Using layered effects — changing parameters and going back over some areas such as scars — brings a little more efficacy to those areas.
For vascular lesions, the Cynergy (Cynosure) combination 595 and 1,064 nm laser and the modified Vbeam (Candela) offer technical advantages designed to enhance treatments, says Brian D. Zelickson, M.D., associate professor in the department of dermatology, University of Minnesota, Minneapolis.
The Cynergy laser is based on prior research combining lasers operating at both 532 and 1,064 nm (Barton JK et al. Photochem Photobiol. 2001 Jun;73(6):642-650), (Black JF, Wade N, Barton JK. Lasers Surg Med. 2005 Feb;36(2):155-165), he says. Such a combination allows one to hit the vascular target with the lower-wavelength laser and convert hemoglobin to methemoglobin, he explains.
Dr. Zelickson says that this conversion changes the lesion's optical absorption characteristics to make it more susceptible to being absorbed by an infrared laser source. Within several tenths of a millisecond after the first pulse, the lesion is hit by a second laser pulse at 1,064 nm. The advantage is that, potentially, lower energies with each of these wavelengths could be used, and enhance the treatment effect while also producing fewer side effects.
For skin resurfacing applications, new options include the Fraxel (Reliant Technologies), which Dr. Zelickson's practice uses to treat photodamage and acne scars.
Pushing the envelope
"We're pushing the energy levels more now," he says. "Whereas before, total energy to treat a full face was anywhere from 4 kJ to 6 kJ, we're now getting more aggressive, using 6 kJ to 8 kJ, and sometimes even a little higher. So we're putting more energy per treatment into the face and getting better results."
At the same time, his practice is achieving more even treatments and greater efficacy by adjusting treatment technique.
"One must pay careful attention to technique, making sure that the handpiece remains perpendicular to the surface being treated, that one applies dye evenly and that one moves the handpiece with an even, steady motion," Dr. Zelickson says.
Using layered effects - changing parameters and going back over some areas such as scars - brings a little more efficacy to those areas, he adds.
Conversely, he says Rhytec's Portrait PSR (plasma skin regeneration) system uses nitrogen plasma and radiofrequency energy to create a thermal injury.
"It's basically a coagulative resurfacing device," Dr. Zelickson explains. It treats the full surface of the skin, but it doesn't ablate tissue, which remains on top to facilitate faster healing than ablative systems including CO2 or erbium lasers would allow.
In an unpublished study involving 12 patients given low-energy treatments with this device, he says his practice has shown that patients experienced mild redness for about two days post-treatment. After performing a series of three treatments (1 J/cm2) at weekly intervals, Dr. Zelickson notes that the results were modest, and more energy will be needed to get better results.