Nonablative Resurfacing 

Updated: Sep 04, 2018
Author: Noah S Scheinfeld, JD, MD, FAAD; Chief Editor: Dirk M Elston, MD 

Overview

Background

Fractional photothermolysis uses an array of small laser beams to create many microscopic areas of thermal necrosis within the skin. These areas of necrosis are deemed microscopic treatment zones (MTZs). Fractional photothermolysis performed within these MTZs completely destroys the epidermis and dermis, but the necrotic injury heals rapidly and adverse effects are few.[1, 2] A large number of new devices have come onto the market, and their individual use must be assessed by the dermatologist individually. Nonablative laser resurfacing has been evolving away from scanning technology to fractional technology.[3]

With nonablative laser, it is difficult to cause a robust fibroplasia on a histologic basis and its ability to induce skin tightening yeilds clinically inconsistent results.[4]

Fractional resurfacing is an effective treatment for hypopigmented scarring on the face.[5] Collawn[6] treated 70 patients with abnormal pigmentation, wrinkles, or scars on their faces and/or extremities for with 2-6 treatments 1-3 weeks apart using the Fraxel laser (Reliant Technologies, Inc). Patients experienced erythema and edema for a few days, followed by light skin exfoliation for a few days, and noted a more even skin color and texture and a decrease in the unwanted melanocytic pigmentation and rhytides. Others have noted that fractional laser reportedly is a useful treatment for pigmentation and texture improvement.[7]

Fractional resurfacing has also been reported to be successful in the treatment of third-degree burn scarring.[8]

Pulsed char-free carbon dioxide laser skin resurfacing has provided a method of removing thin layers of skin with minimal thermal damage. These lasers improve mild, moderate, and severe rhytides, as well as photoaged skin. Laser energy is delivered at the ablation threshold of the skin, without the adverse effects seen with older, nonpulsed, continuous-wave carbon dioxide lasers. The presumed mechanisms of char-free pulsed carbon dioxide laser rhytid improvement are epidermal ablation, dermal damage with collagen remodeling, and thermal contraction.

Carbon dioxide laser resurfacing has been used successfully on nodular and hypertrophic components of port wine stains.[9]

Despite the clinical improvement seen after carbon dioxide laser treatment, the enthusiasm for this system has been tempered by the prolonged healing and significant erythema that commonly occurs following laser treatment. Although this erythema may resolve in 1 month, it commonly lasts up to 6 months. When experienced laser physicians perform carbon dioxide laser surgery, the results are excellent; however, the novice laser physician has not found carbon dioxide systems to be as user friendly. With this significant learning curve, some physicians have shied away from laser resurfacing.

The erbium:yttrium-aluminum-garnet (Er:YAG) laser, with its 2940-nm wavelength, emits laser energy in the mid-infrared invisible light spectrum. This wavelength has 10-15 times the affinity for water absorption compared with the carbon dioxide wavelength (10,600 nm). It is this fact that leads to the difference in clinical response observed after treatment with these 2 lasers. The Er:YAG laser wavelength is at the peak of water absorption. Er:YAG laser treatment leads to epidermal ablation and dermal remodeling. Unlike carbon dioxide lasers, these systems produce little thermal effect.

The Er:YAG laser is a true ablation laser. This laser is unlike carbon dioxide lasers, which cause both vaporization and desiccation. Both the Er:YAG laser and the pulsed char-free laser have water as the absorbing chromophore. The Er:YAG laser produces only about 5-20 µm of thermal damage per impact as opposed to the 50-125 µm of additional thermal damage observed with each pass of the carbon dioxide laser. Carbon dioxide lasers produce a significant thermal effect; this residual thermal damage becomes a heat sink for the next pass of the carbon dioxide laser. This damage leads to desiccated collagen with a resultant increase in new collagen production. Such an effect would not be expected after Er:YAG laser treatment.

The duration of erythema after Er:YAG resurfacing is usually less than with carbon dioxide laser treatment because Er:YAG laser treatment often involves more superficial ablation and leaves minimal thermal damage. Wound healing and recovery time following Er:YAG laser treatment is generally shorter, making it ideal for resurfacing relatively young people who lack deep wrinkles or extensive photodamage. However, a draining wound is still created with Er:YAG laser technology.

