Red Light Therapy Research Articles

Successful treatment of Old World cutaneous leishmaniasis with red or green light photodynamic therapy

Cutaneous leishmaniasis is one of the most common travel dermatoses in Germany, which can be acquired not only in Africa, Asia or the American continent, but also in southern European countries. In addition to the currently available topical and systemic therapy options, there have been increasing reports of successful treatment of cutaneous leishmaniasis with photodynamic therapy (PDT) using numerous therapy regimens and different photosensitizers in recent years. We report on successful photodynamic therapy of Old World cutaneous leishmaniasis with red and green light PDT with 10% 5‑aminolevulinic acid.

688 Use of low-level light therapy in management of central centrifugal cicatricial alopecia

Background: Central Centrifugal Cicatricial Alopecia (CCCA) is a scarring hair loss that predominately affects women of African descent. The etiology is unknown, however is proposed to involve genetic, inflammatory, and environmental factors. Treatment includes anti-inflammatory therapies, such as intralesional steroids, topical steroids, and oral antibiotics. However, effective, safe medical therapy is often a challenge for many patients. Low-level red-light therapy has effectively improved androgenetic hair loss by promoting anti-inflammatory factors, however, its use in CCCA management is not well understood.

Red-light radiation: does it enhance memory by increasing hippocampal LRP-1 and TRPA-1 genes expression?

Purpose Despite the extensive efforts to treat the leading cause of neurodegenerative diseases (ND), a little progress has been reported. Red light might affect ND through many specific mechanisms. The purpose of this investigation is to explore the effect of red light on the expression of low-density lipoprotein receptor-1 (LRP-1) and transient receptor potential ankyrin-1 (TRPA-1) gene in the hippocampus, and the serum melatonin level (SML) of the lipopolysaccharide (LPS)-induced neuro-inflammated rats. Materials and methods Red-light therapy was implemented using a wavelength 630 nm under different light conditions and the passive avoidance (PA) and Y-Maze tests were employed to assess memory performance. To evaluate the LRP-1 and TRPA-1 genes expression, quantitive real-time polymerase chain reaction was performed. To measure the SML, ELISA was performed before and after the red-light radiation. Results LPS caused memory impairment in both behavioral tests. Red-light therapy improved PA memory in all light conditions (p < .001). However, in Y-maze, only the red-light radiation during light and dark cycles, improved memory (p < .01 and p < .001, respectively). In addition, red-light radiation caused significant increase in SML (p < .05). The LRP-1 and TRPA-1 genes expression increased significantly during the dark phase in the red light radiated group compared to non-radiated group (p < .001). Conclusions Taken together, the results suggest that red-light therapy can reduce the complications of memory impairment in rats. This study has found that red-light therapy demonstrates higher effect during the period of dark phase compared to light phase. No doubt, further experimental studies would help us to establish a greater degree of accuracy on this matter.

Early detection and treatment device for diabetic foot neuropathy.

Diabetic foot neuropathy is one of the complications of diabetes that affects around 50% of diabetic people. Because peripheral neuropathy involves nerve loss around the foot areas, patients with diabetic neuropathy frequently lose sensation in their feet while walking or standing. Furthermore, since sensory nerves are damaged, the area that holds the majority of the foot pressure and temperature is at high risk of injury. If not diagnosed and treated properly, it can cause foot injury and eventually lead to edema, gangrene, ulcers, amputation, and even death. There are now several techniques of detecting diabetic neuropathy, but they are limited in their availability, cost-effectiveness, and complexity. The primary goal of this research was to develop devices for early detection and treatment of diabetic foot neuropathy. The proposed device combines a foot pressure monitoring method and a foot temperature measurement method to diagnose diabetic neuropathy early on, with red light therapy added as a treatment method. For 2weeks, the device measures the patient's foot pressure and temperature, and light therapy is provided if a change in pressure or temperature at a specific area is observed. The device prototype was successfully developed, and numerous tests were carried out in accordance with the design specifications. For pressure measurement and temperature measurement, measurement accuracy of 99.05% and 99.30%, respectively, were attained. The early detection and treatment device developed in this study could be used at home by diabetic patients as well as in hospitals to test for and treat diabetic foot neuropathy at an early stage. The device incorporates two different methods of diabetic foot neuropathy detection with high measurement accuracy which makes it suitable for use in resource-limited areas at low cost. The incorporation of red light therapy together with the two methods of diabetic neuropathy detection gives another unique feature for our device.

