For this study, the case definition of onychomycosis included moderate to severe distal subungual onychomycosis including subjects with evidence of subungual dermatophytoma or yellow spikes, lateral and proximal onychomycosis and severely dystrophic nail plates. Subjects with only superficial white onychomycosis were excluded. Confirmation of the clinical diagnosis of onychomycosis of at least one great toenail included a positive KOH wet mount.