Both carbon dioxide laser and Er:YAG laser technology, although promising in their benefits, sometimes are accompanied by untoward adverse effects and complications. The most common of these, as mentioned above, is postoperative erythema, an adverse effect experienced by virtually all patients treated with these modalities. Other potential risks induced by ablative, dermal wounding modalities include delayed healing, postoperative pigmentary changes, and scarring.

If a dermal wound and new collagen formation is the primary mechanism behind the improvement seen after laser resurfacing, techniques that induce a dermal wound without epidermal ablation theoretically should lead to cosmetic improvement of dermal photodamage. This arena of nonablative dermal remodeling is a new area of laser technology.

Handley et al[10] noted that adverse events can occur with nonablative cutaneous visible and infrared laser treatment.

Recent studies have shows that Fitzpatrick skin types IV to VI lasered with a 1,550-nm erbium-doped fractional type nonablative laser had a low incidence of treatment-related pigmentary alteration.[11, 12]

It seems clear that nonablative laser has a place in the treatment of patients who are younger than 50 years and have nonsagging skin; it can yield results similar to ablative procedures in such patients.[13]

Finally, nonablative lasers have a place in improving the appearance of scars and grafts in patients after Mohs micrographic surgery.[14, 15]

The dual-spot-size carbon dioxide ablative fractionated laser has been used effectively to treat acne, with few of the adverse effects of a truly ablative laser.[16, 17]

Weiss et al[18] noted that based on a prospective clinical evaluation, 1440-nm laser treatment delivered by microarray is effective for treating photoaging and scars, specifically inducing neocollagenesis in the remodeling of scars and rhytides.

Trellas et al[19] noted that no single nonablative laser can achieve all the specific effects needed for effective skin rejuvenation, and they suggest that combinations of treatments are the most useful modes of treatment. Fractional resurfacing has largely replaced other ablative technologies, and nonablative techniques have become more widespread.

Although nonablative treatments are useful, they are still not as effective as ablative treatments. This was highlighted in a study by Ong and Bashir; ablative fractionated laser induced an improvement range between 26-83% whereas nonablative fractionated laser had an improvement range between 26-50%.[20]

Also see the Medscape article Nonablative Facial Skin Tightening.

History of the Procedure

In one of the first studies evaluating a nonablative approach to dermal remodeling, a 1064-nm Q-switched neodymium:yttrium-aluminum-garnet (Nd:YAG) laser was used in an attempt to improve rhytides. Eleven research subjects with perioral or periorbital rhytides were treated with a Q-switched Nd:YAG laser at 5.5 J/cm2 and a 3-mm spot size. All research subjects had skin phenotypes I and II, and all had class I or II rhytides. The authors sought a nonspecific clinical endpoint of pinpoint bleeding, as demonstrated in the image below.

Petechiae seen after nonablative treatment with a Petechiae seen after nonablative treatment with a high-fluence Q-switched Nd:YAG laser.

The research subjects were treated only once and were evaluated 7, 30, 60, and 90 days after treatment. At follow-up, each research subject was evaluated for improvement of rhytides, healing, pigmentary changes, and erythema. In 3 patients (2 perioral and 1 periorbital), the authors noted improvement that was thought to be comparable to that following ablative resurfacing. In 6 patients (3 perioral and 3 periorbital), clinical improvement was noted but was not thought to be as significant as that observed with an ablative laser system. In 2 patients (1 perioral and 1 periorbital), no clinical improvement was noted. In those research subjects where clinical improvement was noted, the clinical changes were consistent the full 90 days of the study. No pigmentary changes or scarring was noted in any of the treated research subjects. At 1 month, 3 of the 11 research subjects showed persistent erythema at the treated sites. At 3 months, all erythema was resolved.

Dermal remodeling is thought to occur through increased collagen I deposition with collagen reorganization into parallel arrays of compact fibrils. Such an effect, the authors suggested, might occur with nonablative laser systems as well as ablative laser systems. Of note, the greatest improvement occurred in individuals who had the most persistent erythema. This finding suggested that the degree of improvement following any dermal wounding approach might be directly related to the degree of induced wound.

