Lasers in the therapy of various nail conditions

The main indications for laser treatments of the nail are ingrown nails, onychomycosis, psoriasis, and a range of tumours and pseudotumours.

Ingrown nails

Ingrown nails are a common ailment significantly interfering with daily work, sports activities, and lowering overall quality of life. The number of different treatment recommendations is immense 15. The choice of technique depends on the type of ingrown nail, the most common form being distal lateral ingrowing. Matrix destruction achieves better results than matrix preservation. Carbon dioxide (CO2 ) lasers have been used since the 1980s, especially for matrix horn ablation 16,17 . A number of treatment techniques have been reported:

  • Vapourisation of the nail matrix with or without section at the angle of the proximal and lateral nail folds18
  • Matricectomy with CO2 laser after nail matrix staining19
  • Matricectomy associated with vapourisation of the lateral fold, lateral groove, and granulation tissue20.

The advantage of the CO2 laser is that it allows the skin to be cut with the focused superpulse mode beam, and to vapourise the tissue with the continuous mode. Parameters used are variable depending on the device. The CO2 laser only causes moderate bleeding because the laser cauterises small blood vessels. Postoperative pain is moderate, infection is rare. It is a time-saving technique that allows precise and selective matrix horn destruction, and healing is fast (Figure 1). Recurrence rates are variable in the authors’ experience. The CO2 laser may also be used to reduce a hypertrophic lateral nail fold or to perform Dubois’s plasty with less bleeding and less postoperative pain compared with traditional surgery. It has also been used with success to treat pincer nail deformity 21.

Figure 1 Procedure for laser beam vaporisation. (A) The nail fold is incised at both sides to allow it to be reflected (B) Space over the lateral matrix horn opened to allow access of laser beam (C) Vapourisation of the matrix horn is complete (D) The incisions of the proximal nail fold are sutured

Figure 1 Procedure for laser beam vaporisation. (A) The nail fold is incised at both sides to allow it to be reflected (B) Space over the lateral matrix horn opened to allow access of laser beam (C) Vapourisation of the matrix horn is complete (D) The incisions of the proximal nail fold are sutured

Onychomycosis

Onychomycoses are a group of fungal nail infections that, despite all progress in drug therapy, are still often refractory to medical treatment. New effective topical treatments are needed and laser therapy would be an alternative to the existing treatments. Originally, laser treatment applications were used to create holes in the nails, providing a pathway for the topical treatments to enter the nail 22. Laser therapy involves direct application of laser energy to the treatment site. A study demonstrated the effect of a 1064 nm QS Nd: YAG laser on growth inhibition of Trichophyton rubrum in vitro 23, but another recent study did not find any inhibitory effect with various laser fluences 24.  Nevertheless, some studies demonstrated an effectiveness of lasers in vivo 25,26.

Two studies with a long pulse Nd: YAG laser have been reported. In the first, 194 nails with onychomycosis confirmed by direct and culture examination were treated 27  and 413 nails in the second 28. Parameters used were fluence of 35–40 J/cm2, spot size 4 mm, pulse duration 35 ms, pulse rate 1 Hz, three passes, four sessions with an interval of 1 week; cold air-cooling was necessary during the treatment. At 6 months, 98.8% of patients had mycological clearance. No side-effects or complications were reported.

Another study proposed the use of a Nd: YAG laser (1064 nm) with a short pulse duration at 0.65 ms that allows damage to underlying tissue to be reduced 29. Parameters used were spot size of 2 mm and a fluence of 223 J/cm2; the mean time of treatment for each affected nail was 45 seconds; only eight patients were treated with 2–3 sessions with intervals of 3 weeks. Mycological cure was obtained in half of the patients after two sessions, and seven out of the eight patients showed mycological cure after the last session.

A recent study used a combined approach with atraumatic avulsion of infected nail material, 2–4 passes of Nd: YAG treatment at 200 mJ/cm2, and antimycotic cream 30.

The few studies available are not controlled studies and longer follow-ups are needed to say whether the results are a temporary inhibition of fungal growth or a destruction of fungus. The best device is still to be determined with regard to the number of treatments and the intervals between them. A recent survey not only lists the pertinent publications, but also many studies currently being conducted31,32.

Disruption of the nail plate surface with lasers as well as burning holes may enhance the permeability of the nail for drug penetration into and through the nail 33.  This technique has also been used to improve topical onychomycosis therapy 34.