Low-intensity, long-wavelength red light slows the progression of myopia in children: an Eastern China-based cohort.

To determine the effect of low-intensity, long-wavelength red light therapy (LLRT) on the inhibition of myopia progression in children. A retrospective study was conducted. One hundred and five myopic children (spherical equivalent refractive error [SER] -3.09±1.74 dioptres [D]; mean age, 9.19±2.40years) who underwent LLRT treatment (power 0.4mW, wavelength 635nm) twice per day for 3min each session, with at least a 4-h interval between sessions, and a control group of 56myopic children (SER -3.04±1.66D; mean age, 8.62±2.45years) were evaluated. Both groups wore single-vision distance spectacles. Each child returned for a follow-up examination every 3months after the initial measurements for a total of 9months. At 9months, the mean SER in the LLRT group was -2.87±1.89D, significantly greater than that of the control group (-3.57±1.49D, p<0.001). Axial length (AL) changes were -0.06±0.19mm and 0.26±0.15mm in the LLRT group and control group (p<0.001), respectively. The subfoveal choroidal thickness changed by 45.32±30.88μm for children treated with LLRT at the 9-month examination (p<0.001). Specifically, a substantial hyperopic shift (0.31±0.24D and 0.20±0.14D, respectively, p=0.02) was found in the 8-14year olds compared with 4-7year old children. The decrease in AL in subjects with baseline AL >24mm was -0.08±0.19mm, significantly greater than those with a baseline AL ≤24mm (-0.04±0.18mm, p=0.03). Repetitive exposure to LLRT therapy was associated with slower myopia progression and reduced axial growth after short durations of treatment. These results require further validation in randomised controlled trials.

Antiangiogenic activity of photobiomodulation in experimental model using chorioallantoic embryonic membrane of chicken eggs.

The purpose of this study was to investigate the vascular effects of photobiomodulation using a light-emitting diode on the chorioallantoic embryonic membrane of chicken eggs grouped into different times of exposure and to detect the morphological changes induced by the light on the vascular network architecture using quantitative metrics. We used a phototherapy device with light-emitting diode (670 nm wavelength) as the source of photobiomodulation. We applied the red light at a distance of 2.5 cm to the surface of the chorioallantoic embryonic membrane of chicken eggs in 2, 4, or 8 sessions for 90 s and analyzed the vascular network architecture using AngioTool software (National Cancer Institute, USA). We treated the negative control group with 50 μl phosphate-buffered-saline (pH 7.4) and the positive control group (Beva) with 50 μl bevacizumab solution (Avastin, Produtos Roche Químicos e Farmacêuticos, S.A., Brazil). We found a decrease in total vessel length in the Beva group (24.96% ± 12.85%) and in all the groups that received 670 nm red light therapy (2× group, 34.66% ± 8.66%; 4× group, 42.42% ± 5.26%; 8× group, 38.48% ± 6.96%), compared with the negative control group. The fluence of 5.4 J/cm2 in 4 sessions (4×) showed more regular vessels. The number of junctions in the groups that received a higher incidence of 670 nm red light (4× and 8×) significantly decreased (p<0.0001). Photo-biomodulation helps reduce vascularization in chorioallantoic embryonic membrane of chicken eggs and changes in the network architecture. Our results open the possibility of future clinical studies on using this therapy in patients with retinal diseases with neovascular components, especially age-related macular degeneration.

Abnormalities in Cutaneous Microcirculation in Patients with Alzheimer's Disease, Mild Cognitive Impairment, and Chronic Insomnia Disorder.