This study was expanded when the nonablative dermal remodeling effects of a Q-switched Nd:YAG laser was potentiated by the use of a topical carbon-assisted solution. Two hundred forty-two solar damaged anatomical sites on 61 human subjects were treated with three 1064-nm Q-switched Nd:YAG laser treatments. Parameters of treatment included a fluence of 2.5 J/cm2, pulse duration of 6-20 nanoseconds, and a spot size of 7 mm. The treatment sites were evaluated at baseline, 4, 8, 14, 20, and 32 weeks for skin texture, skin elasticity, and rhytid reduction. All sites were treated at a baseline visit and later at 4 and 8 weeks. Adverse events were recorded throughout the study.

In this study, a low fluence Q-switched Nd:YAG laser was used for treating mildly solar-damaged skin. Unlike the previous study, no epidermal disruption occurred when the lower fluences were used. The Q-switched Nd:YAG laser energy is not well absorbed by tissue water; it is nonselectively placed within the dermis. The 1064-nm wavelength results in relatively deep penetration into the skin, which is indicative of minimal laser-tissue interaction. As a result, cellular damage is localized to the tissue immediately adjacent to the carbon, nontargeted tissue is minimally affected, and less than 10% of the typical energy output from carbon dioxide lasers is required for the treatment. At 8 months, the investigators reported improvement in skin texture and skin elasticity, as demonstrated in the images below, as well as rhytid reduction compared with baseline. Most adverse events were limited to mild, brief erythema.

Periorbital rhytides before treatment with a carbo Periorbital rhytides before treatment with a carbon-assisted low-fluence Q-switched Nd:YAG laser.
Improvement in rhytides after treatment with a car Improvement in rhytides after treatment with a carbon-assisted low-fluence Q-switched Nd:YAG laser.

Other nonablative lasers, such as the pulsed-dye laser, have been shown to improve dermal collagen. Histopathologic examination of scars treated with a 585-nm pulsed-dye laser revealed improvement in dermal collagen. The number of regional mast cells is increased in scars treated with pulsed-dye lasers. Because mast cells elaborate a variety of cytokines, their presence following irradiation and accompanying tissue revascularization may provide an explanation for therapeutic improvement following laser treatment. Using this concept, Zelickson et al[21] evaluated the use of a pulsed-dye laser in the treatment of rhytides. In a small pilot study, the authors noted improvement. However, the study results were tempered by the cosmetically unacceptable purpura that is usually observed following treatment with this laser.

Problem

The key problem in assessing evaluations of nonablative resurfacing in the last 5 years has been understanding its ability to induce objective clinical improvement.

Investigators using nonablative lasers have noted that the induction of new collagen creations are not specific to a wavelength. That is, identical alterations of collagen can be histologically demonstrated using the Er:glass laser, Nd:YAG, and diode lasers. The primary effects appear to be thermal injury to the dermis, inducing collagen remodeling and formation instead of vascular injury. What may be occurring is dermal remodeling or toning in a parallel fashion to the healing response elicited by an injury that initiates collagen regeneration, turnover, and deposition.[22]

Histological alteration do not exactly mirror clinical enhancement of skin. Results vary, and studies even of the same lasers with similar (but almost always slightly different) settings and parameters report different results (ie, some with clinically significant change and some without objective alterations in the skin).

Studies have been performed on pulsed-dye, 585- to 595-nm lasers; Er:glass, 1540-nm lasers[23] ; Nd:YAG, 1320-nm lasers; diode, 1450-nm lasers; and intense pulsed-light, 560- to 640-nm lasers with a cutoff filter.[24]

It might be best understood that Nonablative laser treatments are likely not the most effective treatments for rhytid reduction. However, they seem to be effective and useful modalities for amelioration of scars and superficial dyschromias. Obviously, for minimal facial damage, they allow patients to pursue their regular activities and thus are useful and important treatment options.[25]

Wanner et al[26] found that fractional photothermolysis for the treatment of facial and nonfacial cutaneous photodamage using a 1550-nm Er-doped fiber laser is a useful nonablative laser treatment.

Orringer et al[27] reported from a randomized, controlled, split-face clinical trial that 1320-nm Nd:YAG laser therapy in effective for treating acne vulgaris.

de Angelis et al reported good results using the fractional nonablative erbium:glass laser for treatment of striae rubra and alba ranging in maturation age from 1-40 years.[28]

Indications

Nonablative procedures are ideal for the younger person who wishes to improve the quality, the tone, and the texture of his or her skin. It is a technique ideally suited for the individual with early photoaging, not for one with class III rhytides. Nonablative treatment is also a good modality for saucerized acne scars and as a maintenance procedure following other more aggressive ablative laser procedures. Also see Facial Analysis for Skin Resurfacing.

