Treating Onychomycoses of the Toenail: Clinical Efficacy of the Sub-Millisecond 1,064 nm Nd: YAG Laser Using a 5 mm Spot Diameter
April 2012 | Volume 11 | Issue 4 | Journal Article | 496 | Copyright © April 2012
Utako Kimura MD,a Kaori Takeuchi MD,a Ayako Kinoshita MD,a Kenji Takamori MD PhD,a Masataro Hiruma MD PhD,b Yasushi Suga MD PhD a
aDepartment of Dermatology, Juntendo University Urayasu Hospital, Japan b Department of Dermatology, Juntendo University Nerima Hospital, Japan
Abstract
Background: Onychomycosis is a relatively common fungal infection. Current treatments have limited applicability and low cure rates.
Recently introduced laser therapy has shown to be a safe and effective treatment for onychomycosis. In this study, we evaluate a submillisecond Nd:YAG 1,064 nm laser for treating onychomycoses of the tonail.
Methods: Thirteen subjects (9 female, 4 male) with 37 affected toenails received 1 to 3 treatments 4 and/or 8 weeks apart with a
sub-millisecond 1,064 nm Nd:YAG laser. Diagnosis of onychomycosis was confirmed with microscopy. Average follow-up time was
16 weeks post-final treatment. Photos were taken and degree of turbidity was determined using a turbidity scale (ranging from "0 =
clear nail" to "10 = completely turbid nail") at each visit. Improvement in turbidity was determined by comparison of turbidity scores
at baseline and 16-week follow-up on average. Efficacy was assessed by an overall improvement scale (0 to 4), which combined improvement in turbidity scores and microscopic examination. Overall improvement was classified as "4 = complete clearance" if the
turbidity score indicated "0 = clear nail" accompanied by a negative microscopic result. No microscopic examination was performed
unless the turbidity score showed "0 = clear nail."
Results: Treatments were well tolerated by all subjects and there were no adverse events. Of the 37 toenails treated, 30 (81%) had
"moderate" to "complete" clearance average of 16 weeks post-final treatment. Nineteen toenails (51%) were completely clear and
all tested negative for fungal infection on direct microscopic analysis. Seven (19%) toenails had significant clearance and four (11%)
had moderate clearance.
Conclusions: The preliminary results of this study show this treatment modality is safe and effective for the treatment of onychomycosis
in the short term. Additional studies are needed to more fully assess the clinical and mycological benefits as well as optimize the treatment protocol and parameters.
J Drugs Dermatol. 2012;11(4):496-504.
INTRODUCTION
Onychomycosis is a relatively common fungal nail infec-tion that causes nail turbidity, trachyonychia, discoloration, and brittleness. Twelve milion individuals in
Japan are estimated to have tinea unguium.1 This is consistent
with the reported prevalence of onychomycosis in the United
States (US), which ranges from 14% 2 to 28% in persons over 60
years of age.3Although oral and topical antifungal medications
are currently the first line of treatment for onychomycosis,4 their
efficacy is limited. The efficacy of oral antifungals ranges from
14% to 50% 5,6 with the recurrence (relapse or reinfection) rate of
10% to 53%.5 On the other hand, the efficacy of topical medications is between 5.5% and 8.5% due to their inability to fully
penetrate the nail bed.7-12Alternative treatment options include
surgical avulsion of the infected toenail by clips or grinder,13
chemical avulsion by morpholine salicylate and uric acid, or a combination ointment.14 Surgical avulsion, while an alternative, has limited efficacy 15 and is rarely used as it causes undue
pain and may lead to post-operative complications, especially
in diabetic or immunocompromised patients.
The use of phototherapy for treating onychomycosis over the
past decades was first reported in the literature with the use
of a carbon dioxide (CO2) laser.16 Early studies with this CO2 laser report a 67% cure rate with a 22% recurrence rate at 6
months follow-up, with 22% of patients reporting mild pain
during the treatment.17This level of pain was considered acceptable as it was less than the pain experienced with other
more invasive treatment modalities.18However, the CO2 laser
energy was only absorbed at a shallow depth from the skin
surface, making it less effective for treating subungual mycotic
