Combination of 1064-nm Q-switched neodymium-doped yttrium-aluminum-garnet laser with Modified Jessner's peel for the treatment of Nevus of Ota: A case series of seven patients

Q-switched 1064 nm Nd: YAG laser restores skin photoageing by activating autophagy by TGFβ1 and ITGB1

Excessive ultraviolet B ray (UVB) exposure to sunlight results in skin photoageing. Our previous research showed that a Q-switched 1064 nm Nd: YAG laser can alleviate skin barrier damage through miR-24-3p. However, the role of autophagy in the laser treatment of skin photoageing is still unclear. This study aims to investigate whether autophagy is involved in the mechanism of Q-switched 1064 nm Nd: YAG in the treatment of skin ageing. In vitro, primary human dermal fibroblast (HDF) cells were irradiated with different doses of UVB to establish a cell model of skin photoageing. In vivo, SKH-1 hairless mice were irradiated with UVB to establish a skin photoageing mouse model and irradiated with laser. The oxidative stress and autophagy levels were detected by western blot, immunofluorescence and flow cytometer. String was used to predict the interaction protein of TGF-β1, and CO-IP and GST-pull down were used to detect the binding relationship between TGFβ1 and ITGB1. In vitro, UVB irradiation reduced HDF cell viability, arrested cell cycle, induced cell senescence and oxidative stress compared with the control group. Laser treatment reversed cell viability, senescence and oxidative stress induced by UVB irradiation and activated autophagy. Autophagy agonists or inhibitors can enhance or attenuate the changes induced by laser treatment, respectively. In vivo, UVB irradiation caused hyperkeratosis, dermis destruction, collagen fibres reduction, increased cellular senescence and activation of oxidative stress in hairless mice. Laser treatment thinned the stratum corneum of skin tissue, increased collagen synthesis and autophagy in the dermis, and decreased the level of oxidative stress. Autophagy agonist rapamycin and autophagy inhibitor 3-methyladenine (3-MA) can enhance or attenuate the effects of laser treatment on the skin, respectively. Also, we identified a direct interaction between TGFB1 and ITGB1 and participated in laser irradiation-activated autophagy, thereby inhibiting UVB-mediated oxidative stress further reducing skin ageing. Q-switched 1064 nm Nd: YAG laser treatment inhibited UVB-induced oxidative stress and restored skin photoageing by activating autophagy, and TGFβ1 and ITGB1 directly incorporated and participated in this process.

Disorders of Facial Hyperpigmentation

Disorders of hyperpigmentation are common and challenging conditions which can arise due to a myriad of etiologic factors. Many of them can present across skin types but are more common in skin of color individuals with Fitzpatrick skin types III-VI. Facial hyperpigmentation, in particular, can have a significant impact on the quality of life of affected individuals due to its increased visibility. This article provides a comprehensive review of disorders of facial hyperpigmentation including epidemiology, pathogenesis, diagnostic considerations, and treatment approaches for these conditions.

Aiming to personalized laser therapy for nevus of Ota: melanin distribution dependent parameter optimization

Aiming to the personalized laser therapy of nevus of Ota (NO), a local thermal non-equilibrium model was employed to optimize laser wavelength, pulse duration, and energy density under different melanin depth and volume fraction. According to our simulation, the optimal pulse duration is between 15 and 150 ns to limit heat transfer inside the hyperplastic melanin, and 50 ns is recommended to decrease the energy absorption by normal melanin in epidermis. Correlations of the minimum and the maximum energy densities are proposed with respect to melanin depth and volume fraction for the 755-nm and 1064-nm lasers. For the same NO type, the therapy window of the 755-nm laser is larger than that of 1064-nm. For NO with shallow depth or low volume fraction, the 755-nm laser is recommended to make the treatment more stable owing to its lager therapy window. For deeper depth or higher volume fraction, the 1064-nm laser is recommended to avoid thermal damage of epidermis. Through comparison with clinical data, the optimized laser parameters are proved practicable since high cure rate can be achieved when energy density falls into the range of predicted therapy window. With developing of non-invasive measurement technology of melanin content and distribution, personalized treatment of NO maybe possible in the near future.

Treatment of nevus of Ota with 1064 nm picosecond Nd:YAG laser: A retrospective study

Nevus of Ota has been successfully treated by lasers. Currently, 1064 nm picosecond Nd:YAG lasers have become available for the treatment of pigmented disorders. However, there are few studies concerning the application of 1064 nm picosecond Nd:YAG laser in nevus of Ota. This study aimed to evaluate the efficacy and safety of a 1064 nm picosecond Nd:YAG laser for the treatment of nevus of Ota. We conducted a retrospective analysis of Chinese patients with nevus of Ota who had been treated with a 1064 nm picosecond Nd:YAG laser. Those who had any other laser treatment during the period of picosecond laser treatment were excluded. Via a visual analog scale for percentage of pigmentary clearance in standard photographs, the treatment efficacy was assessed by three blinded physician evaluators. A total of 16 subjects were included in this retrospective study. The average age at the beginning of treatment was 16.87 years old (range of 4 months to 59 years), and all patients were of Fitzpatrick skin type IV. Total treatment ranged from 1 to 5 sessions. A 1064 nm picosecond Nd:YAG laser with a mean fluence of 1.8-4.3 J/cm² was used at 3-12 month intervals. The mean efficacy score for all 16 patients was 2.56 after one session, and the mean efficacy score of 13 patients who completed two sessions and nine patients who completed three sessions were 3.15 and 3.51, respectively. Postinflammatory hyperpigmentation after treatment was only observed in 1 (1/16, 6.25%) patient. The 1064 nm picosecond Nd:YAG laser is an effective and safe approach for treating nevus of Ota.