Impaired sympathetic response is frequently observed in neurodegenerative diseases, such as Alzheimer’s disease (AD). On the other hand, chronic insomnia disorder (CID) is also often accompanied by activation of sympathetic nerves. Considering that cutaneous microcirculation reflects sympathetic tone, we hypothesized that baseline cutaneous microcirculation in fingers, as detected by laser Doppler flowmetry (LDF), differs among patients with mild cognitive impairment (MCI), AD, and CID. As light therapy is one of the adjunctive treatments for AD and CID, we designed a randomized controlled cross-over trial of light therapy through eyes for 12 weeks with red light as treatment and green light as control limb, and examined if light therapy has an impact on cutaneous microcirculation. Before light therapy, patients with AD had significantly lower baseline cutaneous perfusion than those with CID in left and right first to fourth fingers. After red light therapy, however, cutaneous perfusion of fingers in CID patients significantly decreased (right fingers, before vs. after = 227.25 ± 62.00 vs. 162.00 ± 49.34, p = 0.007; left fingers, before vs. after = 228.99 ± 58.80 vs. 177.41 ± 59.41, p = 0.003) while cutaneous perfusion of fingers in CID patients did not significantly change after green light therapy. Light therapy with red light also significantly increased cutaneous finger perfusion in patients with AD (right fingers, before vs. after = 130.13 ± 49.82 vs. 172.38 ± 38.32, p = 0.043). Our results suggest that cutaneous perfusion is a useful tool to detect sympathetic dysfunction in patients with CID and AD, and that light therapy with red light is a potential therapeutic intervention to reverse impaired sympathetic function in patients with CID and patients with AD.

Effect of Repeated Low-Level Red-Light Therapy for Myopia Control in Children: A Multicenter Randomized Controlled Trial

To assess the efficacy and safety of repeated low-level red-light (RLRL) therapy in myopia control in children. Multicenter, randomized, parallel-group, single-blind clinical trial. Two hundred sixty-four eligible children 8 to 13 years of age with myopia of cycloplegic spherical equivalent refraction (SER) of -1.00 to -5.00 diopters (D), astigmatism of 2.50 D or less, anisometropia of 1.50 D or less, and best-corrected visual acuity (BCVA) of 0.0 logarithm of the minimum angle of resolution or more were enrolled in July and August 2019. Follow-up was completed in September2020. Children were assigned randomly to the intervention group (RLRL treatment plus single-vision spectacle [SVS]) and the control group (SVS). The RLRL treatment was provided by a desktop light therapy device that emits red light of 650-nm wavelength at an illuminance level of approximately 1600 lux and a power of 0.29 mW for a 4-mm pupil (class I classification) and was administered at home under supervision of parents for 3 minutes per session, twice daily with a minimum interval of 4 hours, 5 days per week. The primary outcome and a key secondary outcome were changes in axial length and SER measured at baseline and the 1-, 3-, 6-, and 12-month follow-up visits. Participants who had at least 1 postrandomization follow-up visit were analyzed for treatment efficacy based on a longitudinal mixed model. Among 264 randomized participants, 246 children (93.2%) were included in the analysis (117 in the RLRL group and 129 in the SVS group). Adjusted 12-month axial elongation and SER progression were 0.13 mm (95% confidence interval [CI], 0.09-0.17mm) and -0.20 D (95% CI, -0.29 to -0.11D) for RLRL treatment and 0.38 mm (95% CI, 0.34-0.42 mm) and -0.79 D (95% CI, -0.88 to -0.69 D) for SVS treatment. The differences in axial elongation and SER progression were 0.26 mm (95% CI, 0.20-0.31 mm) and -0.59D (95% CI, -0.72to-0.46 D) between the RLRL and SVS groups. No severe adverse events (sudden vision loss ≥2 lines or scotoma), functional visual loss indicated by BCVA, or structural damage seen on OCT scans were observed. Repeated low-level red-light therapy is a promising alternative treatment for myopia controlinchildren with good user acceptability and no documented functional or structural damage.

Treatment of androgenetic alopecia with 5-aminolevulinic acid photodynamic therapy: A randomized, placebo-controlled, split-scalp study of efficacy and safety

