Acne vulgaris is a skin disorder that occurs when hair follicles become obstructed with oil and dead skin cells causing inflammation of the follicle and their accompanying sebaceous gland. Acne develops on the face and upper trunk. It affects people of all ages, but most common among adolescents. Acne is one of the most common diseases worldwide and affects ∼50 million individuals in the United States.
Acne can be classified as
- Noninflammatory: Characterized by comedones. Open comedones are blackheads - black because of surface pigment (melanin), rather than dirt. Closed comedones are whiteheads - the follicle is completely blocked.
- Inflammatory: Characterized by papules, pustules, nodules, and cysts
As active breakouts were not frustrating enough, both types leave behind scars and hyperpigmentation.
Therapeutic options in acne, typically include topical and oral antibiotics, retinoids, and hormone modulating therapies (in female patients). Oral antibiotics are the most common systemic agent prescribed for the treatment of acne. However, their use might be associated with a variety of adverse outcomes including bacterial resistance and disruption of the microbiome.
Lasers provide one of the most promising alternatives to topical and systemic drugs acne treatments. Traditionally, light therapy has been reserved for the treatment of acne scarring, but its utility is increasingly being recognized in active acne management. The future looks bright for treating acne with lasers. These treatments show great promise in treating acne. Some patients with severe acne cysts have seen clearing for years when laser therapy was added to their treatment plan.
In theory, it’s easy - just beam a light onto skin to make the acne disappear. However, using lasers for acne treatment is not quite straightforward, and the results less predictable, even in the skilled hands of a dermatologist. A lot depends on the right choice of laser for a particular patient.
No one laser can treat pimples, blackheads, whiteheads, acne cysts, and acne nodules. That’s why different types of lasers and light therapies are used to treat acne. The following explains what the different types of lasers can — and cannot — treat.
1550 nm erbium glass laser
While frequently used to treat acne scarring, the 1550 nm fractional erbium glass laser has also more recently been studied and used in the treatment of active acne, particularly inflammatory acne. Limited uncontrolled studies have demonstrated improvement in acne with the use of the 1550 nm erbium laser. Notably, these responses also appear to be long-lasting. These durable responses after 1550 nm erbium glass laser treatment are attributed to a reduction in sebaceous gland size observed on histological exam of treated skin. The 1550 nm erbium laser appears to be well tolerated for acne treatment. It is worth noting that no chromophores in human skin has specific absorption band at 1550nm, and the absorption spectrum is dominated by water. Therefore, most likely the positive outcome of the treatment is the result of local heating.
The power density in the range of 15 –30 mJ/cm2 was used in these studies. This level of power density can be easily achieved with AKELA’s high-power laser diode modules at a fraction of the cost of Solid Sate Er-glass Laser
1540 nm erbium glass laser
Several uncontrolled studies have evaluated the efficacy of the 1540 nm erbium glass laser for the treatment of acne. These studies rated improvement as significant in all patients. Additionally, patients all reported being satisfied or very satisfied with the treatment and had only mild temporary side effects including slight erythema and edema. Similarly, another study also found high patient satisfaction with the 1540 erbium glass laser for active acne. 85% patients felt that active acne had improved and 45% classified their acne as much improved. Given very small difference in the wavelength between 1550nm and 1540nm, and broad absorption bands of every chromophore in human body, one should assume that there should be very little if any difference in efficacy of treatment with these two wavelengths. However, the reported power density for the 1540nm was lower (5 –10 mJ/cm2). It could be just a consequence of being closer to the water absorption peak at 1470nm.
AKELA Laser offers several high-power laser modules operating at 1540nm as well as at 1470nm. These modules provide economical alternative to bulky and expensive Er-glass lasers.
1064 nm Nd:YAG laser
Because it targets the dermis, the 1064 nm Nd:YAG laser has been studied most extensively in the treatment of acne scarring. However, several studies have documented successful treatment of active acne with this laser. The reduction of both inflammatory and noninflammatory acne lesion counts was reported While the mechanism remains to be elucidated, similar to the 1550 nm erbium glass laser, the 1064 nm Nd:YAG likely treats acne through a reduction in sebum production and inflammation. It was also reported the cytokine reductions, which suggest that, in addition to destroying the sebaceous gland, the laser decreases inflammation at the level of gene expression.
While preliminary studies and case reports suggest that the 1064 nm Nd:YAG can successfully be utilized for the treatment of active acne, there are no controlled studies examining this modality. Treatments with the 1064 nm Nd:YAG laser are relatively safe with the most common side effects including redness, dryness, and tenderness. Additionally, treatments are not associated with appreciable downtime.
