Procedural Dermatology Volume II: Laser and Cosmetic Surgery (eBook)

1 Nonablative Rejuvenation

Daniel Callaghan and Laurel M. Morton

Summary

Nonablative rejuvenation can be achieved with a number of devices and is successfully used to treat many components of the aging process including texture irregularities, pigment irregularities, and tissue laxity. As the name implies, it does so without ablating the epidermis, which provides a lower potential for side effects and a shorter downtime than ablative lasers. The devices used for nonablative rejuvenation are diverse and include intense pulsed light, lasers in the visible light and mid-infrared spectrums, microneedling, radiofrequency, and photodynamic therapy. This chapter explores these interventions in detail and provides clinicians with a roadmap to be able to select the most appropriate treatment for each unique patient.

Keywords: nonablative rejuvenation laser IPL microneedling radiofrequency PDT

1.1 Introduction

“Rejuvenation” is a broad term that describes the process of making the skin appear younger. The aging process, whether it is intrinsic aging programmed by genetics or extrinsic aging due to factors such as the sun, is composed of a number of core features including the following: volume loss, texture irregularities including fine or deep rhytides and acne scars, and pigment irregularities such as telangiectasias, lentigines, or melasma. Today, dermatologists have a widespread number of treatment options available to help rejuvenate their patients’ skin. Although this is no doubt beneficial for patients, as everyone ages differently, it can also be overwhelming and challenging to determine which treatment is best suited for each patient.

Despite the vast number of treatment options available, they all function with the same goal, which is to deliver targeted energy or trauma to the skin to either destroy a lesion such as a lentigo or to stimulate collagen remodeling and neocollagenesis. The devices in our rejuvenation armamentarium include intense pulsed light (IPL), lasers, photodynamic therapy (PDT), microneedling, and radiofrequency (RF). IPL devices work by producing incoherent light of multiple wavelengths to deliver energy to the tissue, whereas lasers use specific wavelengths to target chromophores in tissue including melanin, hemoglobin, or water. PDT combines a photosensitizer such as 5-aminolevulinic acid (5-ALA) with light to target actinic keratoses. Microneedling uses physical trauma, whereas RF devices produce heat through electrical impedance. Beyond this, there are some devices that combine the above, such as microneedling and RF. There is a huge variety of treatment options available made by multiple device companies and all with different treatment parameters.

Ablative technologies such as the carbon dioxide laser, either fully or fractionally ablative, produce impressive results and may be considered by some as the “gold standard” for rejuvenation. However, these devices are associated with a number of adverse effects and a prolonged recovery time, which make them unrealistic options for many patients. For this reason, nonablative rejuvenation treatments have become increasingly popular over the years and are the focus of this chapter.

1.2 Modalities Available

1.2.1 Intense Pulsed Light

IPL sources are not lasers but flashlamp devices that produce noncoherent, multiwavelength light at wavelengths between 400 and 1,200 nm. Clinicians can utilize filters that block wavelengths shorter than the selected filter, thereby emitting only longer wavelengths that can penetrate the skin more deeply. Other factors that can be adjusted with IPL include fluence, pulse duration, and frequency of pulses administered. These are selected based on skin type, target, and severity of the target. IPL provides the benefit of minimal downtime. To reduce the risk of side effects, darker skin types should be treated with filters that employ longer wavelengths, longer pulse durations, and conservative fluences, whereas lighter skin types can be treated with a broader range of wavelengths, narrower pulse durations, and higher fluences. The clinical endpoint for IPL is often described as a mild amount of erythema and darkening of ephelides or lentigines, which develop within minutes of a pulse.

