Laser therapies for onychomycosis – critical evaluation of methods and effectiveness

Abstract

The number of medical devices designed specifically to treat onychomycosis has recently increased, although their mechanism of action is not clear. We evaluated available laser therapies for onychomycosis by reviewing the existing literature. Twenty-two reports, published in peer-reviewed journals and as white papers out of 926 initial search results conveyed enough details to be included in this study. In most cases, the methodology of the trials described in the papers we reviewed was not comprehensive and the reporting of outcomes was not unified. We therefore found it hard to compare different clinical trials to one another. The majority of studies (81.82%) reported using an Nd:YAG laser device to treat onychomycosis. A total of 47.37% of the studies which used a 1064 device (and 47.83% of all studies we reviewed) reported that all treated patients responded positively to laser therapy. A total of 60% of studies reported achieving a complete cure (no clinical symptoms, nor negative mycology) in at least 50% of the treated patients. A low number of adverse events and their mild intensity were consistently reported across all studies, which makes this form of therapy particularly attractive to patients with contraindications for receiving systemic antifungal medication. In order to achieve more unified, comparable studies in the future, we suggest that researchers report a minimum set of outcome measurements: the calculation of the infected nail area pre- and posttreatment, as well as the number of patients achieving mycological, clinical and complete cures.

A critical review of improvement rates for laser therapy used to treat toenail onychomycosis

“…A substantial difference in mycological cure (culture and microscopy) was found when multiple nails per patient (60%) were used as opposed to one nail per patient (25%), suggesting that a possible overestimation of the antifungal abilities of lasers can occur. Perhaps, the use of the onychomycosis severity index (OSI) could be of assistance in future laser studies . The OSI is a classification system based on nail involvement, how distant the infection is from the matrix, presence of longitudinal streaks and/or thickening of the nail (greater than 2 mm) …”

“…short vs long‐pulsed, laser model) were not controlled in this review, applicability of this review is limited. Laser parameters can influence the amount of energy delivered to the fungal cells, altering their performance . Laser models such as the Nd:YAG elicit fungicidal effects by creating an accumulation of heat (43–51⁰C) in fungal mycelium .…”

“…Despite this limitation, the overall rates found within this review are comparable to rates found in other laser reviews. In a review conducted by Francuzike et al . #bib45.45% (10 of 22) of laser studies were reported to have an improvement in onychomycosis patients as evident in clinical outcome and/or mycological tests.…”

“…Perhaps, the use of the onychomycosis severity index (OSI) could be of assistance in future laser studies. 51 The OSI is a classification system based on nail involvement, how distant the infection is from the matrix, presence of longitudinal streaks and/or thickening of the nail (greater than 2 mm). 50 Comparatively, a recent review article has tabulated the frequency of medical endpoints as they relate to oral and topical therapy for the treatment of onychomycosis.…”

Acral manifestations of fungal infections

“…The Nd:YAG lasers were the first medical devices designed specifically for the treatment of onychomycosis, but the outcomes are still contradictory. 53 In one study, a temporary improvement in the appearance of the target nail was observed in 78% of patients and the affected area of the nail plate was reduced by at least 50% from the baseline in 46% of patients, 54 but another group found the 1064nm Nd:YAG laser was not an effective treatment for onychomycosis. 55 In two clinical trials .…”