Background and objectivesAndrogenetic alopecia (AGA) is one of the most common hair loss disorders. Treatment options for AGA are limited . New therapies for AGA are clinically needed. 5-aminolevulinic acid photodynamic therapy (ALA-PDT) is widely applied in diseases involving the pilosebaceous unit. However, limited research has explored the efficacy of ALA-PDT in treating alopecia. Some studies reported hair regrowth after PDT in alopecia areata patients, but the efficacy of ALA-PDT on AGA remains unclear. The objective of this study is to evaluate the efficacy and safety of ALA-PDT for the treatment of AGA. MethodsA randomized, placebo-controlled, split-scalp clinical study was conducted. Subjects with AGA received six sessions of 5% ALA-PDT on one half of their scalp and the red-light therapy on the other half. The treatments were applied every two weeks for six sessions on each subject. ResultsThere were 7 subjects enrolled in this study. No significant difference in hair density was observed between the red-light treatment and ALA-PDT treatment. The hair density in the ALA-PDT treated half of the scalp significantly decreased 1 week after the treatment, then it increased, and no statistical difference was found at 12 weeks after the last treatment compared to the baseline. There was no significant improvement in hair growth according to a 7-point scale and the subjects’ self-assessments. The main adverse effects in ALA-PDT treatment were mild edema and tolerable pain, and no adverse effect was observed in red-light treatment. Conclusions6 sessions of 5% ALA-PDT did not increase the hair growth of AGA patients, but slightly suppressed the sebum secretion on the scalp. The adverse effects of ALA-PDT were mild, which indicated safety and tolerability of this treatment.

Application of red light therapy for moderate-to-severe acne vulgaris: A systematic review and meta-analysis.

Photodynamic therapy had made great progress in the treatment of acne vulgaris. However, there is no meta-analysis on the effectiveness and safety of red light therapy for acne vulgaris. To assess the efficiency and safety of red light therapy for acne vulgaris. PubMed, Cochrane Library, EMBASE, and Web of Science were retrieved to identify related studies. The outcomes were expressed as improvement in the average percentages of inflammatory acne lesions (MPRI) and non-inflammatory acne lesions (NMPRI), as well as the improvement of acne lesions respectively after treatment. 13 randomized controlled trials (RCTs) consisting of 422 participants were included. There was no significant difference in the average number of non-inflammatory lesions (weighted mean difference (WMD=-0.527; 95% CI,-3.055~2.001; p=0.683). Moreover, there was no statistically significant difference in the average number of inflammatory lesions (WMD =0.701; 95% CI, -0.809~2.212; p =0.363). In the subgroup analysis of the outcome changes in comedones, pustules, papules, and total lesions, it was found that red light therapy elicited no significant superiority compared with other conventional treatment methods (WMD=-1.125; 95% CI, -3.122~0.873; p=0.270). Adverse events of the red light group were generally mild or even completely non-existent. There was no statistically significant difference between red light therapy and traditional therapies in terms of efficacy. However, due to the heterogeneity of the researches and the lack of large sample size, the result of this study needs to be interpreted with caution.

Experimental Studies and the Search for New Innovative Approaches to Treat Dry Eye Disease

Introduction and purpose. The main manifestation of eyelids, tear ducts, and orbits disorders is a dry eye disease considered as a serious disease that affects the quality of life. Nowadays, one in ten people worldwide faces this disease. Increased workload, development of multimedia technologies, hypodynamia, and environmental degradation are the main modern causes of the disease. Material and methods. In this work, we used an experimental model of dry eye in rats with the development of inflammation of the anterior surface of the eye. Alkali burns were used to develop inflammation. A fluorescein test performed immediately after alkaline erosion and on days 1, 5, and 10 after burns revealed a gradual increase in corneal epithelialization and vascularization. Results. One day after induction of inflammation, there was a dramatic and statistically significant increase in tear production in experimental rats. By the seventh day, tear production declined to the control level with a subsequent tendency to decrease tear production. Conclusions. In the group of rats with inflammation of the anterior surface of the eye that received polarized red-light therapy, there was no significant decrease in tear production on day 7, which may be indicative of a possible anti-inflammatory effect of light therapy under these conditions.

