Refining Light Therapy
An array of devices gives physicians many choices. But setting realistic expectations for patients is crucial.
The world of aesthetic light therapy is a blend of ablative and nonablative devices. As the demand for laser services grows, manufacturers continue to refine the technology so physicians can produce accurate, reliable results.
When it comes to facial rejuvenation, no one piece of equipment can do it all. That's why we have an extensive array of choices. Let's look at these choices, starting with the forerunners in light and laser technology.
The Ablative Era
In the mid-'90s, ablative CO2 facial resurfacing took the worldwide aesthetic market by storm. This CO2 device gave physicians the chance to remove old, damaged skin and replace it with new healthy skin-a process equated to the well-established Phenol chemical peel.
As with many new procedures, something was seen in the process not expected and initially not understood: a change in collagen presence and quality. Not only were physicians tightening tissue through heat deposition, but they also were generating and remodeling collagen. It was an exciting discovery.
But all of this came at a cost: exten-ded downtimes for healing and unpredictable changes in skin tone and color. Certain areas couldn't be treated due to decreased skin thickness, leaving the patient with lines of demarcation at the untreated margins.
Despite these problems, the CO2 was a good tool. It was the best device we had at the time for total skin rejuvenation. Physicians accepted this as fact and worked within the device's limitations.
The Nonablative Era
During that same time period, intense pulsed light (IPL) came on the scene as a potential answer for hair reduction. It was soon discovered-as with many procedures and devices-that skin texture and tone also improved. Redness and pigment decreased as well, another beneficial side effect of IPLs. The nonablative IPLs didn't share the downtime or hypopigmentation issues as the ablative procedures. Yet, they produced some of the similar CO2 remodeling changes, but on a smaller scale. IPLs allowed us to affect the quality and structure of skin without ablative removal or negative alteration.
It was theorized that a nonablative procedure caused a wound healing response in tissue without removing a single cell or producing a single wound. A simple, nonlight example might be slapping the left side of the face daily. Eventually, the skin would produce more padding or collagen on that side to protect the body from the insult that's occurring regularly. Physicians and researchers discovered they could stimulate the same response by producing an insult on the skin with light at a low, nondamaging level.
As with any tool, we tend to push the technology to the ultimate response level. In doing this with IPL, we started to notice some of the same previously mentioned pigmentary complications associated with the CO2.
We then ventured outside the visible spectrum and used mid-infrared lasers in the 1320 nm to 1540 nm range. These devices would seek water as the source of stimulation in tissue. This would allow us to bypass the competing and complicating melanin and blood on the way down through the epidermis to affect the dermis for collagen stimulation.
Another great step in our evolution was cooling of the epidermis. This cooling allowed us to push more energy deeper by protecting the dermal-epidermal junction where three of four potential complications occur. Physicians, therefore, can avoid hypopigmentation, hyperpigmentation and blistering, while achieving the maximum effect.
Almost all wavelengths had been successfully tried over the next several years and the degree of improvement has varied. Just like slapping the face with different force levels, most wavelengths and modalities create some effect, and some demonstrate better and more predictable changes.
One mistake during this nonablative introduction was the expectation conveyed to patients. Some were quick to announce that nonablative devices produced the same results as the ablative technology, but without the complications. This statement is false, and many physicians have since sworn off light-based procedures as a result of over-promising and under-delivering.
To date, clinical following indicates that measurable but less remarkable changes occur in tissue with nonablative devices. We cannot predict, however, the level of improvement. This especially applies to Type II nonablative procedures and techniques.
As the first of the "nonablative" procedures went to the FDA for review, the government agency classified these devices into two distinct types. Type I improved visible skin anomalies, such as age spots and small vessels. Type II focused on improving and restoring collagen in tissue.
The key in choosing between ablative and nonablative devices is to identify the different intensities and aspects of skin rejuvenation and remodeling. They are different, not only in downtime and complication, but also in their real results. A certain population wants maximum results and should be given the option of an ablative procedure, fully understanding the potential side effects and downtime associated with it.
If this is not acceptable to them, the nonablative procedure may better suit their needs. If they go the nonablative route, a series of treatments will be required, and the results will likely never reach those of an ablative procedure. Furthermore, nonablative Type II procedures take 90 to 180 days for patients to see the full development of aesthetic changes. In this quick reward world, some patients will not accept or tolerate slow and subtle change for their aesthetic dollar.
Given the limitations of ablative and nonablative technology, manufacturers offered a solution in the early 2000s. The Erbium:YAG (2940 nm) microablation emerged, allowing us to ablate tissue in the 10 m to 100 m range without the damaging heat side effects associated with the earlier CO2. Now rather than the "all or none" changes with the CO2, physicians could tailor ablative change, just as they can with different levels of chemical peels.
This technology was first explored at the University of Texas Southwestern Medical Center at Dallas in January 2000. Controlled and limited erbium energies virtually eliminated the heat deposition in tissue and became a great tool for contouring the epidermis while still creating a minimal level of wound healing response. This accomplished several things: improved textures, increased collagen production and shortened downtimes. These devices still didn't produce results as dramatic as the CO2, but they eliminated the side effects associated with it.
Some CO2 manufacturers have seen the benefits of the erbium's quick and controlled effect and have adjusted their devices accordingly. By featuring versions with shorter pulses, manufacturers could offer the same benefits of erbium simply by eliminating the heat associated with the earlier devices.
Ablative and Nonablative Synergy
Since the introduction of microablation, manufacturers have explored combinations of microablation and nonablative procedures with synergistic effects. With these devices, the surface and core of the skin are remodeled in combination. By selecting the procedures and combinations, patients can determine the downtime and improvement they want.
Now, we're experiencing the newest philosophy in ablative and nonablative procedures: the fractional laser procedure. New devices place laser spots that necrose or ablate 100 m to 300 m of tissue, leaving a zone of equal size beneath for maximum wound healing response. By description, the procedure is neither ablative nor nonablative. It doesn't remove layers of tissue, but creates "ablation-like" micro-thermal zones while the majority of epidermis stays intact.
The goal is to leave a high percentage of the tissue intact for increased wound healing time with decreased downtime, while still achieving the effects of a traditional resurfacing procedure. This is the first of a new generation of devices that will combine some ablative and nonablative outcomes, possibly in a single procedure or series of procedures.
Several levels of skin rejuvenation are available to our patients. Before any of these procedures are performed, patients should be on a good skin care program. This will ensure they have healthy skin to repair the insult of the procedure.
If your patients want to roll back the clock a few years with no downtime, nonablative might be the answer. If they're looking to remove damage in the form of pigment and redness while decreasing skin laxity and thickness, a combination of IPL and nonablative will work well with minimal downtime. Fine wrinkles and uneven textures can be addressed with micro-peels.
Deep wrinkles, sun damage and acne scars are best addressed with full-face, full-depth resurfacing, such as CO2 or aggressive erbium. Any combination of the above is possible, but the key is setting realistic expectations with the patient.
John E. Hoopman, CMLSO, is the laser safety officer for the University of Texas Southwestern Medical Center, Dallas, and allied hospitals. He has more than eight years' experience with lasers in research, surgical and clinical applications. He manages the surgical, clinical and technical aspects of more than 180 lasers on the Dallas campus. Hoopman is a board member of the ANSI Z136 laser safety committee, vice chair of ANSI Z136.3 and a consultant to the Texas State Board of Medical Examiners and the Texas Bureau of Radiation Control concerning laser safety. He can be reached at (214) 648-2416 or firstname.lastname@example.org.