This post contains images and figures drawn from research papers investigating the efficacy of red light phototherapy in the treatment of acne vulgaris. In this section, we focus only on red light alone (not in combination with blue light or PDT). The images shown here were generated from therapies that used LED or standard light sources (not lasers or IPL).
Red Light Phototherapy Alone is Only Mildly Helpful in Treating Acne
A study that compared red light phototherapy lone versus red light photodynamic therapy (PDT) found that red light alone produced a mild improvement. The researchers observed a decrease in inflammation, but not in P. acnes bacteria or sebum levels. This indicates that red light may be helpful by decreasing inflammation, but does not address some of the more fundamental causes of acne.
The Use of LED-Based Red Light Photherapy in Skin Repair and Rejuventaion
While red and blue light are often used together in the treatment of acne vulgaris, red light alone is usually reserved for photorejuvenation treatments. Several research studies indicate that red light from 600-900 nm stimulates the growth of new tissue in the skin and the production of collagen. Additionally, red light appears to assist in the resolution of inflammation, redness and other types of uneven skin tone. Scientists have some ideas about how red light might effect these changes in skin tissue, but the exact mechanism (or mechanisms) are not well understood. Nonetheless, the results speak for themselves in this increasingly popular, mild and non-invasive treatment.
Red Light Phototherapy for the Treatment of Erythema (Permament Redness of the Skin)
Erythema is a common type of skin discoloration that can occur during or after acne outbreaks. It is generally caused by damaged or dilated capillaries near the skin surface. Red light phototherapy likely improves the condition be stimulating the repair of the damaged tissue. Other popular treatments for erythema include the use of lasers to ablate (destroy) the offending capillaries. Those techniques often use a laser that targets the hemoglobin in the blood of the capillaries, like Pulsed Dye Lasers (PDL).
Fine lines and other Skin Irregularities
Red light phototherapy is an increasingly popular method of photo-rejuvenation for people looking to improve the tone, elasticity and general appearance of their skin. While red light phototherapy does not generally produce the dramatic improvements seen in more invasive techniques, like laser resurfacing, it does have a positive track record, is non-invasive and is relatively inexpensive. Additionally, systems can be purchased for at-home use, which can yield big savings over time. Because red light stimulates growth of skin tissue and the production of collagen, it can be used to improve minor wrinkles, acne scars and the general appearance of the skin.
The effect of red light on collagen production
Red light induces the production and remodeling of collagen and elastin fibers. Collagen and elastin are protein based fibers that are produced by cells in the dermis, like fibroblasts. These fibers form an interconnected matrix that provides structural support and elasticity to the skin. A healthy matrix is one where the fibers form a three dimensional, interconnected structure that is capable of stretching and compressing in all directions. As the skin is damaged or ages, the density and organization of collagen and elastin in the skin tends to deteriorate. Scar tissue is formed primarily of collagen, but unlike a healthy collagen matrix, scar tissue is densely packed and poorly structured, resulting in deficient elasticity, functionality and poor appearance. Increasing the production of healthy collagen and elastin in the skin is one of the primary goals in skin rejuvenation procedures.
References and Sources.
A prospective, randomized, placebo-controlled, double-blinded,and split-face clinical study on LED phototherapy for skinrejuvenation: Clinical, profilometric, histologic, ultra-structural, and biochemical evaluations and comparison of three different treatment settings.
Lee, et al. 2007. For article abstract, click here.
Single Low-dose Red Light is as Efficacious as Methylaminolevulinate–Photodynamic Therapy for Treatment of Acne: Clinical Assessment and Fluorescence Monitoring.
Hörfelt, et al. 2009. For article abstract, click here.
Clinical Trial of a Novel Non-Thermal LED Array for Reversal of Photoaging: Clinical, Histologic,and Surface Profilometric Results.
Weiss, et al. 2005. For article abstract, click here.
Effect of NASA Light-Emitting Diode Irradiation on Wound Healing.
Whelan, et al. 2001. For article abstract, click here.