28 Wrinkle Reduction with Nonablative Lasers

Nonablative laser treatments for wrinkle reduction (where the term lasers * refers to both lasers and intense pulsed light devices) are aimed at heating the dermis to cause mild injury, while leaving the epidermis intact. A reparative healing process ensues after treatment with collagen shrinkage and synthesis of new collagen and extracellular matrix, referred to as dermal collagen remodeling.^1,² Dermal thickness is increased and the skin is smoothed, resulting in clinical reduction of wrinkles. In addition to wrinkle reduction, collagen remodeling effects with nonablative lasers can also result in reduction of depression scars, pore size, and rough skin texture.

Nonablative lasers are most appropriate for treatment of mild to moderate wrinkles (also called rhytids). Relative to ablative technologies, wrinkle reduction effects are slower and more subtle with nonablative technologies. However, these treatments have the advantage of requiring little to no recovery time, they have lower risks of complications, and are easily incorporated into patients’ daily lives. Common terms used for nonablative wrinkle reduction include nonablative skin rejuvenation, noninvasive resurfacing, and skin toning.

Certain nonablative laser technologies primarily target skin laxity and skin folds. Reduction of skin laxity and folds is commonly known as skin tightening; however, the term used by the Food and Drug Administration (FDA) is soft tissue coagulation, which essentially means thermal injury to the skin. Providers may want to consider using terms such as reduction of skin laxity or crepiness (defined as a crepey or crinkly appearance to the skin) rather than skin tightening, because for some patients, skin tightening may imply surgical-like results with dramatic tissue lifting.

Rejuvenation of photoaged skin typically requires reduction of wrinkles and rough texture in combination with treatment of dyschromia (such as solar lentigines and mottled hyperpigmentation) and vascular ectasias (such as telangiectasias and facial erythema). Nonablative wrinkle reduction with lasers is an important component of aesthetic care and can be readily combined with other minimally invasive aesthetic procedures into office practice to achieve global skin rejuvenation.

Laser Principles and Devices Currently Available

The mechanism by which most nonablative lasers effect collagen remodeling and wrinkle reduction is through focal thermal injury to the dermis while avoiding epidermal injury. Thermal injury can be induced through energy absorption in the skin by melanin, oxyhemoglobin, and/or water chromophores utilizing the principle of selective photothermolysis (see Chapter 19, Aesthetic Principles and Consultation).³ Other methods of inducing thermal injury include using radio-frequency energy, where tissue resistance to applied current heats the dermis. Some technologies utilize fractional methods of delivery that enhance the depth of laser penetration into the skin. Nonablative wrinkle reduction technologies can be broadly classified according to their clinical effects of wrinkle reduction or improvement in skin laxity, and this may be further refined based on the mechanism of action of the technology (see Table 28-1).

TABLE 28-1 Classification of Nonablative Lasers and Light Devices for Wrinkle Reduction

Wrinkle Reduction

Many of the lasers used for nonablative wrinkle reduction target the water chromophore in tissue, including infrared (IR) wavelengths of 1320, 1440, 1450, 1540, and 1550 nm (1064 nm is also an IR wavelength but has less affinity for water). Figure 28-1 shows these wavelengths superimposed on the water absorption curve. By heating water, thermal energy is conducted to the dermal tissue, which stimulates the collagen remodeling process. All of these wavelengths have demonstrated clinical improvements in wrinkles.⁴^–⁷

FIGURE 28-1 Water absorption spectrum and common nonablative wrinkle reduction lasers.

Some of the infrared lasers employ a fractional method of delivery (see Table 28-1), of which 1550 nm has the most data.⁸ Fractional lasers treat a portion or “fraction” of the skin by delivering laser energy in microscopic columns, called microthermal zones. Figure 19-10 in Chapter 19, Aesthetic Principles and Consultation, shows the pattern in the skin made by fractional laser devices. The untreated tissue between microthermal zones serves as a regenerative reservoir, which facilitates rapid wound healing.⁹ This type of treatment is termed nonablative fractional resurfacing. In addition to the collagen remodeling effects of wrinkle and scar reduction, fractional resurfacing with 1550 nm has also shown promise with reduction of dyschromic conditions such as melasma and poikiloderma of Civatte.¹⁰^–¹²

Lasers that target oxyhemoglobin, melanin, and to a lesser degree water, such as 532 nm pulsed dye lasers (585 and 595 nm), and intense pulsed light devices (IPLs) have also been found to effect collagen remodeling and wrinkle reduction.¹³^–¹⁵ However, the primary indication for these chromophore dependent lasers is reduction of vascular ectasias and/or pigmented lesions.

