Morphologic Changes of Zebrafish Melanophore after Intense Pulsed Light and Q-Switched Nd:YAG Laser Irradiation = Morphologic Changes of Zebrafish Melanophore after Intense Pulsed Light and Q-Switched Nd:YAG Laser Irradiation

다국어 초록 (Multilingual Abstract)

Background: Recently, the pulse-in-pulse mode of intense pulsed light (IPL) has been used increasingly for the treatment of melasma. Objective: To observe the morphologic changes in the melanophore in adult zebrafish after irradiation with conventional and pulse-in-pulse IPL and Q-switched Nd:YAG (QSNY) laser. Methods: Adult zebrafish were irradiated with conventional and pulse-in-pulse mode of IPL. The conditions for conventional IPL were 3 mJ/cm², 560 nm filter, and pulse widths of 7, 20, and 35 msec. The pulse-in-pulse conditions were 3 mJ/cm² and on-time 1/off-time 2. The QSNY laser was used with the settings of 1,064 nm, 0.4 J/cm², a 7 mm spot size, and one shot. Specimens were observed using a light microscope, a transmission electron microscope (TEM), a scanning electron microscope (SEM) and a confocal micro-scope. Results: After conventional IPL irradiation with a 7 msec pulse width, melanophore breakage was observed us-ing light microscopy. Under TEM, irradiation with conven-tional IPL for 7 msec and pulse-in-pulse IPL induced melano-phore thermolysis with vacuolization. However, changes in the melanophore were not observed with 35 msec IPL. Under SEM, unlike the control and QSNY groups, IPL-irradi-ated zebrafish showed finger-like fusion in the protein struc- ture of scales. Specimens examined by a confocal micro-scope after conventional IPL irradiation showed a larger green-stained area on TUNEL staining than that after pulse-in-pulse mode IPL irradiation. Conclusion: Zebrafish irradiated with long pulse-IPL showed no morphologic changes using light microscopy, while morphological changes in melanophores were evident with use of TEM. Pulse-in-pulse mode IPL caused less damage than conven-tional IPL. (Ann Dermatol 28(6) 711∼717, 2016)