Innovations in noninvasive procedures keep dermatology on cutting edge

Those who received thermal photorejuvenation laser treatment reported a reduction in posttreatment erythema and an overall impression of increased efficacy with the additional LED treatment – an effect that could be attributed to anti-inflammatory effects of LLLT, they noted.

In another study, more than 90% of 90 patients receiving eight LED treatments over 4 weeks experienced favorable results, improving by at least one Fitzpatrick photoaging category. In addition, 65% of patients experienced global improvement in facial texture, fine lines, background erythema, and pigmentation, with results peaking 4-6 months after completion.

Acne treatment

LLLT in the red to near-infrared (NIR) spectral range (630-1000 nm) and with nonthermal power (less than 200 mW) has been shown in several studies to improve acne vulgaris. In one study, a significant reduction in active acne lesions occurred after 12 twice-weekly sessions using 630 nm red-spectrum LLLT with a fluence of 12 J/cm² in conjunction with 2% topical clindamycin. No significant effects were seen using an 890-nm laser. Other studies have demonstrated that the combination of blue and red light is synergistic for treating acne.

Photoprotection

Recent suggestions that infrared exposure might have protective effects against ultraviolet light–induced skin damage are based on the theory that the exposure might trigger protective or repair responses to UV irradiation. While controversial, this view is supported by data suggesting potential mechanisms of action. For example, some data suggest a role of p53, a sensor of gene integrity involved in cell apoptosis and repair mechanisms. In one study, the response to infrared (IR) irradiation was shown to be p53 dependent, suggesting the IR irradiation prepares cells to resist and/or repair further UV-induced DNA damage. Data from another study showed that IR irradiation induced the protective protein ferritin, which is involved in skin repair.

Data from yet another study suggested that nerve growth factor (NGF) production induced by LLLT using the helium neon semiconductor laser diode (HeNe, 633 nm) might explain the photoprotective effects of LLLT. In that study, NGF – a major paracrine maintenance factor for melanocyte survival in skin, was shown to protect melanocytes from UV-induced apoptosis by upregulating the level of Bcl-2 (an antiapoptotic protein) in the cells.

Herpesvirus lesion treatment

New therapies are needed to shorten recurrent herpesvirus episodes and reduce related pain and inflammation. LLLT has been suggested as an alternative to current medications. In one study of 50 patients with recurrent perioral HSV infection, LLLT at 690 nm, 80 mW/cm², 48 J/cm² daily for 2 weeks during recurrence-free periods decreased the frequency of herpes labialis episodes, the authors said.

In another study with similar parameters, patients achieved a significant prolongation of remission intervals from 30 to 73 days.

The mechanism of action remains unclear, but an indirect effect of LLLT on cellular and humoral components of the immune system may be involved in antiviral responses, as opposed to a direct virus-inactivating effect, the researchers noted.

Vitiligo treatment

Modest efficacy seen with the low-energy HeNe laser (632 nm, 25 mW/cm²) for the treatment of 18 vitiligo patients led to speculation that LLLT could serve as an alternative effective treatment for this typically treatment-resistant condition. (Repigmentation was observed in 64%, and some follicular repigmentation was observed in the remaining patients).

In a subsequent study of local administration of the HeNe laser light at 3 J/cm², 1.0 mW, 632.8 nm in patients with segmental type vitiligo, marked perilesional and perifollicular repigmentation of more than 50% was observed in 60% of patients.

"Both NGF and (basic fibroblast growth factor) stimulate melanocyte migration, and deficiencies of these mediators may participate in the development of vitiligo," the researchers wrote.

Depigmentation

During tests of red and blue light for acne, researchers unexpectedly found that patients treated with both red and blue light experienced an overall decrease in melanin.

Based on instrumental measurement results, blue light exposure (415 nm, 40 mW/cm², 48 J/cm²), increased the melanin level by 6.7, whereas red light exposure (633 nm, 80 mW/cm², 96 J/cm²) decreased the melanin level by 15.5.

"This finding may have some relationship with the laser’s brightening effect of the skin tone, which 14 of 24 patients spontaneously reported after the treatment period. However, as of today, no other studies investigated or reported a similar decrease in melanin levels after red light irradiations," the researchers said.

Hypertrophic scar and keloid eradication

LLLT has shown promise for preventing hypertrophic and keloid scars in patients who undergo scar revision by surgery or CO₂ laser. The use of daily near-infrared LED (NIR-LED) treatment on one of the two bilateral sites safely reduced the risk of scar development in that lesion, compared with the untreated lesion in three patients with bilateral scars. One underwent surgical revision/excision for preauricular linear keloids that developed after a face-lift procedure, one underwent CO₂ resurfacing for hypertrophic acne scars on the chest, and one underwent CO₂ resurfacing after excision of hypertrophic scars on the back. No significant treatment-related adverse effects were reported.