Relevant Anatomy

Nonablative techniques have mainly been used on facial skin; however, interest is increasing in the role of these techniques on the neck, the hands, and possibly other areas of the body.

Contraindications

The techniques, because of their nonablative nature, appear to be safe. However, the risk of scarring is always present, which is true for any cosmetic procedure.

 

Treatment

Medical Therapy

The most commonly used modalities for nonablative resurfacing are the 585-595-nm pulsed-dye lasers, the 1320-nm Nd:YAG laser, the 1450-nm diode laser, the 1064-nm Q-switched Nd:YAG laser, and the intense pulsed light source. This field is rapidly evolving, and newer modalities are expected over the next few years. A novel 1,550-nm erbium-doped laser (Fraxel, Reliant Technologies Inc.) has been shown to be effective in the treatment of photodamaged skin and scars with minimal postoperative recovery.[6] Combinations of treatments with nonablative resurfacing can yield improved cosmetic effects.[29] Nonablative lasers can be combined with topical bimatoprost to enhance repigmentation, but this effect requires further investigation.  In Asians, topical corticosteroids after laser resurfacing with ablative fractional carbon dioxide laser reduce the risks of postinflammatory hyperpigmentation.[30]

Surgical Therapy

Currently used nonablative systems are based on the studies discussed below. New systems include the 1927-nm system of fractional thulium fiber that produces laser light.

In 2012, articles noted that nonablative lasers have been used to treat burn scars, striae, macular seborrheic keratosis, actinic keratosis, and a variety of neoplastic and scarring conditions, including treatment of post-Mohs surgical scarring and skin grafting. They can be used with ablative devices to enhance effect.[31] Blinded physician global assessment for hypertrophic scars was unable to prove the clinical effect of the 1540-nm nonablative fractional system laser.[32] . Some claim that they can repigment hypopigmented scars, but the mechanism and consistency of this result must be further defined. They may play a role in hand rejuvenation.

Treatment of melasma using fractional photothermolysis (1550-nm Fraxel SR laser) achieved a greater than 50% improvement in 5 of 8 patients treated (3-8 times) with long-term follow-up.[33] However, at conferences, dermatologist with experience with this condition have indicated they have not been able to replicate this level of effect.

In 2001, Rostan et al[34] studied 15 patients using the long-pulse flashlamp pumped pulsed-dye laser (LPDL) with and without cooling to ameliorate rhytides, to stimulate collagen synthesis, and to facilitate dermal remodeling. Eleven of 15 patients showed improvement of the laser-treated cheek, while only 3 of 15 patients showed a better appearance on the cryogen-treated side. Histologic specimens had more activated fibroblasts and demonstrated more positive procollagen staining on the LPDL-treated cheek. Thus, the LPDL can be a useful nonablative modality.

Bjerring et al[35] have shown increased levels of collagen precursors following treatment with a 350-μsec pulsed-dye laser. This laser is different from the usual pulsed-dye lasers currently used in cutaneous laser treatment because it emits shorter pulse width laser irradiation at low fluences. In a recent study, the use of intense pulsed light was also evaluated in the treatment of rhytides. Thirty female research subjects aged 35-65 years with Fitzpatrick type I-II and class I-II skin phenotypes were treated. Treatment areas included the periorbital, the perioral, and the forehead regions.

Over a period of 10 weeks, 1-4 treatments were provided. Noncoherent intense pulsed light was delivered to the skin by using a 645-nm cutoff filter. This technique leads to an emission of light with wavelengths of 645-1100 nm. Light was delivered through a bracketed cooling device in triple 7-msec pulses with a 50-msec interpulse delay between the pulses. Delivered fluences were between 40-50 J/cm2. The author evaluated the degree of improvement 6 months after the last treatment. Complications were also evaluated at this time. Clinical improvement was divided into the following 4 quartiles: no improvement, some improvement, substantial improvement, and total improvement.

Six months after the final treatment, 5 research subjects were noted to have no improvement. Similarly, no research subjects were noted to have total improvement. Sixteen research subjects showed some improvement, while 9 showed substantial improvement. All research subjects were evaluated for pigmentary changes, posttreatment blistering, erythema, and scarring. Three of the 30 research subjects were noted to have blistering immediately after treatment. All 30 research subjects had posttreatment erythema. Six months after treatment, no pigmentary changes, erythema, or scarring was noted. The author concluded that intense pulsed light could improve some rhytides, as demonstrated in the images below.

