Formation of new melasma lesions in the periorbital area following High-fluence, 1064-nm, Q-switched Nd/YAG laser

Q-Switched Laser Combined with Intense Pulsed Laser in the Treatment of Melasma Based on Reflection Confocal Microscope

Chloasma is a prevalent clinical hyperpigmentation skin disorder that causes symmetrical brown to tan patches on the cheeks, as well as the neck and forearms on rare occasions. The pathophysiology of this condition is complicated, and there is now no cure. Under the light microscope, the full-thickness melanin of the epidermis in the skin lesions was increased, and the dermal chromophages increased. At present, the treatment of melasma mainly includes topical drugs, chemical peels, systemic drugs, laser therapy, and traditional Chinese medicine. With the development of medical technology, intense pulsed light and Q-switched laser have been widely used in the treatment of melasma, which can emit laser beams to penetrate the dermis uniformly to treat deep pigmented lesions in the dermis. After a stable treatment outcome for melasma is achieved, it is important to minimize side effects such as postinflammatory hyperpigmentation and skin irritation. Therefore, this paper uses a reflection confocal microscope to establish an evaluation index system and then uses a neural network to evaluate the treatment effect. The work of this paper is as follows: (1) this paper introduces various methods of treating melasma at home and abroad and focuses on the application of intense pulsed light therapy and low-energy Q-switched Nd: YAG laser in the treatment of melasma. (2) In this paper, the case data samples are trained with the designed BP network to obtain a reliable evaluation network model. (3) The results and mistakes of the evaluation are produced by training the genetic algorithm optimized backpropagation (GA-BP) network structure model to evaluate the treatment effect of chloasma. Finally, it has been demonstrated that the GA-BP network has great accuracy and stability.

Skin diseases in Asian individuals that you do not want to miss: A selection of unique or relatively more common conditions in Asian populations

The Asian population currently constitutes a simple majority of the global population, comprising nearly 60%. The percentage of the US population that identifies as Asian is expected to grow to 41 million by the year 2050, making up an eventual 9% of the US population. As the world and US populations of Asian individuals increase, the demand for dermatologic care from this population will increase, requiring dermatologists to become more familiar with the diagnosis and treatment of Asian-specific skin characteristics and diseases. In this contribution, we review skin conditions specific to or relatively more common in Asian patients to help recognition and management of diseases in an increasing Asian patient population. We discuss prurigo pigmentosa, primary cutaneous plasmacytosis, lipodystrophia centrifugalis abdominalis infantilis, Epstein-Barr viru-positive T- and natural killer-cell lymphoproliferative disorders, acquired bilateral nevus of Ota-like macules, and Behҫet disease.

Clinical improvement of photoaging-associated facial hyperpigmentation in Korean skin with a picosecond 1064-nm neodymium-doped yttrium aluminum garnet laser

Traditional attempts at alleviating photoaging-associated facial pigmentation conditions such as melasma, mottled hyperpigmentation, and post-inflammatory hyperpigmentation have yielded disfiguring cosmetic results. Laser toning using a low-fluence Q-switched 1064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser has been more commonly applied to date. However, the treatment efficacy and safety of this approach have not been widely reported. This study therefore evaluated the efficacy and safety of picosecond 1064-nm Nd:YAG laser application for photoaging-associated facial pigmentation treatment in Korean subjects. Forty-seven Korean subjects with photoaging-associated facial pigmentation underwent picosecond 1064-nm laser application. The clinical improvement of 17 patients was assessed by objective measurements such as melanin and erythema indices. All subjects received six biweekly treatments with the laser in a three-pass fashion delivering approximately 2000 to 2500 shots using a zoom handpiece with a spot size of 7 mm, fluence ranging from 0.4 to 0.7 J/cm², and a repetition rate of 10 Hz. Clinicians evaluated the improvement of pigmentation using the pigmentation area and severity index (PSI), and subjects reported their satisfaction level on a four-point scale. Statistical analyses were performed using the SPSS version 19.0 for Windows software program (IBM Corp., Armonk, NY, USA). Forty-seven subjects (45 females and two males) completed this study with a 12-week follow-up period. The average decrease in PSI value at 12 weeks after treatment was 6.85 ± 6.35 points (p < 0.001). The average decreases in the values of the erythema and melanin indices were 19.41 ± 64.64 points (p = 0.234) and 28.88 ± 32.89 points (p = 0.002). An analysis of 32 subjects' reports (68.1%) suggested good or excellent improvement. No serious adverse effects were observed during treatment or the follow-up period. Picosecond 1064-nm Nd:YAG laser application appears to be safe and effective in improving various photoaging-associated facial pigmentation conditions in Korean skin.

Periorbital melasma: Hierarchical cluster analysis of clinical features in Asian patients

BACKGROUND

Studies have shown melasma lesions to be distributed across the face in centrofacial, malar, and mandibular patterns. Meanwhile, however, melasma lesions of the periorbital area have yet to be thoroughly described.

METHODS

We analyzed normal and ultraviolet light-exposed photographs of patients with melasma. The periorbital melasma lesions were measured according to anatomical reference points and a hierarchical cluster analysis was performed.

RESULTS

The periorbital melasma lesions showed clinical features of fine and homogenous melasma pigmentation, involving both the upper and lower eyelids that extended to other anatomical sites with a darker and coarser appearance. The hierarchical cluster analysis indicated that patients with periorbital melasma can be categorized into two clusters according to the surface anatomy of the face. Significant differences between cluster 1 and cluster 2 were found in lateral distance and inferolateral distance, but not in medial distance and superior distance. Comparing the two clusters, patients in cluster 2 were found to be significantly older and more commonly accompanied by melasma lesions of the temple and medial cheek.

CONCLUSION

Our hierarchical cluster analysis of periorbital melasma lesions demonstrated that Asian patients with periorbital melasma can be categorized into two clusters according to the surface anatomy of the face.

Retreatment using a dual mode of low-fluence Q-switched and long-pulse Nd:YAG laser in patients with melasma aggravation after previous therapy

BACKGROUND

Aggravated melasma after treatment is vulnerable to stimulation, can easily deteriorate, and may be distressing without proper management.

OBJECTIVE

To retrospectively assess the effectiveness and safety of combination therapy using low-fluence Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) laser (QSNY) and long-pulse Nd:YAG laser (LPNY) (dual toning) in patients with rebound melasma.

MATERIALS AND METHODS

A total of 30 patients with aggravated melasma after previous therapy who were treated with dual toning were enrolled. A total of 10 sessions were conducted at 1-week intervals, followed by maintenance treatment. The results were evaluated using the modified Melasma Area and Severity Index (mMASI) and the physician's global assessment (PGA) before and 2 months after completing the 10 treatment sessions.

RESULTS

The baseline mMASI was 10.48 ± 3.64, which significantly decreased to 3.22 ± 1.45 2 months after completing the 10 treatment sessions (p < 0.001). Twenty-four patients (80%) had PGA grade 4 (76-100% improvement) and 6 patients (20%) had PGA grade 3 (51-75% improvement).

CONCLUSION

Dual toning may be a safe and effective salvage treatment for patients with aggravated melasma after previous treatment. LPNY may stabilize melasma activity to prevent rebound hyperpigmentation via dermal remodeling.