Evaluation of the safety and efficacy of the dual wavelength picosecond laser for the treatment of benign pigmented lesions in Asians.

BACKGROUND AND OBJECTIVES: Cutaneous pigmentary disorders are both more common and more difficult to treat in patients with skin color given the higher melanin content in the epidermis. Although Q-switched lasers are widely considered to be the standard treatment for both epidermal and dermal pigmentary conditions, a very high risk of post-inflammatory hyperpigmentation (PIH) of up to 25% is seen in patients with skin of color. Recently, the novel picosecond laser with pulse durations operating at sub-nanosecond domains has been shown to be effective in tattoo removal and in the treatment of acne scars. The objective of this study is to examine the safety and efficacy of the dual wavelength picosecond laser for the treatment of benign pigmented skin lesions in Asian patients. METHODS: Twelve subjects with benign pigmentary disorders and Fitzpatrick skin types III to IV were recruited in a prospective clinical study to examine the safety and efficacy of the dual wavelength picosecond laser. Patients were treated at approximately 2-6 week intervals depending of the type of lesion. The primary efficacy endpoint is the global percent of clearance which was evaluated by blinded observers using post treatment photographs compared to baseline photographs. Safety was evaluated before and after each laser treatment and patients were asked to rate the level of pain according to the Visual Analog Scale after each treatment session. Patient satisfaction was assessed at the completion of treatment with questionnaires. All patients were followed up at 4, 8, and 12 weeks after the last treatment session. RESULTS: The pigmentary conditions treated included melasma, freckles, lentiginies, café au lait macules, and Hori's macules. Three months after treatment, 53.8% of all pigments achieved excellent response (75-94% lightening,) 30.8% of pigments achieved good response (50-74% lightening,) and 7.7% of pigments achieved both fair (25-49% lightening) and poor responses (0-24% lightening), respectively. The average number of treatment sessions required to reach at least 50% clearance was 4.5 for melasma, 1 for freckles, 1.5 for lentigines and 1 for café au lait. The patient with Hori's macules did not reach 50% clearance after a total of six treatments. Sixty three percent of patients reported satisfaction in the subjective assessment, while 27.3% were neutral and 9.1% were very dissatisfied. The post inflammatory hyperpigmentation rate was 4.8% and 6.5% of subjects developed blistering as a side effect of treatment. CONCLUSION: The dual wavelength picosecond laser is a safe and effective treatment of benign pigmentary conditions in patients with skin of color. In particular, superior clinical efficacy is demonstrated for treatment of freckles and lentigines with a low risk of PIH. Lasers Surg. Med. 51:14-22, 2019. © 2018 Wiley Periodicals, Inc.

Evaluating the safety and efficacy of the 1,440-nm laser in the treatment of photodamage in Asian skin.

BACKGROUND AND OBJECTIVE: As the demand for diminished procedure-associated downtime continues to increase, nonablative fractional laser resurfacing is becoming a more popular intervention in the progression of photoaging. Patients with pigmented skin and a mild degree of photodamage may be particularly suited for a less intensive laser treatment. In this study, we have evaluated the safety and efficacy of a low energy, low density 1,440-nm fractional laser in the treatment of multiple signs of photoaging including dyspigmentation, wrinkling, tissue laxity, enlarged pores, and skin roughness in Asians. STUDY DESIGN/MATERIALS AND METHODS: Ten Chinese subjects with Fitzpatrick skin types III-V and visible signs of photodamage participated in this study. Patients received four treatments at 2-week intervals with a 1,440-nm diode-based fractional laser. Photographs were taken at baseline, 2 weeks after each of the first three treatments and 4 weeks after the final treatment. Images were evaluated independently by two physicians. Clinical improvement and adverse events were analyzed. Discomfort, heat sensation and overall patient satisfaction associated with the procedure were also quantified. RESULTS: In this prospective single-arm study, signs of photoaging were examined after treatment with the 1,440-nm laser. Here we show that a series of four treatments with this device produced a mild improvement in skin texture, pigmentation, and wrinkling. Changes in pore size and skin laxity failed to reach statistical significance. Immediate after-effects of the procedure included erythema and edema which were transient and left no permanent sequela. A significant proportion of patients reported some degree of discomfort during the procedure despite use of a topical anesthetic. One patient developed a discrete, localized area of post-inflammatory hyperpigmentation which completely resolved by the final follow up visit. CONCLUSION: The low energy, low density nonablative 1,440-nm fractional laser produces a mild improvement in select signs of photodamage after four treatments without any long-term adverse effects.

