[Hinews] [Physician's Column] By Ara Bong, Director of Reset Clinic

The cornerstone of treating pigmentation disorders lies in a precise understanding of melanocytes. Melanin, concentrated at the epidermal-dermal junction, is stored in melanosomes—tiny organelles about 0.5 μm in size with a thermal relaxation time (TRT) of roughly 250 nanoseconds. To effectively target these minute structures without damaging surrounding tissue, laser pulse durations must be shorter than the TRT, meaning below 250 nanoseconds.

A leading tool in this domain is the Q-switched laser, which delivers high-energy pulses in nanoseconds, optimized for selective photothermolysis. This technology creates photoacoustic shock waves within melanocytes, breaking down pigment granules effectively. It has long been a mainstay in East Asia for treating conditions like melasma and Ota’s nevus.

Melasma is classified into epidermal and dermal types based on lesion depth, each requiring tailored energy levels and treatment approaches. For example, the Q-switched Nd:YAG laser, at low fluence levels of 4 J/cm² or less, is suited for targeting melanosomes at the subcellular level. In contrast, deeper dermal melasma requires higher fluence levels, above 4 J/cm², for effective treatment at the cellular level. Pre- and post-treatment care, including melanin suppression and extracellular matrix (ECM) optimization, is critical for success.
Beyond laser parameters, clinical outcomes hinge on identifying the correct endpoint. The most reliable indicator is “delayed perilesional erythema,” where redness around the lesion appears after a time lag, signaling an effective response. If the effect is insufficient, practitioners may aim for “immediate perilesional erythema” by adjusting treatment intensity.

Ara Bong, MD, Director of Reset Clinic
Ara Bong, MD, Director of Reset Clinic


Newer strategies, such as 'dual-toning,' combine Q-switched lasers with long-pulsed Nd:YAG lasers to address both epidermal pigment and dermal collagen and elastic fibers, thereby reducing recurrence rates.

In addition, adjunctive treatments such as needle radiofrequency (RF), which targets senescent fibroblasts, and skin boosters have shown promise in enhancing melasma outcomes.
The advent of picosecond lasers, with even shorter pulse durations, has opened new possibilities. These devices excel in tattoo removal and treating clustered melanocytes, offering hope for recalcitrant pigmentation disorders unresponsive to traditional Q-switched lasers. Ultimately, successful pigmentation treatment relies on a 'precision design' customized to each lesion’s characteristics and the patient’s skin condition.

In summary, effective pigmentation treatment requires a deep understanding of melanocyte biology, precise laser technologies like Q-switched and picosecond lasers, and customized approaches to optimize outcomes and minimize recurrence.

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