In the field of photoelectric treatment of melasma, 1064nm wavelength Q-switched laser (Q-switched Nd:YAG laser) and picosecond laser are one of the most widely used choices in clinical practice. Their treatment mechanism, parameter optimization and effects on the skin barrier deserve in-depth discussion.

1064nm is a near-infrared wavelength that can penetrate the epidermis directly to the dermis. Melanin particles have a moderate degree of absorption of this wavelength and can break up melanin particles in the epidermis and shallow dermis through photothermal effect, promoting macrophage phagocytosis and clearance. Compared with short-wavelength lasers (such as 532nm), it has a deeper penetration depth and is suitable for mixed or dermal melasma, reducing the risk of epidermal damage.

In Q-mode (pulse width in nanoseconds), laser energy is released in a very short time to generate photomechanical waves, which can shatter melanin particles; picosecond mode (pulse width in picoseconds) further reduces thermal damage, and more accurately breaks up melanin through the "photoacoustic effect", reducing thermal damage to surrounding tissues. It is especially suitable for Asians with thicker dermis structure and skin prone to pigmentation.

Large spot (diameter ≥ 8mm), low energy, low frequency or dot matrix mode (such as 1064nm dot matrix laser) are often used in clinical practice to reduce the thermal damage to the epidermis in a single treatment. Large spot reduces the spot overlap rate and avoids energy accumulation; low energy avoids excessive damage to the stratum corneum, and the dot matrix mode forms controllable micro-damage through micro-channels to stimulate epidermal renewal without destroying the integrity of the barrier.

Appropriate energy laser stimulates keratinocytes to accelerate differentiation, enhances the synthesis of keratin and moisturizing factors, increases the water content of the stratum corneum and reduces transepidermal water loss; at the same time, it promotes the production of lipids such as ceramide, repairs the intercellular lipid bilayer, and enhances the barrier's ability to lock in moisture and resist.

Activates the skin's self-repair mechanism, releases growth factors to promote basement membrane repair, enhances antioxidant enzyme activity and reduces free radical damage; regulates skin pH, optimizes microbial flora, inhibits excessive proliferation of inflammatory bacteria, and reduces the risk of inflammation.

Inhibits pigment-promoting factors (NGF, IL-1α), strengthens the negative regulation of keratinocytes on melanocytes, reduces abnormal melanin synthesis; closes abnormal blood vessels, blocks the transport of inflammatory factors, and forms a virtuous cycle of "repair-stabilization".

Type-based treatment: epidermal melasma combined with low-energy 1064nm laser and chemical peeling; dermal or mixed type mainly uses 1064nm to avoid excessive peeling of the epidermis with short wavelengths.

Dynamic monitoring: Detect skin barrier function (TEWL, stratum corneum water content) before treatment. Those with obvious barrier damage (such as sensitive skin) need to repair for 1-2 weeks before treatment.

Cold compress and repair ingredients: Immediately after treatment, use physiological moisturizers (such as liposome dressings) containing ceramide, cholesterol, and fatty acids to replenish intercellular lipids and accelerate barrier repair; combined with topical anti-inflammatory ingredients such as asiatica glycoside and dipotassium glycyrrhizinate to reduce mild laser-induced inflammation.

Avoid superimposed stimulation: Acids (such as fruit acid, salicylic acid), retinoic acid, and high-concentration whitening agents are prohibited within 3-5 days after treatment to prevent the burden on the barrier.

Sequential repair: Use skin care products containing antioxidants (such as vitamin C, astaxanthin) during the intervals between laser treatments to reduce UV and laser-induced oxidative stress; take tranexamic acid (anti-fibrinolytic, anti-inflammatory) and glutathione (anti-oxidant) orally to synergistically inhibit melanin production from both inside and outside.

Microecological regulation: For patients with microbial imbalance, skin care products containing probiotics or prebiotics can be used to maintain the pH value and flora balance of the epidermis and reduce the risk of recurrence of inflammation.

PRECAUTIONS

Controversy and PrecautionsItems

Although low-energy 1064nm laser is relatively mild, its long-term impact on dermal elastic fibers and collagen still needs attention. Studies have shown that repeated thermal stimulation may accelerate the breakage of elastic fibers in photoaging areas, so the treatment cycle should be controlled at 3-6 times, and the skin repair status should be fully evaluated during the interval.

After 1064nm treatment, the skin's sensitivity to UV increases temporarily. If there is no strict sun protection (physical sun protection + SPF≥30/PA+++ chemical sun protection), UVB/UVA can further activate melanocytes by damaging the barrier, resulting in anti-blackening after treatment. Clinical observations show that the recurrence rate of pigmentation in patients who adhere to sun protection is reduced by 40%-60%.

SUMMARY

Summary

1064nm laser has become the core means of photoelectric treatment of melasma due to its deep penetration and low epidermal damage, but it is necessary to find a balance between "melanin fragmentation efficiency" and "barrier protection". In clinical practice, the principle of "low energy, long interval, and individualization" should be followed, laser treatment should be closely combined with barrier repair (physiological moisturizing, anti-oxidation, and microecological regulation), and sun protection should be emphasized throughout the process to maximize the efficacy and reduce the risk of recurrence. For patients with significantly damaged barrier function, it is recommended to start laser treatment after 2-4 weeks of basic repair (such as topical ceramide cream and oral vitamin E) to build a closed-loop management model of "repair-treatment-consolidation".

The core founding team of Suzhou Foremed Legend Medical Technology Co., Ltd. comes from well-known universities at home and abroad such as Peking University. Based on compliance and with product strength as the core, Foremed Legend focuses on the design, research and development, and application of high-end medical beauty optoelectronic equipment, and is committed to becoming a leading enterprise in the field of high-end medical beauty optoelectronic equipment, a provider of integrated intelligent solutions for diagnosis and treatment, and a pioneer of medical beauty data integration platform.

Through tackling a series of underlying key technologies, Foremed Legend has now independently developed a number of high-end medical devices, including picosecond laser therapy devices, long pulse laser therapy devices, intense pulsed light therapy devices, photoacoustic imaging skin detection devices, and cold air therapy devices, and continues to deepen the research and development of core product technologies, using better technical solutions to benefit the vast number of beauty seekers.

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