Primary study on mechanism of long-pluse 1064nm Nd:YAG Laser treatment for onychomycosis

Keywords:medical fiber, laser fiber,  Time:20-08-2015

Objective:
The purpose of the basic study was to observe the effects of long-pulse 1064nm Nd:YAG laser irradiation on the growth and ultrastructure changes of 5 main pathogenic fungi of onychomycosis including Trichophyton rubrum, Trichophyton mentagrophytes, Candida albicans, Candida parapsilosis, Aspergillus fumigatus.And to compare drug sensitivity of some pathogenic fungi (e.g. C. albicans )before and after laser irradiation.
The purpose of the clinical part was to have an initial evaluation on the clinical efficacy, mycological clearance and safety of long pulse 1064nm Nd:YAG laser treatment for onychomycosis.

[Key words]:
onychomycosis;medical fiber; long pulse 1064nm Nd:YAG laser; therapy; dermatophytes,candida; nondermatophytes; ultrastructure; drug sensitivity

Methods:
To observe the effects of long-pulse 1064nm Nd:YAG laser irradiation on the growth of different pathogenic fungi, suspension of T. rubrum、T. mentagrophytes、C. albicans、C. parapsilosis were spotted on ager media. After incubation for several days, the colonies were exposed to various energies of 1064nm Nd:YAG laser. One untreated colony in each plate was left as the control. For T.r and T.m , diameters of colonies were measured on the first, third, and sixth days after laser irradiation. For C.a and C. p, the subculture’s survival rates of different energies of laser irradiation were assessed respectively.
As for A. fumigatus, having been incubated on the whole plate for one day,received various energies of Nd:YAG laser irradiation. One day after irradiation, the laser treated spots exhibited circular growth-free zones, which differed in size depending on the energy delivered. we compared the different diameters of circular growth-free zones after different energies of laser treatment.

Conclusion:
In vitro, when the energy of long pulse 1064nm Nd:YAG laser reaching a certain amount, the pathogenic fungi of onychomycosis could be inhibited significantly or be killed, and the ultrastructures of them also showed different degree of damagesaccordingly.