A case series of facial depigmentation associated with low fluence Q-switched 1,064 nm Nd:YAG laser for skin rejuvenation and melasma.

BACKGROUND AND OBJECTIVE: In recent years, "laser toning" using low fluence, large spot size, multiple passed Q-switched 1,064 nm Nd:YAG laser has gained much popularity in Asian countries for non-ablative skin rejuvenation and the treatment of melasma. This case series highlights one of the complications associated with laser toning, which is facial depigmentation. MATERIALS AND METHODS: Fourteen patients with laser toning-associated facial depigmentation were assessed with cross-polarized and ultraviolet (UV) photographic images. The laser toning regimens received by these patients, as well as the treatment given for depigmentation, were analyzed retrospectively. RESULTS: All 14 patients were Chinese females, 9 of whom received laser toning for non-ablative skin rejuvenation and the other 5 for melasma. The treatment regimens received by these patients were highly variable. The total number of treatments received ranged from 6 to 50 (mean 22.07). In all cases, UV photographic images demonstrated facial mottled depigmentation. Laser toning failed to significantly improve melasma in all five patients. Five patients received targeted narrowband UVB for depigmentation with good clinical results. CONCLUSIONS: Laser toning with low fluence Q-switched 1,064 nm Nd:YAG laser for skin rejuvenation and melasma can be associated with mottled depigmentation. With laser toning being frequently performed, this complication may become more commonly encountered in clinical practice. The depigmentation can appear after only a few treatment sessions, and can cause much disfigurement, especially in cases with background melasma. Further studies on laser toning are needed with the view to optimizing efficacy and minimizing side-effects.

The use of non-ablative fractional resurfacing in Asian acne scar patients.

BACKGROUND AND OBJECTIVES: Non-ablative fractional resurfacing (NA FR) has been shown to be effective for photorejuvenation and acne scarring. Previous studies indicated that density, more than pulse energy, was associated with post-inflammatory hyperpigmentation (PIH) in Asians. The objective of this retrospective study was to assess the efficacy and complications of eight passes of NA FR ('full-NA FR') with the 1,550 nm erbium-doped fibre fractional laser (Fraxel SR laser system, Solta Medical, Hayward, CA) versus four passes ('mini-NA FR') with comparable pulse energy and treatment level as 'full-NA FR', but double the number of treatment sessions in Asian acne scar patients. MATERIALS AND METHODS: Forty-seven Asian atrophic facial acne scar patients who received full-face full-NA FR or mini-NA FR treatments between December 2005 and February 2009 were included. All photographic images captured with the Canfield Visia CR system at baseline and follow-ups were assessed for clinical efficacy and complications by an independent, non-treating and blinded physician. RESULTS: The total treatment densities for full-NA FR and mini-NA FR were 442.5 and 210.5 MTZ/cm(2), respectively. For full-NA FR, the PIH risk was 18.2% with cross-polarized images compared to 6.0% for mini-NA FR. This difference was statistically significant (P < 0.001). Improvement in skin texture, acne scarring, enlarged pores and overall pigmentation irregularity all reached statistical significance at last follow-up compared to baseline. There was no statistically significant difference in clinical efficacy between three full-NA FR and six mini-NA FR treatments. CONCLUSIONS: NA FR was effective and safe in Asians. By reducing the number of passes and the total treatment density, the risk of PIH could be reduced. Meanwhile, clinical efficacy could be maintained by increasing the total number of treatment sessions.