A systematic review by Wat et al found that IPL had a strong or moderate indication for the treatment of lentigines, melasma, rosacea, capillary malformations, and telangiectasias.1 In a split-face study comparing IPL with the 755-nm nanosecond Q-switched (QS) alexandrite, it was demonstrated that IPL was equivalent to QS nanosecond alexandrite for the treatment of solar lentigines, although the QS nanosecond alexandrite was more effective for the treatment of ephelides.2 Wang et al also evaluated IPL for the treatment of melasma and found that the IPL group experienced 39.8% improvement compared with the control group, which was treated with hydroquinone and sunscreen and had a more modest (11.6%) improvement.3 Unfortunately, as has been the case with other melasma studies, results did not prove to be consistently sustainable. In a split-face, randomized, blinded trial, IPL was found to be equivalent to the pulsed dye laser (PDL) for the treatment of facial telangiectasias.4 Additionally, Goldberg and Cutler demonstrated that IPL has some effect at improving facial rhytides.5

Several studies have evaluated IPL for “rejuvenation” in general, including the overall treatment of rhytides, skin coarseness, irregular pigmentation, pore size, and telangiectasias. One study, in particular, selected 49 subjects who were treated with a series of four or more full-face treatments at 3-week intervals and found that 100% of subjects reported some degree of satisfaction and 96% would recommend the treatment.6

1.2.2 532-nm KTP Laser and 595-nm PDL

Based on the theory of selective photothermolysis, there are a number of devices that use a unique wavelength to target a specific pigmentary defect, typically brown or red. Oxyhemoglobin, which is the chromophore targeted by vascular lasers, has absorption peaks at 542 and 577 nm. Absorption of the laser energy heats the oxyhemoglobin and leads to vessel wall damage. Along with IPL, the other energy-based devices that are most frequently used to treat telangiectasias and facial redness include the 595-nm (and rarely 585-nm) PDL and the 532-nm potassium titanyl phosphate (KTP) laser. Patients can typically expect at least 50 to 90% improvement after a series of one to three treatments with these devices7 (Fig. 1.1).

When treating telangiectasias or facial erythema, PDL can be used with a fluence and pulse duration above or below the purpura threshold. In a split-face study comparing purpuric to subpurpuric passes, Iyer and Fitzpatrick found a 43.4% reduction in surface area covered by telangiectasias with a single purpuric pass compared with 35.9% on the side treated with four subpurpuric passes. They also reported that purpuric settings may be required to treat larger caliber vessels.8 Although it may be slightly less effective, patients typically prefer subpurpuric settings with multiple passes because there are fewer adverse effects and less downtime.9

A randomized, split-face study evaluating 20 subjects with Fitzpatrick skin types I to III found that when comparing PDL to IPL, PDL had superior vessel clearance, but there was no significant difference between the effect on irregular pigmentation or skin texture. They did not find any reduction of rhytides with either device.10

In addition to treating telangiectasias and facial erythema like the PDL, the 532-nm KTP laser can be used to treat pigmented lesions. In a split-face study evaluating patients with pigment-related photodamaged facial skin who were treated with the 532-nm KTP alone or combined with the 1,064-nm neodymium:yttrium aluminum garnet (Nd:YAG) laser, the KTP alone was found to be safe and effective, but the addition of the 1,064-nm Nd:YAG provided no appreciable clinical difference.11 In regard to treatment of erythema, a retrospective study of 647 patients treated with the KTP for a number of superficial vascular lesions including but not limited to telangiectasias, spider angiomas, and port-wine stains found that 77.6% of patients at 6 weeks were graded as being “cleared” or having “marked improvement.”12

When comparing the 595-nm PDL to the 532-nm KTP for the treatment of facial telangiectasias in a split-faced study, it was demonstrated that both devices were highly effective. The authors did find that the 532-nm KTP laser appeared to be more effective but caused more swelling and erythema. Greater erythema has also been observed with the new generation of high peak power KTP devices with spike-free pulses.13 As the 532-nm KTP has higher melanin absorption and penetrates the skin more superficially, the 595-nm PDL is a safer option for skin of color, but caution must still be exercised when using aggressive fluences.

1.2.3 694-nm Ruby Laser

Pigmentary issues are a chief concern of patients and one of the earliest and most obvious signs of photoaging. There are a number of devices that take advantage of the theory of selective photothermolysis and target melanosomes and melanocytes including the 532-nm KTP as previously discussed, the 694-nm QS ruby, 755-nm QS alexandrite, or the 1,064-nm QS...