Nonablative Facial Skin Tightening

Author: A John Vartanian, MD
Coauthor(s): Steven H Dayan, MD

Introduction

Reduction of rhytides and skin laxity can significantly contribute to improving overall facial appearance. Dermabrasion, chemical peels, and resurfacing lasers (eg, carbon dioxide laser, erbium:yttrium-aluminum-garnet [Er:YAG] laser) are the current mainstays of ablative facial resurfacing. During an ablative facial resurfacing process, the epidermis is denuded to a certain depth by the direct physical, chemical, or thermal injury applied to the skin.
The ablative cutaneous injury induces a healing response, resulting in the deposition of a new skin matrix with improved characteristics. During this so-called healing process, skin rejuvenation occurs by a proliferation of fibroblast activity, the action of inflammatory mediators, and a deposition of new collagen and other dermal matrix proteins.

Despite achieving appreciable clinical results, the adverse effects of ablative resurfacing modalities can result in significant edema and erythema that last for several weeks. The potential for impressive clinical improvements must be balanced against well-described morbidities (eg, protracted edema and erythema), long-term sequelae (eg, pigmentary changes), and potential complications (eg, scarring). As such, the typical prolonged recovery times and the potential problems associated with these ablative modalities may also limit their use in patients who desire a rejuvenation procedure with reduced downtime and a minimal risk profile.

Nonablative Rejuvenation

In contrast to ablative rejuvenation procedures, nonablative laser rejuvenation procedures induce a dermal healing response without notable injury to the epidermis. Improving the appearance of the skin without injury to the epidermis is a hallmark of nonablative skin rejuvenation. The exact mechanisms of nonablative dermal remodeling are still under investigation; however, a subthreshold laser-induced injury to the dermis and/or the dermal vasculature theoretically results in a wound repair response, fibroblast stimulation, and collagen reformation.

The main nonablative laser rejuvenation modalities involve the application of mid-infrared lasers. Certain visible light lasers (VLLs), such as the pulse dye laser or the intense pulse light laser, have been shown to induce dermal remodeling in patients with lighter skin tones. These lasers are discussed for historical purposes in a later section of this article.
An increasing body of evidence suggests that lasers in the mid-infrared range may be the best choice for safe nonablative resurfacing on a wide range of skin types. This article focuses on the following mid-infrared lasers: the 1320-nm neodyminium:yttrium-aluminum-garnet (Nd:YAG) laser (CoolTouch, CoolTouch Corp, Roseville, Calif) and the 1064-nm Nd:YAG laser (Lyra, Laserscope, San Jose, Calif).

Basic Tenets

The ideal nonsurgical rejuvenation method for the aging face is dependent on each patient’s skin type, rejuvenation goals, recovery time priorities, threshold for complications, and esthetic expectations. Influencing these important factors is the physician’s experience and familiarity with a particular rejuvenation modality. An ideal rejuvenation modality induces an improvement in the skin without causing injury to the epidermis.

Nd:YAG Lasers (Mid-Infrared Range Lasers)

Laser energy in the near- and mid-infrared locations on the spectrum is weakly attracted to melanin. When epidermal melanin is bypassed more efficiently, patients with all skin types can be treated with reduced risk. Also, by extending the wavelength of the selected laser to the infrared and mid-infrared areas, deeper energy penetration can be achieved, and laser energy can be delivered to the dermis. The epidermis is bypassed, and the heat that is produced by laser energy is nonselectively deposited in the dermis. Theoretically, heat-induced dermal injury eventually results in the activation of dermal fibroblasts and the induction of a healing response. An inflammatory response within the dermis to the laser-generated heat hypothetically initiates a reaction that leads to collagen remodeling and an improvement in the appearance of facial rhytides.

Early studies with the 1320-nm Nd:YAG laser demonstrated histologic evidence of dermal collagen homogenization, indicating the occurrence of a degree of dermal remodeling. However, the use of the 1320-nm Nd:YAG laser without a skin-cooling device produced discouraging clinical results. Moreover, the clinical risk profile of this modality included pitted scars and hyperpigmentation that occurred at a rate of 30% and 40%, respectively.

Skin-Cooling Techniques Coupled With Nd:YAG Lasers

Coupling the 1320-nm Nd:YAG laser handpiece with a thermal sensor and a cooling cryogen blast allows the surgeon to better control the surface temperature of the skin. The laser is able to induce greater thermal stimulation of dermal fibroblasts within the papillary dermis and the mid-reticular dermis, while cooling the epidermis and protecting it from direct thermal injury.

Cooling the skin and delivering the laser pulse can be coordinated in numerous theoretical ways, that is, skin cooling prior, during, or immediately after laser pulse delivery to optimize treatment. In this manner, the temperature of the dermis can increase to 60-70°C, while the temperature of the epidermal surface can be safely maintained at 40-48°C. As observed clinically, effective cooling of the skin can minimize the risks of scarring and hyperpigmentation. With strict control of the surface temperature, the risk of pigmentation changes seems to be averted, even in Fitzpatrick skin types IV and V.
Kelly et al were among the first to publish their experience in treating facial rhytides with the 1320-nm Nd:YAG laser coupled with a cryogen spray.⁵ This initial study demonstrated statistically significant improvement at 3-month follow-up; however, at 6-month follow-up, only patients with severe rhytides retained their previously observed improvements.

