Onychomycosis is a chronic fungal infection of the nail plate, nail matrix, and nail bed that is more common in the toenails. The prevalence of onychomycosis is 2–13% [
For this study, 22 patients (18 to 76 years old) with clinically and mycologically (both direct microscopy and cultures) diagnosed onychomycosis for at least one year were enrolled in the Department of Dermatology at Beijing Friendship Hospital. The Scoring Clinical Index of Onychomycosis (SCIO) [
Patients were treated with a long-pulsed Nd:YAG 1064-nm laser (Dualis SP; Fotona, Slovenia). The device fluency was set at 35–40 J/cm2, with a pulse duration of 35 ms, spot size of 4 mm, and frequency of 1.0 Hz. The fluency was chosen based on nail thickness, since thicker nails would require higher fluency. Each infected nail was treated with laser beam irradiation on the full nail plate and nail fold, using a spiral pattern that was repeated for 3 passes, with 2-min pause between passes. The two-stage laser treatment design for our study (Figure
Two-stage treatment procedure. The entire procedure lasted 24 weeks.
Direct microscopy, culture and clinical assessment were performed at 4, 8, 12, 16, 20, 24, and 36 weeks. The mycological efficacy was evaluated by the rate of simultaneous negative direct microscopy and negative cultures. Clinical efficacy was divided into four categories: cure (complete new nail growth with a smooth and brightly colored nail plate and less than 5% defects), significant improvement (≥ 60% new nail growth), improvement (≥ 20 and < 60% new nail growth), and inefficiency (< 20% new nail growth). The clinical efficacy rate is equal to the cure rate plus the significant improvement rate [
Patients were asked to report all adverse events directly during each laser treatment. A five-point Verbal Rating Scale (VRS; 0 = no pain, 1 = mild pain, 2 = moderate pain, 3 = severe pain, and 4 = intolerable pain) was used to evaluate pain. Patients were asked to mark the word (one of five that were given) that best fit the pain intensity during the laser treatment.
An
A total of 100 affected nails (88 toenails and 12 fingernails) from 22 patients (8 males and 14 females) were included, of which 37% were the nail of the big toe. The average age was 49.6 years (range from 27 to 76 years), and only three patients were older than 60 years. These patients exhibited all four clinical types of onychomycosis: distal and lateral subungual onychomycosis (DLSO), superficial white onychomycosis (SWO), proximal subungual onychomycosis (PSO), and total dystrophic onychomycosis (TDO) (Table
Nail characteristics.
N (%) | ||
---|---|---|
Clinical type | DLSO | 87 (87%) |
SWO | 3 (3%) | |
PSO | 2 (2%) | |
TPO | 2 (2%) | |
SCIO grade | II | 17 (17%) |
III | 55 (55%) | |
IV | 28 (28%) | |
Hyperkeratosis | < 1 mm | 35 (35%) |
1–2 mm | 44 (44%) | |
> 2 mm | 21 (21%) |
DLSO: distal and lateral subungual onychomycosis, SWO: superficial white onychomycosis, PSO: proximal subungual onychomycosis, and TDO: total dystrophic onychomycosis.
Two-stage laser treatment significantly improved the mycological cure rate (negative direct microscopy and negative culture, Figure
(a) Mycological cure rate and (b) clinical efficacy rate of nails that received laser treatment. There was a significant improvement in both rates at week 24, compared to week 8.
(a) Mycological cure rate of SCIO II, SCIO III, and SCIO IV during laser treatment.
The clinical efficacy significantly improved after two-stage laser treatment (Figure
All patients reported various intensities of pain using the VRS. Most patients reported moderate pain, while none reported intolerable pain. All patients with mild pain (3 out of 3) were mycologically cured at week 36, whereas 8 out of 12 with moderate pain and 4 out of 7 with severe pain experienced mycological cures (Table
Pain measurement and number of mycologically cured cases at week 36.
