using 1320 nm, 1450 nm or 1540 nm lasers to affect the sebaceous glands have shown greater potential for clinical benefit, particularly on the back. "With this approach, we can expect to see prolonged periods free of disease that is, periods of acne clearing while the stem cells are repopulating. The challenge is that treatments on the face can be too painful for many patients," he said. Looking at the use of radiofrequency, Leyden said he believes "this technology is still in its infancy. While it offers promise as an effective therapy for acne, more study is needed."
Overall, Leyden maintains that there is evidence to say there is promise for laser technologies in the treatment of acne. However, he would like to see more systematic studies conducted such as those done for the drug approval process. He said: "We need multi-center trials in several hundred patients, with follow up and careful assessment of side effects and complications. Patients should have 20 or more inflamed lesions with lesion counts by trained observers and photo documentation available on all patients."
During a discussion of acne treatment protocols and parameters, Roy Geronemus, MD, director of the Laser & Skin Surgery Center of New York (New York), said that he uses a variety of laser devices and light sources depending on the type of acne and the severity of the condition. While he typically starts patients on a topical regimen, he finds that ClearLight works well for less-complex acne like papularpostular acne. He often uses the Smoothbeam 1450 diode laser for more resistant acne and applies a topical anesthetic cream to minimize patient discomfort. He said he likes the CoolTouch 1320 Nd:YAG with its dynamic cooling for acne scarring, along with LED photomodulation. "For patients who don't qualify for or are resistant to topicals or antibiotics, and for those patients who simply don't want conventional treatment, lasers and light systems are a safe and effective therapeutic option," Geronemus said.
In the category of novel approaches to skin rejuvenation, Brian Biesman, MD, a cosmetic and reconstructive ophthalmologist in Nashville, Tennessee. presented his insights on "Radiofrequency (RF) Devices: Monopolar vs Bipolar vs Radiofrequency plus Laser." An accomplished surgeon, Biesman noted that monopolar RF devices have been used for many years in a variety of surgical applications to perform hemostatic dissections. These established monopolar machines use a conductive coupling delivery system that concentrates the energy at the periphery of the electrode. However, this accumulation of heat energy poses a problem for noninvasive skin rejuvenation. To overcome this problem, Thermage developed a monopolar RF delivery system that includes a proprietary capacitive coupling device which permits uniform energy distribution across the entire electrode surface with subsequent volumetric tissue heating. Biesman observed: "In my clinical experience, the greatest benefits of the ThermaCool device are achieved when treating the lower face and neck."
Turning to the family of devices manufactured by Syneron (Yokneam, Israel), Biesman noted that the company has applied RF technology to skin rejuvenation in an entirely new manner. Rather than using RF energy alone, Syneron scientists have coupled RF energy with light energy, referred to as ELOS technology, an acronym for electro-optical synergy. Unlike the Thermage system, the Syneron product line uses a bipolar RF delivery system. Biesman explained that the underlying concept of this technology is that RF energy is used to raise the tissue temperature, thus decreasing the amount of additional tissue heating needed to achieve the clinical objective. Depending on the intended results and the device in use, the timing of RF current relative to light energy and the pulse parameters will vary. Epidermal cooling is provided via a cooling device built into the handpiece.
Syneron developed the Polaris device that combines bipolar RF energy delivery with laser light, using a 900 nm diode laser coupled with a higher powered RF generator. Like the Aurora, it employs different modules, one for treating vascular lesions and the other for wrinkle reduction. These modules differ in the application tip design, sequence of firing and pulse profile. Although Biesman said he hasn't had hands-on experience with the Polaris, he reported that the system has been internationally used with good success for vascular lesions and tissue tightening. In contrast to the Thermage system, Biesman said the Polaris "is generally used to provide a series of treatments to accomplish desired endpoints. Further, there are currently no case studies of using ELOS technology in areas other than the face and neck."
He said it is clear that RF has an"important role" to play in a wide range of clinical applications. However, "we still have much to learn regarding which energy source plays the greater role, how bipolar devices stack up against unipolar devices, optimal treatment parameters, patient selection, treatment protocols and ideal indications."
