October 26, 2021: Do lasers work on nail fungus? An in depth review.

Do lasers ‘cure’ fungal nails?

Lasers have been a part of podiatry practice for a number of years.

Papers discussing the potential use of lasers in clinical practice started to appear in the 80s, focusing on the high powered carbon dioxide (CO2) systems available at that time.

Evaluation was around nail bed removal, treatment of onchomycosis (nail fungus) once the nail had been removed, and nail fenestration (making a hole or ‘window’ in the nail) to facilitate more effective treatment by topical applications such as curanail.

However the small number of machines in use remained in the hands of specialists, and mainly in the United States. As the years passed, new systems were introduced with varying levels of success but the main prohibition to their use in clinical practice was their cost.

In 2009, for the first time a surgical laser system advertised in the UK Podiatry magazine Podiatry Now was claimed by one user to be ‘possibly the most radical development in the treatment of onychomycosis our profession has ever seen’.

Concerns were raised at the time as these were unproven claims for expensive equipment and in the years since little evidence has been put forward demonstrating their effectiveness despite their increasingly wider use.

Lasers are attractive for the public and practitioner alike for a number of reasons.

Although oral medications have shown effectiveness and remain the most studied treatment for onychomycosis(fungal nail), concern is always expressed about their safety. Antifungal drugs are contra-indicated in patients with active or chronic liver disease and are often declined by patients wishing to avoid potential side-effects.

Topical applications also have drawbacks with long term application, questionable efficacy, and issues with patient compliance.

Lasers, however, capture the imagination as a safe, effective quick fix for a number of conditions. However, how they work remains unclear.

Laser systems in near infra-red spectrum (780 nm – 3000 nm wavelength), which are commonly used in onychomycosis, directly heat target tissues and by using a pulsed beam instead of continuous one, they can deliver a “selective photothermolysis”

Appropriate intervals between pulses allows for tissue relaxation and cooling causing little collateral damage to surrounding structures. Lasers for nail disease have been approved by the Food and Drug Administration (FDA)in America but only for their ability to temporarily clear nail growth in mycotic nails.

An immediate problem with the studies was the variety of study procedures which made comparison difficult.

12 papers published between 2010 -2014 reflected the novelty of the technology with four studies stated they were “preliminary” or pilot studies.

10 papers investigated the 1064 nm neodymium: yittrium-aluminum-garnet laser system (Nd:YAG) (long and short pulse types). 1 paper used an 870/930 nm dual band system and another investigated the use of an ablative carbon dioxide laser as a means to fractionate nails to improve the penetration of topical anti-fungal agents.

In one randomized controlled trial, 36 patients with proven onychomycosis (nail fungus) were randomly allocated to either a laser treatment or control sham device.

All patients were treated at day 1, 14, 42 and day 60. Independent assessors reviewed photographic evidence at various stages to judge and record any changes at 6 months, when 34 patients (37 toes: 26 treated and 11 controls) were valid for analysis.

Visually, only 2 treated nails had completely or markedly improved and slight to moderate improvement was seen in 18 treated nails versus 3 control nails with 6 treated nails unchanged along with 6 control nails.

The study was funded exclusively by a laser manufacturer and employees of the company were shown as co-authors of the paper.

In another randomized controlled trial 27 patients with onychomycosis received either 2 laser treatments two weeks apart or no treatment. After 3 and 12 months all patients were re-assessed by culture and measured nail clearance.

At 3 months, 33% of the laser treated group had a negative culture versus 20% in the control group and had more proximal (new uninfected growth emerging from the bed) nail clearance at this time, although there was no statistically significant difference between the two groups.

At 12 months, there was no difference in measured nail clearance between the treated and control group.

One conclusion was that laser may only have a temporary effect in onychomycosis.

Another study of 8 patients suggested 7 showed distinct improvement 4 months after 2–3 laser treatment 3 weeks apart. However, it was a small group, pre and post assessment was vague and patients were encouraged to use daily anti-fungal agents applied to the nail during treatment.

Another study in 2012 study looked at 13 subjects (37 toe nails). Nails were treated two or three times 4–8 weeks apart. At the end of the study (week 16) 19 nails (51%) showed complete clearance (clear nail and negative microscopy) with 30 nails (81%) showing from moderate to complete improvement.

Equipment for the study had been loaned from the manufacturers but it is not known if the results were independent of the company.

A more recent study looked at 43 toenails and 12 finger nails that underwent laser 5 treatments at four week intervals. At 24 weeks nails were assessed for surface clearance and negative cultures. 1 month after the final treatment 30 of the 43 nails were clear of fungus. 4 nails achieved a complete cure. 8 patients were reported to have achieved better than 80% clearance and 31 nails showing a substantial improvement.