The Q-switched 1064 nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser was one of the first lasers to demonstrate nonablative reduction of wrinkles. Long-pulse 1064 nm Nd:YAG lasers are also used for reduction of wrinkles and results may be enhanced when combined with 532 nm.¹⁶^–¹⁸ The long 1064 nm wavelength, as with other infrared lasers, allows for deep penetration to the dermis, which is desirable for collagen remodeling and, because it has little absorption by epidermal pigment, this wavelength is safe for all skin types. Studies with Q-switched 1064 nm lasers demonstrate histologic^19,²⁰ and clinical reduction of wrinkles, as well as other collagen remodeling effects, such as reduction of pore size, rough skin texture,²¹ and superficial acne scarring.²²^–²⁴ Dermal collagen remodeling effects are due to both photothermal and photoacoustic vibration, which results from the inherent rapid, short (nanoseconds) pulses of Q-switched lasers.²⁵ In addition to dermal remodeling, Q-switched 1064 nm lasers are also commonly used for tattoo removal,²⁶ reduction of dermal pigmentation such as melasma,²⁷^–²⁹ and reduction of fine dark hair.³⁰ The diverse applications of Q-switched 1064 nm and other chromophore-dependent lasers offer a means to address many aesthetic skin complaints simultaneously.

Light-emitting diodes (LEDs) are a newer type of light-based device that emit a narrow range, or band, of wavelengths. They do not operate based on the theory of selective photothermolysis, but are instead based on the principle of photomodulation, whereby cellular activity is modulated through illumination with particular wavelengths of light.³¹ These devices have been used for mild wrinkle reduction³² and treatment of acne. Several LEDs are available that vary in wavelength and pulsing modes such as blue light devices (400 to 500 nm) which have superficial penetration, and red light devices (570 to 670 nm) which have deeper penetration. The main advantage of LEDs is their ease of use.

LEDs have also been used for skin rejuvenation as part of photodynamic therapy (PDT). PDT refers to selective tissue destruction through the use of a photosensitizing medication that is activated by a laser or light-based device (such as an LED or IPL).³³ A topical photosensitizing medication such as aminolevulinic acid (Levulan^®) is concentrated in particular tissues, such as sebaceous glands and actinically damaged cells. The photosensitizer is activated by a light source resulting in a cytotoxic reaction and destruction of the targeted areas.³⁴ PDT is currently FDA approved for treatment of nonhyperkeratotic actinic keratoses, but is used off label to enhance the results with nonablative lasers for photorejuvenation and wrinkle reduction.³⁵^–³⁷

Reduction of Skin Laxity

Skin laxity is treated with two main types of technologies: broadband infrared and radio-frequency (RF) devices.³⁸ The improvements in laxity are believed to be due to collagen contraction initially, and later to collagen synthesis.³⁹ Broadband infrared devices (such as the Cutera Titan™) emit wavelengths ranging from 1100 to 1800 nm with long pulse widths (of several seconds). Radio-frequency devices (such as Solta Thermage™) employ rapidly alternating current that creates heat when applied to the skin because of the skin’s resistance to the flow of current. Tissue heating with RF devices is controlled by several factors, including the type of electrodes used (e.g., monopolar or bipolar), fluence, and cooling times. These technologies have been shown to improve laxity in many areas of the body including the periocular region, nasolabial folds, jowls, neck, and abdomen.⁴⁰^–⁴⁵ In addition to treatment of wrinkles and skin laxity, RF devices are also used for cellulite reduction.⁴⁶ RF treatments have traditionally been associated with more discomfort than IR treatments, however, new techniques utilizing multiple passes with lower fluences have improved tolerability.⁴⁷

Epidermal Cooling

Cooling of the skin is an important consideration with nonablative wrinkle reduction treatments. Adequate cooling is required to protect the epidermis, but overcooling can reduce clinical effects. In addition, overcooling can induce epidermal injury, particularly in darker Fitzpatrick skin types, resulting in postinflammatory hyperpigmentation. Some nonablative lasers utilize cryogen spray coolants (e.g., 1320 nm) or contact cooling through the tip of the device (e.g., broadband IR). The shorter wavelength devices (e.g., 532 nm and pulsed dye lasers) also employ larger spot sizes with lower fluences to further reduce the risk of epidermal injury. IPL devices have large spot sizes and typically use contact cooling. Due to minimal epidermal energy absorption by 1064 nm and the relatively lower fluences used for wrinkle reduction treatments (compared to leg veins, for example), these devices do not typically utilize cooling.

Patient Selection

Patient selection for wrinkle reduction treatments with nonablative lasers is based on the degree of wrinkling present and patient expectations. Patients with mild to moderate static wrinkles and laxity (Glogau types I through III) are appropriate candidates (see Chapter 19, Aesthetic Principles and Consultation, for a description of Glogau types). Patients with deep static wrinkles and/or severe laxity (Glogau type IV) and those who desire more rapid and dramatic results may be better candidates for more aggressive procedures such as ablative laser resurfacing or surgery.

In patients presenting with wrinkling as well as significant dyschromia and vascular ectasias, the dyschromia and vascularities are typically treated first, using technologies/therapies most appropriate for the predominant presenting issue. Improvements in texture and wrinkles will be more apparent after these other issues have been addressed.