Periorbital rhytides before treatment with an inte Periorbital rhytides before treatment with an intense pulsed light source.
Improvement in rhytides after treatment with an in Improvement in rhytides after treatment with an intense pulsed light source.

New collagen formation and improvement of age-related vascular and pigmented lesions can follow treatment with this nonlaser technology. However, the changes appear to be subtler than those seen with ablative techniques.

The first specifically nonablative laser to be solely marketed to the physician community is a 1320-nm Nd:YAG laser. The goal of this system, similar to that of the previously described systems, is improvement of rhytides without the creation of a wound. The 1320-nm wavelength is advantageous in its high scattering coefficient. Thus, the laser irradiation scatters throughout the treated dermis after nonspecific absorption by dermal water.

In 2001, Pham[36] reported that the CoolTouch (Roseville, Calif) laser that blends an Nd:YAG, 1320-nm wavelength beam and thermal-sensing cryogenic spray was an effective nonablative treatment modality.

In 2004, Fulchiero et al[37] reported tandem treatment with needle subcision of acne scars and 1320-nm Nd:YAG nonablative laser resurfacing. They deemed this double-pronged treatment modality to be a well-tolerated and highly effective regimen compared with either modality alone.

In 2005, Bellew et al[38] reported on 29 patients treated with nonablative laser skin resurfacing with a 1320-nm Nd:YAG laser. They demonstrated significant positive changes in the appearance of facial acne scars and reported no adverse effects.

In August 2004, Sadick and Schecter[39] reported on 7 persons with photoaged hands. These patients underwent 6 monthly treatments with a 1320-nm Nd:YAG laser. They assessed skin smoothness improvement objectively, and patients also evaluated the results. The scale used was a 6-point improvement scale with 1 point for no improvement, 2 points for 20% improvement, 3 points for 40% improvement, 4 points for 60% improvement, 5 points for 80% improvement, and 6 points for 100% improvement. The mean improvement by objective assessment was 2.4 points. They noted objective improvement in 4 of 7 patients. In these 4 patients, a mean improvement score of 3.5 points was recorded. The mean improvement reported by the patients was 3.1 points.

In July 2004, Sadick and Schecter[40] exposed 8 persons with facial acne scars to 6 monthly treatments with a 1320-nm Nd:YAG laser with built-in cryogen cooling. They assessed acne scar improvement after treatment with the 1340-nm laser. They assessed the improvement objectively, and, again, the patients also evaluated the results. The 6-point improvement scale was also used again, with 1 point for no improvement, 2 points for 20% improvement, 3 points for 40% improvement, 4 points for 60% improvement, 5 points for 80% improvement, and 6 points for 100% improvement. They noted the mean improvement by objective assessment was 3.9 points (P = .002) at 5 months and 4.3 points (P = .011) at 1 year. The patient evaluations yielded similar scores of 3.6 points (P = .002) at 5 months. These researchers stated that acne scar improvement achieved statistical significance at the 5-month and 1-year milestone evaluation points.

In 2003, Rogachefsky et al[41] studied 12 patients with atrophic facial acne scars (N = 6) or a combination of atrophic and pitted, sclerotic, or boxcar scars (N = 6). These patients received 3 laser exposures with a 1320-nm laser. Both the researchers and the patients evaluated the scars before the initiation of treatment and at 6 months subsequent to the final laser exposure. A 10-point rating scale was used. Rogachefsky et al[41] found an average acne scar enhancement of 1.5 points (P = .002). The patient enhancement evaluations scored 2.2 points (P = .01). Patients rated the acne scars as worse compared with the ratings of Rogachefsky et al.[41] The researchers concluded that the 1320-nm was a useful and effective modality for ameliorating acne scars, and no adverse effects were reported at 6 months.

In 2002, Fatemi et al[42] used a 1320-nm laser on 10 patients and then performed biopsies. They stated that their data indicated that in addition to dermal collagen heating with subsequent collagen healing, nonablative resurfacing can engender subclinical epidermal injury that somehow improves appearance. Fatemi et al[42] speculated that acute alterations of superficial blood vessel injury somehow linked to cytokine release are also important factors. They concluded based on histologic findings that 3 passes with fluence and cooling adjusted a maximum temperature of 45-48°C yields optimal clinical improvements.