The Pinpointe™ Laser was used on two randomly assigned treatment groups comprising 33 patients with 154 fungal nails given 8 treatments at 1 week intervals (group 1) or 4 treatments at 1 week intervals (group 2).

At 24 weeks there was no significant difference in the cure rates between the groups. What was interesting was the reported re-occurrence of fungus reported on 10 nails (5 patients) within a 2–4 months, suggesting that laser may only inhibit growth rather stopping it altogether.

A more involved study used three types of laser light on 21 patients. Each nail was treated with 10 minutes of laser light and received 4, weekly treatments and were assessed at 1, 3 and 6 months. Tissue temperature was recorded to suggest what effect the laser was having on the treated area and although the results appeared good, it was a small sample. However, it is possible 46 degrees Centigrade is a lethal temperature for nail fungus

A larger study of 131 patients underwent 2 treatments, 30 days apart with a review at two months. The review at 2 months suggested a good initial success rate but there was no long-term follow-up to determine re-growth rates.

Another study of 12 nails treated by laser concluded that it was no better than topical nail lacquer therapy based on the cure rates achieved. Again, a study of 10 patients (18 nails) with onychomycosis could not show significant improvements in mycological or clinical cure rates after a 24 week program using laser.

In another group of 10 nails, clinically only 4 cases had shown visible improvement. This last study unsurprisingly concluded that mild superficial fungal nail infections are more likely to respond than well established infections that have penetrated under the nail.

This review highlights a number of issues.

  • From early results it is clear that there is no agreement on the effectiveness of laser with conflicting results. This, in part, is due to the differences in study design.
  • Although all papers reviewed fungal nails in adults, selection criteria varied.
  • Most focused on older adults reflecting the fact that onychomycosis (fungal nail) is a disease are more prevalent in this age group.
  • There was no standard test to confirm onychomycosis with a large number of tests used of varying reliability.
  • How a ‘cure’ is measured or defined with no agreed standard.
  • Visual appearance in some studies was based on patient satisfaction, whilst others measured clear nail emergence or simply measured the changes in the amount of nail plate surface affected and its associated changes.
  • Variation in length of study from 12 weeks to 1 year.
  • No account is taken of differences in nail growth rate with age, or that fungal nails grow more slowly in the first place. In adults, toenails grow approximately 1.0 mm/month however in the elderly, the rate of nail growth decreases by approximately 0.5% per year between 25 to 100 years of age.
  • A greater study period is required as the longer studies hint at re-occurrence being an issue, although this could be due to outside factors such as contaminated footwear. This suggests topicals such as Curanail/Loceryl being a useful addition to a successful treatment regime.
  • There were variations in nail thickness and some used a nail drill to reduce the presence of diseased nail prior to treatment.
  • With four main types of onychomycosis, what was being treated also varied.
  • The cost a long term study is expensive and sponsorship can effect outcomes or interpretation of findings, only one paper disclosed what could be a conflict of interest
  • There is no actual single protocol for laser toenail fungus treatments.
  • there have been no solid studies to prove that the laser can cure toenail fungus.

In later studies by Jager, Oesterhelt, Et Al, they found that no patient had a fungal cure in 12 months of treatment and follow-up.

In 2016, in Podiatry Today, Tracey Vlahovic, DPM, a leader in Podiatric Dermatology noted that laser is not a reliable monotherapy for toenail fungus.

In 2019, Harvard University noted that “there is still little information about its long-term safety and effectiveness”. In the Journal of Fungi, Liddell and Rosen concluded that with laser therapy for toenail fungus, “The evidence to date has not indicated superior outcomes in long-term endpoints to standard of care systemic therapy and postulated anti-fungal mechanisms remain unverified’.

There is a scarcity of peer-reviewed literature investigating this topic and with so many types of lasers and so many different treatment protocols, there truly is no way of knowing which types of lasers have better results and which protocols are best.

Further, there are no true studies to confirm the laser treatment effectiveness, although there is much marketing material making the claim. When you combine all of that with the cost, it is difficult to recommend laser for toenail fungus at this time.  As noted in the studies above, traditional treatments were often as good or better than laser therapy alone, and there are many other treatments available to help with this condition.

At Maidenhead Podiatry, we will wait to see if new evidence supports the use of laser. At this time, we have found that it may not in your best interest to seek laser treatment and we will continue to offer traditional treatments for toenail fungus.

The review itself cannot have been exhaustive, may not have included all relevant papers and only looked at studies in English.