Harnessing nd: YAG laser technology to combat antifungal resistance in yeast-driven onychomycosis

Onychomycosis is a persistent nail infection often caused by dermatophytes or yeasts, with conventional treatments limited by long durations, poor compliance, and resistance. The long-pulsed Nd: YAG 1064 nm laser (NDYL) has emerged as a potential adjunct; however, its effects in combination with antifungals against yeast-related cases are unclear. This study examined the in vitro synergistic effect of NDYL with four antifungal agents-Ketoconazole (KET), Itraconazole (ITK), Voriconazole (VRC), and Terbinafine(TRB)-on clinical yeasts isolates from patients with onychomycosis. Yeast isolates were identified through ITS PCR sequencing. Susceptibility testing was conducted using the CLSI disk diffusion method (document M44-A2). Two experimental series-vital nail scrapings and cultured colonies-were exposed to standardized NDYL laser parameters. Antifungal activity was assessed by measuring inhibition zone diameters, and statistical comparisons were performed using paired t-tests. NDYL significantly enhanced antifungal activity, with the most pronounced effects observed for KET and ITC (p < 0.05). KET achieved up to 100% sensitivity improvement in nail scraping samples. VRC and TRB demonstrated moderate but consistent enhancements. Recorded irradiation temperatures remained below 42 °C, suggesting primarily non-thermal mechanisms. The relative frequencies of increased inhibition zone diameters in nail scrapings, yeast colonies, and combined datasets were: ITC (83.3%, 50.0%, 66.7%), VRC (66.7%, 50.0%, 58.3%), TRB (33.3%, 16.7%, 25.0%), and KET (100%, 66.7%, 83.3%). These findings support NDYL as a potential adjunctive tool for enhancing antifungal efficacy in yeast-associated onychomycosis. Further in vivo research is warranted to confirm clinical applicability and refine treatment protocols.