In the study by Nelson et al,[43] one or more passes of a 1320-nm Nd:YAG laser were used on photoaged skin. The waveform consisted of 3200-µsec laser pulses at a 100-Hz repetition rate. Laser energy was delivered through a 5-mm spot size with fluences up to 10 J/cm2. A dynamic cryogen cooling technique was applied immediately prior to laser treatment to produce selective subsurface skin heating without epidermal damage. Immediately after treatment, mild edema and erythema appeared in the treated skin. These adverse effects resolved within 2 days. At 2 months after treatment, facial rhytides improved notably. No persistent erythema or pigmentary changes were observed.

The currently available model of this 1320-nm Nd:YAG laser is accompanied by a unique handpiece with 3 portals. One portal contains the cryogen spray that cools the epidermis prior to and during treatment, another portal emits the 1320-nm Nd:YAG laser irradiation, and the third portal contains a thermal sensor. Fluences that are used with the currently available models vary from 30-40 J/cm2. Such fluences lead to peak measured temperatures of 42-48°C. Patients are usually treated at 2- to 4-week intervals and can be expected to show the degree of improvement expected from a nonablative approach.

Consistent with the noted clinical improvement is the histologic replacement of the irregular collagen bands with organized new collagen fibrils, as demonstrated in the images below.

Histologic findings consistent with solar elastosi Histologic findings consistent with solar elastosis.
Histologic findings 6 months after 4 treatments wi Histologic findings 6 months after 4 treatments with a 1320-nm Nd:YAG laser. Note the upper papillary dermal fibrosis.

This laser has also been used as part of a full-face antiaging approach because it produces new collagen formation, as demonstrated in the images below. Eyelid tightening and improved aperture through nonablative fractional resurfacing has also been reported.

Patient with almost no rhytides seeking full-face Patient with almost no rhytides seeking full-face 1320-nm Nd:YAG laser antiaging treatment.
Nonablative resurfacing. Six months after 1320-nm Nonablative resurfacing. Six months after 1320-nm Nd:YAG laser treatment.

The newest version of this laser leads to extremely safe and fast nonablative treatment through the use of either pretreatment cryogen cooling or posttreatment cryogen cooling and delivery of laser energy through a 10-mm spot size.

A 1450-nm diode laser has also been shown to be effective for the nonablative treatment of photoaged skin. The 1450-nm wavelength is extremely well absorbed by water. The laser also uses cryogen cooling to protect the epidermis before, during, and after treatment, as demonstrated in the images below.

Periorbital rhytides before treatment with a 1450- Periorbital rhytides before treatment with a 1450-nm diode laser.
Improvement in rhytides after treatment with a 145 Improvement in rhytides after treatment with a 1450-nm diode laser.

In 2005, Hohenleutner et al[44] reported on treatment of 30 facial areas with a 1450-nm diode laser. The treating laser surgeon and 2 blinded observers reviewed prelaser and postlaser exposure photographs. While as much as 35% enhancement seemed to occur in some patients, little concordance was achieved between the 3 reviewers. Thus, objective data did not demonstrate the efficacy of nonablative treatment of rhytides with the 1450-nm diode laser.

In 2004, Tan et al[45] reported a series of patient treated with the 532-nm laser on one side of the face and with the 532- and 1064-nm lasers to the other side of the face, followed by 3 treatments with the 1064-nm laser to both the right and left cheeks. They assessed skin quality (ie, visual dryness, roughness, uneven pigmentation) before, during, and up to 4 months after laser exposure. They noted greater than 25% improvement in overall skin quality for more than 30% of patients at the 1-month follow-up and for more than 40% of subjects at 4-month follow-up. The skin qualities most enhanced were visual dryness, roughness, and uneven pigmentation. Tan et al did not report adverse effects, and they stated that persons who receive more treatments with the 1064-nm would have greater improvement, but this outcome did not achieve statistical significance.

Dayan et al[46] in 2003 in a study of 1064-nm laser treatment in 51 patients found that it reduced coarse wrinkles and skin laxity and induced an overall improvement in the appearance of skin. Most patients received 7 treatments. Adverse effects were minimal.