Light-emitting diode (LED) photomodulation represents another evolving approach to global skin fitness by improving skin tone, texture, roughness and fine lines, as well as reducing redness and pigmentary discoloration. Geronemus presented the basic principles of LED photomodulation for skin rejuvenation; namely, the use of a non-thermal, low-level light source to modulate cell response such that collagen production is increased, and production of MMP-9 collagenase is decreased.
He reported on a multi-center study led by Robert Weiss, MD, of Baltimore, Maryland, that involved collecting and measuring serial skin biopsy from subjects at various time points; in vivo immunochemistry for structural proteins such as collagen and degradatory enzymes, along with cell signaling markers; and in vitro human fibroblast tissue analysis. Data from the 12-month clinical trial of 60 patients showed that global improvement progressed on average for four months and persisted for 12 months. Results showed that there was a favorable increase in extracellular matrix proteins such as Collagen I, and a decrease in negative enzymes such as collagenase/MMP-1 and other MMPs. Geronemus also noted that there was a remarkably close correlation between the in vivo and in vitro data. "In particular, patterns of cell signaling and gene expression were directly associated with clinical observations of the photoaged facial skin on patient subjects."
Based on the study results, he said the research team concluded that "non-thermal LED phototherapy can modulate the activity of certain genes in human fibroblasts, resulting in a net increase in collagen formation and extracellular matrix proteins that are responsible for improved skin tone and texture, reduced pore size, and fewer lines and wrinkles." Geronemus added that the clinical effect of such modulation "is the transformation in the appearance of damaged facial skin to a more youthful phenotype. Moreover, we now have strong evidence that the skin rejuvenation effects of non-thermal LED treatment have a molecular basis that appears to differ from the mechanism of action of thermal nonablative therapies."
Geronemus then shared findings of the recent solar simulator study conducted by David McDaniel, MD, using the GentleWaves LED device on UVA-exposed tissue. The in vitro study measured gene expression of Collagen I/MMP-1 at four hours and 24 hours post exposure to UVAI 340-400nm solar simulator with 360WG filter and 590 LED photomodulation. "Results suggest that following UVA exposure, GentleWaves LED treatment minimizes the fibroblast damage," he said.
According to Geronemus, the solar simulator study also lends support to the wound-healing capabilities of LED photomodulation. "We find that use of LED therapy after laser resurfacing facilitates the healing process." He offered a glimpse into the future potential of GentleWaves for the treatment of hair loss: "Preliminary investigations using GentleWaves LED to stimulate hair growth are under way and look to be the next frontier in anti-aging medicine."
Dieter Manstein, MD, of the Wellman Laboratories of Massachusetts General Hospital (Boston, Massachusetts), presented the scientific theory of fractional photothermolysis, which involves a fiberoptic laser microbeam device, dubbed the Fraxel SR Laser, from Reliant Technologies (Palo Alto, California), to selectively treat only a very small fraction of skin at a time. "The challenge was to determine the optimal thermal damage pattern for skin remodeling that will achieve effective clinical results with minimal side effects and downtime," Manstein said. "Instead of ablating and damaging an entire layer of skin, fractional resurfacing creates thousands of laser-induced microscopically small thermal damage zones. Accordingly, each laser treatment resurfaces approximately 17% to 20% of the skin."
Manstein likened the novel fractional laser technology to digital photography and popular image-editing software such as PhotoShop or PaintShopPro, with digital images composed of thousands of colored dots or pixels that are invisible to the naked eye and can only be detected under magnification. The factional laser works in a similar way by using a laserbeam to heat tiny columns of tissue at a rate of 500 per centimenter and lay down a pattern of small, microscopic spots separated by areas of unaffected, healthy tissue. The diameter of each laser spot or micro thermal zone (MTZ) is about 1/8 the width of a human hair.
"The idea is to produce microscopic sites of heating and space these 'volumetric columns' some distance apart," Manstein said. "The surrounding islands of spared epidermal tissue contain viable cells that promote rapid re-epitheliazation via formation and exfoliation of micro epidermal necrotic debris (MENDs)." He said fractional resurfacing will offer patients the benefits of rapid healing, a well-controlled stimulus for regeneration of fresh skin, reduced risk of side effects and little or no risk of infection compared with traditional resurfacing and chemical peels.