Relatively short pulses 300 μs and fluence of 1.8 to 2.0 J/cm2 were utilized in these studies. AKELA Laser offers many high-power laser diode modules operating at 1064nm that can be used in medical devices instead of more expensive Nd:YAG lasers
1320 nm Nd:YAG laser
This laser has only been studied to a limited extent in the treatment of acne. Statistically significant reductions in inflammatory and noninflammatory lesions, as well as decreased sebum levels were reported, leading the authors to postulate that the laser treats acne through a reduction in sebum production. The 3 days of erythema without pigmentary complications were reported as the only side effects.
A fractional 1320 nm Nd:YAG laser (10–15 J/cm2), can be easily replaced by a 1320nm high-power laser diode modules that AKELA Laser manufactures.
1450 nm diode laser
The limited uncontrolled studies evaluating the efficacy for the 1450 nm diode laser for the treatment of active acne have shown long-term benefit and safety for acne even in patients with darker skin types. However, it was discovered that treatments with the 1450 nm diode laser were not associated with marked changes in sebum excretion compared to controls, thereby questioning the mechanism of action for the 1450 nm diode laser in the treatment of acne. Further studies need to clarify the efficacy of the 1450 nm diode laser for acne and its mechanism of action.
AKELA Laser Corp. manufactures the highest power 1450nm laser diodes suitable for applications in medical devices for acne treatment.
1720 nm diode laser
Preliminary studies evaluating the efficacy of 1720nm laser diode showed a lot of promise in using this wavelength for treating acne. 1720nm corresponds to the absorption peak of fat and protein in the skin, therefore specifically targeting the sebaceous gland. The use of 1720nm offers the unique opportunity to treat any skin type, as there is no absorption by melanin at this wavelength.
AKELA Laser Corp. has developed high power 1720nm laser diode modules for this application.
Pulse dye laser
Both 585nm and 595 nm pulse-dye lasers (PDL) laser (both 585 and 595 nm) are popular instruments to target vascular lesions and can treat atrophic acne scarring. Recently they been studied in the treatment of active acne with mixed results. Its mechanism of action for the treatment of acne is not well understood. While many of the other lasers used to treat active acne have been shown to impact sebum production, PDL has not. Studies examining the use of PDL for the treatment of acne are limited in number and sample size. Moreover, most of the studies involve the 585 nm laser which is used less frequently now. Also, based on the available data, the PDL laser seems to be less efficacious than some of the other laser modalities for the treatment of active acne.
532nm Green laser. This wavelength is obtained by doubling the frequency of Nd:YAG laser in KTP crystal. This is why in medical community it is often referred as KTP laser. It targets chromophores of oxyhemoglobin and melanin. As a result, KTP lasers are traditionally used for the treatment of telangiectasias and other vascular indications such as rosacea. KTP’s proposed mechanism of action in acne treatment is through photoactivation of porphyrins and resultant destruction of P. acnes. Only a few studies have investigated the use of KTP for acne, with inconsistent results. Split-face studies have shown mild improvement that appears to be transient and not dose dependent. Further studies are needed to elucidate the utility of KTP in the treatment of active acne.
AKELA Laser Corp. offers high-power green laser diode module, that can replace expensive KTP in most applications.
Photodynamic therapy (PDT)
PDT uses light in combination with a photosensitizer, typically applied topically, for treatment. Three topical agents can be used as the photosensitizers in PDT of acne: aminolevulinic acid(ALA), methyl aminolevulinate, and indocyanine green, with ALA being the most commonly utilized. While PDT with blue and red light has been documented to be an effective acne treatment, the results with PDT used with the PDL and KTP lasers have been mixed. When ALA is applied to the skin, it is preferentially taken up by the pilosebaceous unit and is then converted to protoporphyrin IX through the heme synthesis pathway. When protoporphyrin IX is photoactivated by the light source, singlet oxygen species are created, and free radicals cause the destruction of P. acnes and the pilosebaceous unit. As a result, repeated ALA-PDT treatments cause destruction and marked atrophy of sebaceous glands. The evidence for PDT with lasers for acne is positive but limited, with several studies reporting complete clearance. While other treatments discussed have limited downtime and mild side effect profiles, the addition of a photosensitizer can be associated with pain, continued photosensitivity requiring light avoidance, and more exuberant inflammatory reactions after treatment.
AKELA Laser Corp. has developed a turn-key system for PDT, which uses laser diodes emitting light at several wavelengths suitable for excitation of photosensitizers.