Pham applied the 1320-nm Nd:YAG laser with a thermal sensor and a cryogen cooling spray to the rejuvenation of darker skin types (Fitzpatrick skin types III, IV, and V) in Asian patients. Pham noted an improvement in periorbital rhytides at 6 months in all (of 4) patients who had undergone serial (multiple) treatments. He also noted no complications or adverse effects, except for transient erythema. Clinical observation did not reveal any cases of hyperpigmentation. Histologic evaluation of biopsy specimens taken 2 weeks after treatment did not show any increase in melanin content.

Pham’s experience highlighted the need for a multiple treatment regimen. Of those who were treated once, only 2 out of 8 (25%) patients demonstrated an improvement at 6-month follow-up; even the improvements observed in these patients were not found to be statistically significant.

The 1064-nm Nd:YAG Laser Coupled With Skin-cooling Device

The extended pulse 1064-nm Nd:YAG laser is a safe and proven technology that has been effectively used in laser epilation in patients of all skin types and colors. Similar to the 1320-nm Nd:YAG laser, the 1064-nm wavelength deposits nonselective heat into the dermis with a minimal affinity for melanin. The advantages of this modality for wrinkle reduction include the technical ease of performing the procedure, minimal to no patient discomfort, and the ability to treat all skin types with little risk of epidermal injury.
Goldberg’s side-by-side comparisons of perioral rhytides treated with an IPL source and the 1064-nm Nd:YAG laser revealed similar improvement in rhytid reduction, with the Nd:YAG laser being better tolerated by patients. Additionally, although not statistically significant, patients who were treated with the Nd:YAG laser subjectively described an improvement in rhytid reduction that lasted up to 24 weeks following their final treatment.
In a 2003 study by Dayan et al involving 51 patients over a 4-month period, treatment with the 1064-nm Nd:YAG laser coupled to a cooling handpiece produced improvement in several skin quality parameters. Thirty-four patients completed a minimum of 7 treatments, which were spaced in 1- to 4-week intervals, with the favored interval being every 2 weeks.

Treatments were initiated using a 10-mm handpiece at a setting of 22 J/cm², a 50-millisecond pulse width, and a frequency of 2 pulses per second. These settings were chosen based on the following theoretical reasons: the energy was below the threshold level for melanin follicular damage, the pulse width was extended beyond the thermal relaxation time of skin melanin (3-10 milliseconds), and the overall energy would produce enough heat for a subthreshold injury to the surrounding dermis.

Blinded physician analysis based on pretreatment and posttreatment photographs demonstrated subtle (and statistically significant) decreases in coarse wrinkles, skin laxity, and overall improvement scores. Patient self-assigned subjective scores declined after 6 treatments in relation to coarse wrinkles, skin laxity, and overall improvement. In this study, no complications were encountered, the anesthetic needs of the patients were minimal to nonexistent, and the laser operators described a shallow learning curve. While improvements in photodamaged skin were subtle and gradual, the laser was well tolerated by patients of all skin types. Anesthesia requirements for the patients were minimal, and patients did not require any pharmacologic intervention.

Although not part of this study, the authors reported no blister formation, prolonged erythema, scarring or dyspigmentation (regardless of skin type), or any major adverse reactions in over 500 facial treatments using the 1064-nm Nd:YAG laser. The conclusion of this study was that nonablative resurfacing techniques using the 1064-nm Nd:YAG laser coupled with a cooling handpiece were well suited for patients who request facial rejuvenating treatments with minimal downtime.

Conclusion

Nonablative resurfacing techniques are well suited for patients who request rejuvenating treatments of the aging face. Regardless of the laser type, improvements in fine lines, wrinkles, and photodamaged skin are subtle and gradual. While many different lasers and nonlaser light sources are being investigated in an attempt to identify the favored modality, the extended pulse Nd:YAG lasers provide particular benefits. However, both the 1320-nm Nd:YAG laser and the 1064-nm Nd:YAG laser when coupled with a skin-cooling device are unique in that they are well tolerated by patients of all skin types. Furthermore, at this time, these treatments have been found to be safe.

Nonablative laser treatments, while desirable, have yet to replace proven resurfacing techniques or standard surgical procedures for facial rejuvenation. Patients with moderate-to-severe rhytidosis still need surgical or ablative skin-tightening procedures for appreciable facial rejuvenation. Further studies and histologic evaluations are also necessary to determine the ideal settings to achieve long-term benefits and to minimize possible sequelae of these nonablative modalities. Moreover, the lack of long-term follow-up hinders the ability to evaluate the long-term safety record of these new treatment modalities. Nevertheless, nonablative rejuvenation may provide an attractive alternative for the person who is unable to afford the downtime of more aggressive procedures and is dissatisfied with the minimal gains achieved from superficial peels and microdermabrasion.