๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
LASERS AND LIGHT-BASED THERAPY
LASERS AND LIGHT-BASED THERAPY
Increased antibiotic resistance to P. acnes and adverse effects of retinoids and antibiotics have led to the growing demand for light-based therapy. P. acnes contain endogenous porphyrins which can be targeted through visible light (with an absorption peak of 415 nm), resulting in destruction of the bacteria.24
Light emitting diodes (LEDs) are a popular phototherapeutic modality, and 670-nm LED therapy has been described for the induction of rapid wound closure and tissue regeneration, while downregulating cytokine-encoding genes. Several other studies have attributed various success rates to phototherapy using blue light. For example, Morton et al. reported the efficacy of a blue light source on inflammatory acne lesions. The results showed a mean 34% improvement in noninflammatory lesions and a 78% improvement in inflammatory lesions.25
Lee et al. conducted a study to evaluate the success rate of phototherapy using blue and red light sources (which peak at 415 and 633 nm, respectively) on mild to moderately severe facial acne. They reported that after the therapy, moisture and sebum levels decreased only slightly while the melanin level showed a significant decrease. Although not offering significant clinical improvement, this treatment may have a brightening effect on skin tone.26
In another study by Papageorgiou et al., a combination of blue and red light from fluorescent lamps resulted in a mean improvement of 58% in comedones and a 76% improvement in inflammatory lesions,27 highlighting the possible advantage of a mixed light approach as opposed to blue light alone. This may be due to the combination of antibacterial and anti-inflammatory properties of blue and red light, respectively.26
Studies have also addressed the positive effects of red light therapy, with one in vitro study demonstrating that red light affects cytokine release from macrophages, stimulating fibroblast proliferation.28 According to another study by Karu, red light absorption can alter the redox status of the respiratory chain components and consequently stimulate
cellular proliferation.29
Overall, light-based acne therapy is currently growing in popularity, and its effects can be divided into three groups: photochemical, photothermal, and a combination of both. Alternatively, light-based therapy can be categorized according to its target, such as P. acnes, the follicular infundibulum, and the sebaceous glands.30