Efficacy of Repeated Low-Level Red-Light Therapy in Myopia Control in Children: A Multicenter Randomized Controlled Trial

Efficacy of Repeated Low-Level Red-Light Therapy in Myopia Control in Children: A Multicenter Randomized Controlled Trial

A retrospective study comparing different injection approaches of 5-aminolevulinic acid in patients with non-melanoma skin cancer

Background 5-aminolevulinic acid through a needle-free, plum-blossom needle or conventional needle followed by photodynamic therapy are available options for non-melanoma skin cancer treatment. Aim To compare these three techniques of injection of 5-aminolevulinic, regarding treatment response and adverse effects in patients with non-melanoma skin cancer. Patients and methods Non-melanoma skin cancer patients have received six cycles of 0.5 mL intralesional 20% w/v 5-aminolevulinic acid through a conventional needle (CPT cohort, n = 158), or plum-blossom needle (BPT cohort, n = 118), or needle-free injection (NPT cohort, n = 105) followed by irradiation with a red light. Data regarding treatment response and adverse effects were collected and analyzed. Results The treatment response was higher among patients of NPT cohort than those of CPT (p = .012, q = 3.981) and BPT (p = .012, q = 3.472) cohorts. Conventional and plum-blossom needle injections therapies were reported scar, local redness, and worse cosmetic appearance in the follow-up period. Conclusions Needle-free injection of intralesional 5-aminolevulinic acid followed by irradiation with red light therapy were reported high treatment response with manageable adverse effects for non-melanoma skin cancer patients than that of conventional and plum-blossom needle injections. Level of evidence III.

Effects of bright light therapy for depression during pregnancy: a randomised, double-blind controlled trial

ObjectivesApproximately 11%–13% of pregnant women suffer from depression. Bright light therapy (BLT) is a promising treatment, combining direct availability, sufficient efficacy, low costs and high safety for both mother and...

Red-Light (670 nm) Therapy Reduces Mechanical Sensitivity and Neuronal Cell Death, and Alters Glial Responses after Spinal Cord Injury in Rats.

Individuals with spinal cord injury (SCI) often develop debilitating neuropathic pain, which may be driven by neuronal damage and neuroinflammation. We have previously demonstrated that treatment using 670 nm (red) light irradiation alters microglia/macrophage responses and alleviates mechanical hypersensitivity at 7 days post-injury (dpi). Here, we investigated the effect of red light on the development of mechanical hypersensitivity, neuronal markers, and glial response in the subacute stage (days 1-7) following SCI. Wistar rats were subjected to a mild hemi-contusion SCI at vertebra T10 or to sham surgery followed by daily red-light treatment (30 min/day; 670 nm LED; 35 mW/cm2) or sham treatment. Mechanical sensitivity of the rat dorsum was assessed from 1 dpi and repeated every second day. Spinal cords were collected at 1, 3, 5, and 7 dpi for analysis of myelination, neurofilament protein NF200 expression, neuronal cell death, reactive astrocytes (glial fibrillary acidic protein [GFAP]+ cells), interleukin 1 β (IL-1β) expression, and inducible nitric oxide synthase (iNOS) production in IBA1+ microglia/macrophages. Red-light treatment significantly reduced the cumulative mechanical sensitivity and the hypersensitivity incidence following SCI. This effect was accompanied by significantly reduced neuronal cell death, reduced astrocyte activation, and reduced iNOS expression in IBA1+ cells at the level of the injury. However, myelin and NF200 immunoreactivity and IL-1β expression in GFAP+ and IBA1+ cells were not altered by red-light treatment. Thus, red-light therapy may represent a useful non-pharmacological approach for treating pain during the subacute period after SCI by decreasing neuronal loss and modulating the inflammatory glial response.

In vitro anti-breast cancer studies of LED red light therapy through autophagy.

LED red light has been reported to have many health benefits. The present study was conducted to characterise anti-proliferation properties of four LED red light wavelengths (615, 630, 660 and 730nm) against non-triple negative (MCF-7) and triple negative (MDA-MB-231) breast cancer-origin cell lines. It has been shown by MTT assay that at 24h post-exposure time point, only LED red light with wavelength 660nm possessed anti-proliferative effects against both cell lines with 40% reduction of cell viability. The morphology of LED 660nm irradiated cells was found flatten with enlarged cell size, typical characteristic of cell senescent. Indications of autophagy activities following the irradiation have been provided by acridine orange staining, showing high presence of acidic vesicle organelles (AVOs). In addition, high LC3-II/LC3-I to LC3 ratio has been observed qualitatively in Western blot analysis indicating an increase number of autophagosomes formation in LED 660nm irradiated cells compared to control cells. Electron dense bodies observed in these cells under TEM micrographs provided additional support to the above observations, leading to the conclusion that LED 660nm irradiation promoted anti-proliferative activities through autophagy in breast cancer-origin cells. These findings have suggested that LED 660nm might be developed and be employed as an alternative cancer treatment method in future.