In 2004, Tanzi and Alster[47] reported their important study involving 20 people with Fitzpatrick skin types demonstrating mild-to-moderate atrophic facial acne scars. These 20 persons were randomly exposed to 3 successive monthly laser exposures with the nonablative long-pulsed 1320-nm Nd:YAG and 1450-nm diode lasers. Tanzi and Alster[47] found that the 1320-nm and 1450-nm lasers provided enhancement with minimal untoward changes. However, the 1450-nm diode laser provided greater clinical scar amelioration when used by at the settings Tanzi and Alster[47] used.

In 2002, Lupton et al[23] reported on a study of the 1540-nm Er-doped phosphate glass laser operated by one laser surgeon. They found that the 1540-nm Er-doped phosphate glass laser was effective. Interestingly, histologic dermal alteration did not appear immediately; instead, several months after exposure to the 1540-nm laser, a dermatopathologist was able to report that a greater quantity of dermal collagen was present. Lupton et al[23] noted slow, progressive clinical and sustained improvement of rhytides in most patients.

In 2001, Fournier et al[48] reported on their study of 60 patients (mean age 47 y) who had skin phototypes ranging from I-IV and who were exposed for 4 treatments over 6-week periods to the 1540-nm Er:glass laser with contact cooling for nonablative skin remodeling. The focus was perioral and periorbital rhytides. All patients experienced subjective improvement. Ultrasound imaging data showed a 17% increase of dermis thickness (P< .005), and histologic data demonstrated new collagen formation. Thus, Fournier et al[48] concluded that the 1540-nm was a useful nonablative modality.

Fractional resurfacing has been used to decrease the size and extent of atrophic facial acne scars in various skin types, including Asian skin.[49, 50] Fractional resurfacing has also been noted to improve and tighten eyelid skin.[51]

The low-density, low-energy, nonablative, 1440-nm fractional laser can produce a slight improvement after four treatments on certain aspects of photodamage, without long-term adverse effects.[52]

A 1927-nm wavelength laser can be used effectively for nonablative skin resurfacing.[53]

Postoperative Details

Graber et al[54] studied the use of the fractionated 1550-nm laser retrospectively from 961 treatments. Of these treatments, 7.6% of patients developed complications. The most common adverse effects were acneiform eruptions (1.87%) and herpes simplex virus eruptions (1.77%). Of note, darker-skinned patients experienced more pigmentary alteration.

After ablative fractional carbon dioxide laser resurfacing, reduced erythema and rapid healing was achieved with autologous platelet-rich plasma application.[55]

Complications

Erythema and edema may be seen after treatment. Scarring, although extraordinarily rare, can be seen with any modality. Complications related to herpes simplex virus infection have been reported.[56]

Outcome and Prognosis

All treated patients should note improvement in the quality, the tone, and the texture of their skin. Mild improvement in early rhytides may also occur. The outcome is maximized when other adjunctive agents, such as fillers, botulinum toxin, and microdermabrasion, are used. Ongoing treatment is to be expected. In a 2010 literature review, Tierney and Hanke found 10 studies that reported histologic evidence of cutaneous repair of photodamaged skin with the use of combination treatments to treat photoaging; reported treatments included nonablative and ablative laser resurfacing, topical retinoids, and topical photosensizers with lasers and light sources.[29]

Future and Controversies

Nonablative or subsurface remodeling represents the newest approach to improving photodamaged skin. The degree of collagen remodeling is not expected to be as great as that seen with other, more destructive ablative approaches; therefore, the nonablative technique is meant for individuals who do not wish to take time away from their daily activities to improve the quality of their sun-damaged skin through laser techniques. The technique is also not meant for individuals with extensive solar-induced epidermal pigmentary changes. Those individuals are best treated with either an ablative laser or a specific pigmented lesion laser. The histology of nonablative resurfacing has been further defined in 2014.[57]

Combinations of nonablative laser treatment with medical treatment present an interesting new treatment modality.[58] Repigmentation of scars that are hypopigmented using an erbium-doped 1,550-nm fractionated laser in combination with topical bimatoprost works better than either treatment alone. Other combination of fractionated laser with topical medications are being explored.

Present studies are examining comparisons between the currently available systems. In the future, lasers or nonlaser radiofrequency devices may be created that can cause the same degree of improvement as ablative systems without the potential complications and down time.