The successful treatment of melasma is one of the hot issues in the field of dermatology. However, the pathogenesis of melasma has not yet been clearly understood. Kang et al.13
demonstrated that epidermal hyperpigmentation, possibly caused by both an increased number of melanocytes and an increased activity of melanogenic enzymes overlying dermal changes, were caused by solar radiation. Increased vascularity is also one of the major findings in melasma14
. Considering these histopathological findings in melasma, the ideal treatment could be achieved by targeting these several issuing components. From this point of view, IPL was considered as a very promising treatment modality. The previous studies on IPL in melasma patients usually showed good to excellent results6,15
In the meticulous reading of the previous studies of IPL or other lasers on melasma patients, the most worrisome hyperpigmentation started to be noticed, 2 to 4 weeks after the treatment. This is also very compatible with the clinical experiences in the treatment, especially the mixed type melasma. After the IPL irradiation, the distribution of melanosomes is drastically changed. Melanin cap structures, in which the melanosomes are dispersed within the basal keratinocytes collapse and melanosome accumulation as the intraepidermal microcrust (IEMC), gradually desquamates from the skin by 5 to 7 days16
. Afterwards, it appears that the melanosomes are replenished and melanocytes are reactivated to produce melanin pigment in patients who showed hyperpigmentation after the treatment. The survived melanocytes and melanosomes get back in their cycle, resulting in pigment transfer to the epidermis and dermis4,9,16
. Therefore, we treated the patients first with IPL, and after two weeks, the patients were led into a successive weekly exposure to low fluence QS Nd:YAG laser in order to deplete the survived melanosomes and inactivate melanocytes. After one time of IPL, EI and MI significantly decreased (data not shown). This might be explained by the IEMC phenomenon, which appears to be the most prominent in the first session of IPL in almost all patients16
. After 6 weeks, patients showed 26.10% (174.08±64.32 to 128.65±41.36, ) reduction of melanin index, and 59.35% decrease of the modified MASI scores. Accordingly, we thought that the maintenance of the relatively rapid and significant improvement, after the irradiation of IPL and further improvement could be obtained by several times of QS Nd:YAG laser.
Recently, so-called "laser toning" that uses collimated low-fluence 1,064 nm QS Nd:YAG laser has gained popularity for the treatment of melasma in Eastern Asia. The repetitive treatments of QS Nd:YAG laser of the fluence was just enough to damage the melanosomes subcellularly, which can induce excellent clinical results without the high risk of rebounding hyperpigmentation17,18
. The QS Nd:YAG laser treatment may also produce nonspecific dermal wound and induce inflammation, facilitating a migration of melanophages4,8,17
. There was no epidermal disruption when low fluence of the laser was used. However, the inflammation may cause increased epidermal turnover, which can remove the up dispersed melanin pigment in the epidermal keratinocytes.
Overall, several studies have demonstrated that several weekly treatments, with the 1,064 nm QS-Nd:YAG laser at sub-threshold photothermolytic fluences (<5 J/cm2
), show relatively high efficacy and less side effects, like the hypo- or hyperpigmentation3,4,9
The drawbacks of QS Nd:YAG laser applications in melasma patients can be listed below. Relatively long period of treatment is required and weekly repetitive treatments can be a burden to patients, and it might exhaust the melanosomes completely out, which shows clinically the confetti-like hypopigmentation10,11
. Moreover, this treatment doesn't have any downtime or pain, which can make some patients very addictive to the treatment. Chan et al.10
reported case series of facial depigmentation, associated with low fluence QS Nd:YAG laser, and they pointed out the risk of possible occurrence of punctuate leukoderma, which is not cosmetically acceptable. However, the complications might have not occurred if they had treated the patients with longer off-treatment period and lower energy. Although the adverse effects can be avoided, we have to consider the possibility of these unwanted outcomes.
The combinational treatment with IPL and QS Nd:YAG laser can induce clinical improvement, which means that it does not need multiple weekly exposures (more than 10 times in practice generally) of QS Nd:YAG laser, and it may lower the risk of rebound hyperpigmentation, after IPL alone. We analyzed the correlation MI and EI changes between the before and after IPL, and total MI and EI changes between the baseline and after all sessions to evaluate the effects of IPL treatment in this study. It is worthy to mention that the strong positive correlations between the MI changes before and after IPL, as well as the total MI changes after all sessions were observed. Swift removal of epidermal pigments, using IPL and suppression of reactivating melanosomes with subsequent low fluence QS Nd:YAG laser, enables only 5 treatment sessions to produce significant clinical results. Moreover, 60% of patients involved in the study did not show any clinical aggravation, during the follow-up periods (average 5.9 months) without further medical treatments.
Most previous studies used QS-Nd:YAG laser at 3.0 to 4.0 J/cm2
. There were side effects, such as punctate leucoderma and postinflammatory hypopigmentation in those reports10,11
. These adverse events did not occur in our patients. It might be because we used lower fluence of 2.0 to 2.5 J/cm2
than the ones used in the previous studies.
This study has limitations in that it was a retrospective chart review of the treatments, and there was no control group. Longer follow-ups were available for 12 out of the 20 patients, and those were the patients who were satisfied with the initial results, which can be an element of bias. However, the 5 treatment sessions can induce the substantial clinical results without any side effects or recurrences during the treatment free periods (mean 5.9 months) in 60% of the patients, and thus, it can be cautiously said that IPL and subsequent QS Nd:YAG laser therapy work beautifully on the melasma patients with less treatment sessions, and without serious side effects.
In this study, we first reported the combinational treatment of IPL and QS Nd:YAG laser for the treatment of mixed type melasma. It could improve both epidermal and dermal pigmentation and vascular component with fewer treatment sessions to reach acceptable clinical outcomes.
Therefore, the combination of IPL and QS Nd:YAG laser may be a good therapeutic option in the treatment, especially, of the mixed type melasma.