Pain level | Number of patients | Number of mycological cures |
---|---|---|
no pain (0) | 0 | 0 |
mild pain (1) | 3 | 3 (100%) |
moderate pain (2) | 12 | 8 (66.7%) |
severe pain (3) | 7 | 4 (57.1%) |
intolerable pain (4) | 0 | 0 |
The mycological cure rate was characterized by the degree of hyperkeratosis. Nails with fungal eradication and hyperkeratosis of less than 1 mm displayed the best outcomes after laser treatment, with effects starting to appear at week 4, whereas those with hyperkeratosis of 1–2 mm or greater than 2 mm saw effects around week 8. The overall outcomes for nails with hyperkeratosis of less than 1 mm exhibited significantly better effects than those with hyperkeratosis of 1–2 mm or greater than 2 mm at week 20, week 24, and week 36 (Figure
Mycological cure rate of hyperkeratosis from weeks 4 to week 36. The overall outcomes of hyperkeratosis of less than 1 mm exhibited significant (
Nail appearances was also evaluated during the procedure. Laser sessions significantly improved cosmetic appearance at week 24 and week 36 (Figure
Representative photographs of the nails before and after laser treatment from two patients. Patient 1: (a) pretreatment, (b) week 8, (c) week 24, and (d) week 36. Patient 2: (e) pretreatment, (f) week 8, (g) week 24, and (h) week 36.
The clinical treatment of onychomycosis remains extremely challenging due to the high recurrence rate. In general, current clinical interventions include oral, topical, and surgical therapies [
Recently, the Nd:YAG 1064-nm laser was reported to inhibit the
We designed the long-pulsed Nd:YAG 1064-nm laser (Fotona) with the following parameters: 35–40 J/cm2, a pulse duration of 35 ms, a spot size of 4 mm, and a frequency 1.0 Hz. The mycological cure rate and the clinical efficacy rate of the nails were 29% and 21% at week 8 (first stage of treatment), 69% and 35% at week 24 (second stage of treatment), and 67% and 39% at week 36, respectively. The peak mycological efficacy rate occurred at week 24 and was stable until week 36, suggesting the laser therapy was effective. The peak clinical efficacy rate also occurred at week 24 and continued to increase through week 36. Long-term follow-up will be needed to determine the clinical recurrence time after laser treatment. Compared to other studies, the severity of onychomycosis, treatment course, treatment interval, parameters of the laser, evaluation criteria, and follow-up time varied, which may contribute to the efficacy of laser treatment. Therefore, randomized, intense follow-up clinical studies, including standard treatments and standard evaluation methods, will be conducted in the future to fully elucidate the efficacy of laser therapy on onychomycosis.
Our study demonstrated that efficacy significantly improved after the second stage of treatment compared to the first stage, suggesting that the second phase was necessary. Compared to other studies with only 8 sessions of laser treatment (one-stage), our study with 12 sessions laser treatment (two-stage) had better mycological efficacy rates. Lu [
The efficacy of laser treatment also correlated with SCIO grade. Efficacy trend lines revealed that SCIO II was better than SCIO III, that SCIO III was better than SCIO IV, and that there was a significant difference between SCIO II and SCIO IV. Sergeev et al. [
Regarding the degree of hyperkeratosis, we found that nails with hyperkeratosis of less than 1 mm had better outcomes. If nails thicker than 1 mm are treated with 40% urea before laser treatment, it could improve the overall efficacy.
In total, 84 nails from 19 patients were infected by
All patients experienced mild to severe pain during laser treatment, and thus, patients with high pain tolerance had better laser treatment efficacy. Laser therapy uses heat energy, which is the reason why the pain tolerant patients saw better outcomes. The question of whether it is necessary to use cooling device or anesthesia before laser treatment to get better effects is difficult to answer. Cooling devices or anesthesia may help patients to withstand the pain associated with treatment, so as to improve the laser effect, but there have been reports of nail loss as a result of overheating [
In conclusion, two-stage long-pulsed Nd:YAG 1064-nm laser treatment exhibited an encouraging efficacy and safety modality in patients with onychomycosis.
The datasets generated and analyzed during this study are available from the corresponding author upon reasonable request.
There are no financial or other conflicts of interest.