Light therapy for multiple sclerosis-associated fatigue: a randomized, controlled phase II trial

Bright white light therapy (LT) can improve fatigue in several disease states but has not been studied in multiple sclerosis (MS). To determine whether controlled home-based LT is feasible, tolerable, and well-adhered to in MS-associated fatigue. A randomized, controlled trial of twice-daily 1-h bright white LT (BWLT) (10,000lx, active arm) versus dim red LT (DRLT) (< 300lx, control arm) was performed. Adults with MS-associated fatigue were enrolled for 10weeks: 2-week baseline, 4-week intervention, 4-week washout. 41 participants were enrolled; 35 were randomized (average age 42years, 80% female; BWLT n = 20; DRLT n = 15). 31 were in the intention to treat analysis. The average duration of LT sessions was similar between groups (BWLT 60.9min, DRLT 61.5min, p = 0.70). The most commonly reported adverse event was headache. There were no events that led to discontinuation. Baseline fatigue was severe in both arms (each 53/63 points on the Fatigue Severity Scale (FSS), p = 0.92). FSS was lower following BWLT (FSS 45.8 post-LT, p = 0.04; 44.9 post-washout, p = 0.02 intra-group compared to baseline FSS) and DRLT (FSS 46.7 post-LT, p = 0.03; 43.9 post-washout, p = 0.002 intragroup compared to baseline FSS). There was no difference between BWLT and DRLT groups in the magnitude of reduction of FSS scores (p = 0.81 after LT; p = 0.77 after washout for between group comparisons). Similarly, MS quality of life metrics improved in both arms but were not significantly different between groups after LT (p = 0.22) or washout. LT is safe, feasible, and well-tolerated in people with MS-associated fatigue. Improvement in both light spectra likely indicates a strong placebo effect for the DRLT group.

Clinical Usefulness of Bright White Light Therapy for Depressive Symptoms in Cancer Survivors: Results from a Series of Personalized (N-of-1) Trials.

Purpose: Little is known about the effectiveness of bright white light therapy (BWL) for depressive symptoms in cancer survivors, many of whom prefer non-pharmacological treatments. The purpose of this study was to compare the effectiveness of BWL versus dim red light therapy (DRL) on depressive symptoms within individual cancer survivors using personalized (N-of-1) trials. Methods: Cancer survivors with at least mild depressive symptoms were randomized to one of two treatment sequences consisting of counterbalanced crossover comparisons of three-weeks of lightbox-delivered BWL (intervention) or DRL (sham) for 30 min each morning across 12 weeks. A smartphone application guided cancer survivors through the treatment sequence and facilitated data collection. Cancer survivors tracked end-of-day depressive symptoms (primary outcome) and fatigue using visual analog scales. Within-patient effects of BWL were assessed using an autoregressive model with adjustment for linear time trends. Results: Eight of nine cancer survivors completed the 12-week protocol. Two survivors reported significantly (i.e., p < 0.05) lower depressive symptoms (−1.3 ± 0.5 and −1.30 ± 0.9 points on a 10-point scale), five reported no difference in depressive symptoms, and one reported higher depressive symptoms (+1.7 ± 0.6 points) with BWL versus DRL. Eight of nine cancer survivors recommended personalized trials of BWL to others. Conclusions: There were heterogeneous effects of three-week BWL on self-reported depressive symptoms among cancer survivors, with some finding a benefit but others finding no benefit or even harm. Implications for Cancer Survivors: Personalized trials can help cancer survivors learn if BWL is helpful for improving their depressive symptoms.

Efficacy of Repeated Low-Level Red-Light Therapy in Myopia Control

Efficacy of Repeated Low-Level Red-Light Therapy in Myopia Control

Metaanalysis of clinical efficacy and tolerability of at-home low-level blue and red light therapy technology in the treatment of mild to moderate acne

Metaanalysis of clinical efficacy and tolerability of at-home low-level blue and red light therapy technology in the treatment of mild to moderate acne