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

Onychomycosis is a nail infection that is primary caused by dermatophytes. Alternative treatments are needed as current therapies (oral and topical antifungals) have limited effectiveness. Lasers are currently approved by the FDA to temporarily increase the amount of clear nail in onychomycosis patients. Lasers can theoretically elicit fungicidal effects but in practice produce mixed results. This review compared laser-induced improvement rates to FDA-approved indications and traditional onychomycosis treatments. A review of the literature (PubMed, Clinicaltrials.gov, Medline and Embase) was used to locate articles for this review. RCTs, non-randomized, uncontrolled and retrospective studies that included at least one of the following measures were eligible; complete cure, mycological cure, clinical improvement and clinical cure. Mycological cure (negative culture and negative microscopy) was evaluated in two studies using patients as the unit of analysis with an average rate of 11%, increasing to 63% when nails were used as the unit of analysis (three studies). Clinical cure (100% clear nail) was evaluated in six studies with a rate of 13% using nails as the unit of analysis and 13% when patients were used as the unit of analysis (two studies). Clinical improvement (at any time point) was found in 36% of patients (five studies) and 67% of nails (nine studies). Nail clarity as measured by clear nail growth and/or nail plate/bed clearance at 12 weeks was found to be 2.6 mm across onychomycotic nails. Laser studies, to date, provide preliminary evidence of clinical improvement and clear nail growth in toenail onychomycosis, consistent with the FDA clearance for aesthetic endpoints. Laser studies however do not provide efficacy rates for medical endpoints that equate or exceed those found with traditional therapies (oral and topical treatments).