Dr. Hong Won-Gyu discusses Hironic’s picosecond laser that can be used to treat scars, wrinkles and pores using its laser-induced optical breakdown (LIOB) system 

The release of picosecond-domain lasers featuring a picosecond pulse duration in the market began several years ago. While nanosecond-domain lasers are only used for pigment treatment, picosecond-domain lasers are used in a wider range of treatment categories, including the treatment of scars, wrinkles, and pores as well as a pigment treatment, by using the mechanism of laser-induced optical breakdown (LIOB). 

The PICOHI system of Hironic stably implements a 300 ps pulse duration. With picosecond lasers, the shorter the pulse duration, the more the advantages. The SRT (stress relaxation time) of a melanosome with a diameter of 1 μm is 333 ps. Accordingly, an acoustic shock wave is only confined within the melanosome when a picosecond laser beam with a pulse duration below 333 ps is irradiated, so as to allow treatment of pigment lesions with less adverse effects. 

Figure 1 image of a scratch scar (A) before and (B) after treatment using the ZMLA handpiece 5 mm, 1.3 J/cm2 stacking  

Treatment of pigment lesions using the 532 nm wavelength of the conventional laser causes PIH frequently. The PICOHI system of Hironic stably implements 300 ps, and minimises damages and adverse effects that occur during conventional nanosecond-domain treatment. 

A fractional handpiece is indispensable in the treatment of pores, scars or wrinkles. Most of the previously released picosecond laser systems come with either MLA or DOE handpieces. The PICOHI system is advantageous because it is compatible with a wider variety of MLA and DOE handpieces. The MLA handpiece causes Laser Induced Optical Breakdown (LIOB) inside tissues. Micro dots cause LIOB inside skin to regenerate skin and reduce scars.

The PICOHI system comes with two types of MLA handpieces: VLMA and ZMLA. With the VMLA handpiece, a variety of layers inside skin can be treated by adjusting the focus depth by 0.5 mm. With the ZMLA handpiece which can change the spot size in the 4 to 12 mm range, small or large scars can easily be treated through simple control of the handpiece. 

Figure 2 Image of LIOB biopsy

The PICOHI system also comes with a DOE handpiece with two types of wavelengths: 1064 nm and 532 nm. DOE laser skin toning using a low energy with a wavelength of 1064 nm can treat skin texture or pore issues, without interfering with everyday activities. The 532 DOE is effective in curing pigment lesions or superficial scars through several repeated treatment sessions.

The 650 Dye handpiece, also supplied with the PICOHI system, helps remove dermal pigment legions or colour tattoos. Tattoos with many colours, which are difficult to remove using conventional laser systems. 

The RMS feature connects a laser system to WiFi or Internet to check for a problem through diagnosis of the system and informs the system operator and manufacturer of the risk of a problem in advance. The feature is advantageous because you can be informed of a system problem and have it corrected through warranty service in advance. 

The PICOHI system will surely play a central role in a wide variety of treatment categories, ranging from treatment of intractable pigment to treatment of tattoos, pores and scars. 

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