Results with nonablative wrinkle reduction treatments occur slowly, usually 2 to 3 months after the initial laser treatment, and improvements may continue to be seen 6 months post-treatment. A series of five to six treatments is usually required at monthly intervals. Some improvements may be seen immediately post-treatment; however, this is likely due to transient tissue edema. Assessment of patients’ expectations at the time of consultation and commitment to a series of treatments is essential to ensure success with these treatments.

Patients with darker skin Fitzpatrick skin types (IV through VI) have increased risks of complications, such as hyperpigmentation and hypopigmentation, and are best suited to treatment with nonablative lasers that target water (e.g., 1320 nm) and those with longer wavelengths (e.g., 1064 nm). Lighter Fitzpatrick skin types (I through III) may be treated with any of the nonablative laser technologies including those with shorter wavelengths (e.g., 532 nm and pulsed dye lasers).

Indications

• Mild to moderate rhytids

• Mild to moderate skin laxity and crepiness (with RF and broadband IR devices).

Alternative Therapies

Ablative skin resurfacing, with carbon dioxide and erbium lasers, is the gold standard for reduction of wrinkles. Although the fractional method of delivery has reduced the associated recovery time and risk of complications, ablative laser treatments create an open wound and are considered aggressive treatments. Although more aggressive procedures offer greater potential for wrinkle reduction, they require longer recovery times and have greater risks of complications.

Nonlaser treatment options for wrinkle reduction include superficial skin resurfacing with light chemical peels or microdermabrasion, and topical skin care products such as retinoids and exfoliants. More aggressive resurfacing can be performed with deeper chemical peels and operative procedures such as dermabrasion, which utilizes a motorized rotating wire-bristle brush to abrade the skin.

Products Currently Available

See the Resources section at the end of the chapter for a list of laser manufacturers.

Contraindications

See General Laser Contraindications in Chapter 26, Hair Reduction with Lasers.

Advantages of Nonablative Lasers for Wrinkles

• Relative to more aggressive resurfacing procedures, such as ablative treatments with carbon dioxide and erbium lasers, there is minimal recovery time and minimal risk of complications.

• Treatments are readily incorporated into patients’ daily lives and easily combined with other minimally invasive aesthetic procedures.

• Many technologies used for nonablative wrinkle reduction are appropriate for darker skin types (IV and V) and some are even safe with Fitzpatrick skin type VI. More aggressive resurfacing procedures (e.g., ablative laser resurfacing and medium-depth chemical peels) are typically restricted to Fitzpatrick skin types I through III.

Anatomy

Wrinkles result from many factors including skin changes with epidermal hypocellularity, loss of dermal matrix components including collagen, glycosaminoglycans, elastin, and atrophy of subcutaneous adipose tissue. Thinning of the skin combined with repetitive contraction of underlying musculature can etch wrinkles into the skin to form static lines.⁴⁸

Nonablative laser treatments are aimed at reducing mild to moderate static wrinkles. Most of these technologies do so by producing papillary dermal injury, at an approximately 100 to 200 µm (0.1 to 0.2 mm) depth in the skin.^49,⁵⁰ Fractional nonablative laser treatments for wrinkles (e.g., fractional 1550 nm) penetrate up to 300 to 400 µm (0.3 to 0.4 mm).⁹ Nonablative lasers for laxity (e.g., RF lasers) penetrate to the reticular dermis, up to 1 to 3 mm.⁵¹

Procedure Preparation

1. Perform an aesthetic consultation and review the patient’s medical history (see Chapter 19, Aesthetics Principles and Consultation) including history of postinflammatory hyperpigmentation, abnormal scarring, photosensitizing medications or isotretinoin, and previous dermal fillers in the treatment area.

2. Examine the treatment area including assessment of the degree of wrinkling (see Chapter 19 for a discussion of Glogau types). Consider referral for ablative skin resurfacing or surgical intervention in patients with excessive laxity and severe wrinkling (e.g., Glogau type IV).

3. Obtain informed consent (see Chapter 19; also see Appendix A for an informed consent form and patient information handout titled Nonablative Laser Treatments for Wrinkle Reduction).

4. Take pretreatment photographs (see Chapter 19).

5. Determine the Fitzpatrick skin type (see Chapter 19).

6. If the patient has a prior history of herpes simplex or varicella in or near the treatment area, provide prophylactic antiviral medication (e.g., valacyclovir, 500 mg, 1 tablet twice daily) for 2 days prior to the procedure, and continue for 3 days postprocedure.

7. Consider performing test spots prior to the initial treatment for patients with darker Fitzpatrick skin types (types IV through VI). Laser manufacturer’s guidelines for spot size, fluence, and pulse width should be followed. Test spots are placed discretely (under the chin, behind or inferior to the ear) near the desired treatment area and viewed 3 to 5 days after placement for evidence of erythema, burn, or other adverse effect. Inform patients that lack of an adverse reaction with test spots does not ensure that a side effect or complication will not occur with any treatment.

8. Pretreatment skin care products, other than a daily sunscreen, are not required; however, patients will derive added benefit from using rejuvenation skin care products (see Chapter 24, Skin Care Products).