Antimicrobial effects of blue light therapy against cutibacterium acnes: optimal dosing and impact of serial treatments.
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Acne vulgaris is a major health and social concern for many adolescents and adults. The goal of this study was to further assess the efficacy and safety of a United States Food and Drug Administration cleared light-emitting diode (LED) therapy (Omnilux Clear, GlobalMed Technologies) for treating adolescents and adults with mild-to-moderate facial acne. The device is a wearable facial mask designed for home use that simultaneously emits light in red (633 nm) and blue (415 nm) wavelengths. The study enrolled male (n=15) and female (n=15) patients aged 14 to 45 years old. Patients were required to have an Investigators Global Assessment (IGA) score of 2 (mild) or 3 (moderate). Patients applied the treatment at home 4 times weekly, never more than once daily, and allowed 24 hours between treatments. The primary efficacy endpoints were the change from baseline in inflammatory and noninflammatory lesion counts, and the proportion of patients achieving a ≥1-grade reduction in IGA scores from baseline. Other assessments included quality of life and tolerability questionnaires. After 7 weeks, there were significant reductions in inflammatory and noninflammatory lesion counts (for each, p<0.0001) and most patients (86%) achieved ≥1-grade reduction in IGA scores, meeting study success criteria. The few reported adverse events were mild and transient. The primary limitation of this study was the open-label study design. These results provide strong support for this wearable LED device for the safe and effective home treatment of adolescents and adults with mild-to-moderate acne. Blue light therapy (BLT) is a Food and Drug Administration cleared modality used in dermatology as an effective treatment of acne. The primary purpose of this study is to determine if there are dose-dependent antimicrobial effects of BLT against Cutibacterium acnes (C. acnes). A known strain of C. acnes was grown on chocolate agar in a controlled laboratory environment under anaerobic conditions for 1 week. After 1 week, 2-3 colonies of C. acnes were isolated and transferred to broth medium to incubate for 2 or 7 days. Broth vials (treatment arm) then underwent 1 of 6 different blue light dosing treatment regimens and a duplicate broth vial served as a control left open to the same environment. The BLT regimens were a single treatment of 25 J/cm2, 50 J/cm2, 75 J/cm2, 100 J/cm2, 2 serial treatments of 50 J/cm2 separated by 24 hours, or 2 serial treatments of 75 J/cm2 separated by 24 hours. The Omnilux Blue device (415 nm wavelength) was used for all BLT treatments and delivered, on average, 1.68 ± 0.004 J/min. Following treatment, the control and treatment broth samples were plated on chocolate agar and allowed to grow for 7 days. After 7 days, plates were counted and colony forming units (CFUs) were calculated. Six trials were completed for each BLT dosing regimen based on an a priori power analysis of 6 individual 2-sided t-tests. Comparisons in the primary outcome were made via mixed-effects analysis of variance with replicate as a random effect. All BLT treatment regimens resulted in significantly fewer CFUs than their aggregate control plate CFUs (P < .05 for all). Furthermore, in 2-way comparison of CFUs between BLT treatment groups, a single treatment of 75 J/cm2 did lead to significantly less growth than 25 J/cm2 (P = .017) and 50 J/cm2 (P = .017). There were no improved antimicrobial effects with serial treatments when comparing 2 doses of 50 J/cm2 with a single dose of 100J/cm2, nor were 2 doses of 75 J/cm2 more efficacious than 100 J/cm2. Using the Omnilux Blue device, it took 44.8 minutes to deliver a 75 J/cm2 dose. BLT is an effective antimicrobial agent against this single virulent strain of C. acnes. Treatment dosing of 75 J/cm2 was identified to be the most effective dose per unit time. Serial treatments did not lead to superior antimicrobial effects over a single, high-dose treatment. Within the field of dermatology, advances in the use of light emitting diodes (LEDs) have led to their clinical application for a variety of medical and cosmetic uses. Of note, one phototherapy device has demonstrated beneficial effects over a range of clinical applications (Omnilux™; GlobalMed Technologies, Glen Ellen, California). The study included a literature review of published studies. Using LEDs with frequencies of 415nm (blue), 633nm (red), and 830nm (infrared), this device has demonstrated significant results for the treatment of medical conditions, including mild-to-moderate acne vulgaris, wound healing, psoriasis, squamous cell carcinoma in situ (Bowen's disease), basal cell carcinoma, actinic keratosis, and cosmetic applications. Although photodynamic therapy with the photosensitizer 5-aminolevulinic acid might cause stinging and burning, phototherapy is free of adverse events. We determined that phototherapy using LEDs is beneficial for a range of medical and aesthetic conditions encountered in the dermatology practice. This treatment displays an excellent safety profile. The use of visible or near-infrared spectral light alone for the purpose of skin rejuvenation has been previously reported in the literature. These devices use large arrays of diodes to deliver light to the skin. In this study, a novel method of light-emitting diode (LED) photo rejuvenation incorporating a combination of these wavelengths delivered from a small handheld unit is proposed. Twenty-two subjects with facial rhytides received eight light therapy treatments over a course of 4 weeks, using the Omnilux handheld LED system. Assessment of global skin grading was evaluated at weeks 6, 9, and 12 by a dermatologist. Additional outcome measures included assessments of clinical photography and patient satisfaction scores. Seventy-four percent of the subjects reported a visible improvement in fine lines and wrinkles at 8 weeks posttreatment. Combination red and near-infrared LED therapy delivered from a small portable handheld unit represents an effective and acceptable method of photo rejuvenation. Further studies to optimize the parameters of treatment are required. Light-emitting diode (LED) therapy is an increasingly popular methodology for the treatment of sun damage. Combination use of light wavelengths reported to stimulate collagen synthesis and accelerate fibroblast-myofibroblast transformation may display a composite rejuvenative effect. To clinically assess reduction in sun damage signs following a 5-week course of LED therapy and to assess subject's perception of the treatment. Thirteen subjects with wrinkles or fine lines in the periorbital and nasolabial region and those presenting Glogau scale photodamage grade II-III received nine 20-min duration light treatments using the Omnilux LED system. The treatments combined wavelengths of 633 and 830 nm at fluences of 126 and 66 J/cm(2), respectively. Sun-damage reduction was assessed at 6, 9, and 12 weeks by clinical photography and patient satisfaction scores. The majority of subjects displayed "moderate" (50%) or "slight" (25%) response to treatment at investigator assessment. Treatment of the periorbital region was reported more effective than the nasolabial region. At 12-week follow-up, 91% of subjects reported improved skin tone, and 82% reported enhanced smoothness of skin in the treatment area. Good response to LED therapy has been shown in this modest sample. Larger trials are needed to assess optimum frequency of light treatments and overall treatment time. The use of visible or near infrared spectral light alone for the purpose of skin rejuvenation has been previously reported. A method of light emitting diode (LED) photo rejuvenation incorporating a combination of these wavelengths and thus compounding their distinct stimulation of cellular components is proposed.Objective. To assess the efficacy and local tolerability of combination light therapy in photo rejuve