Treatment of onychomycosis using a submillisecond 1064-nm neodymium:yttrium-aluminum-garnet laser

Abstract

Background: Laser treatment has emerged as a novel treatment modality for onychomycosis.

Objective: We sought to determine thermal response and optical effects of a submillisecond neodymium:yttrium-aluminum-garnet (Nd:YAG) 1064-nm laser on common fungal nail pathogens, and the clinical efficacy and safety of the Nd:YAG 1064-nm laser on onychomycotic toenails.

Methods: A 4-part in vitro and in vivo study was conducted using a Nd:YAG 1064-nm laser. The first portion evaluated 3 different nail pathogens in suspension at 7 heat and time exposures. The second and third parts of the study irradiated pure fungal colonies. The final portion involved an in vivo treatment of toenails over 5 treatment sessions.

Results: A fungicidal effect for Trichophyton rubrum was seen at 50°C after 15 minutes, and for Epidermophyton floccosum at 50°C after 10 minutes. Limited growth of Scytalidium was seen at 55°C after 5 minutes. No inhibition was observed after laser treatment of fungal colonies or suspensions. In vivo treatment of toenails showed no improvement in Onychomycosis Severity Index score.

Limitations: The Nd:YAG 1064-nm laser was the only laser tested.

Conclusions: Laser treatment of onychomycosis was not related to thermal damage or direct laser effects. In vivo treatment did not result in onychomycosis cure.

Keywords: CFU; Nd:YAG; OSI; Onychomycosis Severity Index; colony-forming unit; fungal; irradiation; laser; neodymium:yttrium-aluminum-garnet; onychomycosis; thermal.