Far Red Light Therapy for Peripheral Arterial Disease

(LIGHT PAD Trial)

Overseen By Mary McDermott, MD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Northwestern University

Disqualifiers: Amputation, Critical limb ischemia, Wheelchair, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

Duration: 16 weeks

32 Participants Needed

Trial Summary

What is the purpose of this trial?

The LIGHT PAD Trial is a Phase II multi-centered randomized clinical trial to collect preliminary data to test whether daily far red light treatment of the lower extremities in people with PAD improves six-minute walk distance, lower extremity perfusion, and ischemia-related damage in gastrocnemius muscle at four-month follow-up, compared to a sham control. Participants will complete 10 minutes of twice daily home treatment with either far red light or a sham light for four months.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It is best to discuss this with the trial coordinators or your doctor.

What data supports the effectiveness of Far Red Light Therapy for Peripheral Arterial Disease?

Research shows that light therapy, including red and near-infrared light, can increase blood flow by generating nitric oxide, which helps widen blood vessels. This effect has been observed in studies involving both animals and humans, suggesting potential benefits for conditions like Peripheral Arterial Disease where improved circulation is needed. ^{1 2 3 4 5}

Is Far Red Light Therapy safe for humans?

Far Red Light Therapy, also known as low-level laser therapy, has been used safely in various medical fields like dentistry, physiotherapy, and cardiology for over forty years. It is generally considered safe, with studies showing positive effects on healing and reducing inflammation, although the exact mechanisms are not fully understood. ^{3 6 7 8 9}

How does Far Red Light Therapy differ from other treatments for Peripheral Arterial Disease?

Far Red Light Therapy is unique because it uses light to improve blood flow and stimulate healing, unlike traditional medical or surgical treatments. This therapy, known as photobiomodulation, can be self-administered and has no reported side effects, making it a novel approach for managing conditions like Peripheral Arterial Disease. ^{1 2 3 4 10}

Eligibility Criteria

This trial is for people over 50 with Peripheral Arterial Disease (PAD), evidenced by specific tests. They must be able to walk without a walker or wheelchair, not have critical limb ischemia, recent major surgeries, severe medical conditions like advanced lung disease or Parkinson's, and should not be in another clinical trial recently.

Inclusion Criteria

I am 50 years old or older.

I have been diagnosed with PAD based on specific tests and criteria.

Exclusion Criteria

I haven't had major surgery or significant heart issues in the last 3 months.

My walking is limited by a condition that is not related to leg artery disease.

I am scheduled for major surgery or heart/leg artery treatment in the next 4 months.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive daily far red light treatment or sham control for four months

16 weeks

Home treatment, twice daily

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

Treatment Details

Interventions

• Far Red Light Therapy
• Sham Light Therapy

Trial Overview The LIGHT PAD Trial is testing if far red light therapy can improve walking distance and blood flow in the legs of PAD patients compared to a fake light treatment. Participants will use the assigned light device on their lower extremities at home for ten minutes twice daily over four months.

Participant Groups

Group I: Far red light therapy Experimental Treatment 1 Intervention

Subgroup of participants receiving the 670 nm far red light device

Group II: Sham therapy Placebo Group 1 Intervention

Subgroup of participants receiving the sham light device, far red light device covered with blue filter paper to block 670 nm light, resulting in mean power generated of 0.24 mW/cm2, compared to 26.3 mW/cm2 for the intervention, a 100-fold difference.

Who Is Running the Clinical Trial?

Northwestern University

Lead Sponsor

Trials

1,674

Recruited

989,000+

Findings from Research

Photobiomodulation, or light therapy using low-energy red lasers, shows promise for treating a variety of medical conditions, including neurological issues like stroke and traumatic brain injury, as well as pain management and skin conditions.

The mechanisms of action for photobiomodulation are still not fully understood, but research indicates that red lasers can penetrate the skull, suggesting potential therapeutic effects on brain function.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Perspective on Broad-Acting Clinical Physiological Effects of Photobiomodulation. Shanks, S., Leisman, G.[2019]

Low-level laser therapy (LLLT) significantly increased nitric oxide (NO) levels in the venous blood of 15 healthy subjects, indicating its potential efficacy in enhancing blood flow.

The peak increase in NO occurred 5 minutes after treatment, suggesting that LLLT may be effective shortly after application, although further studies are needed to evaluate its effects in patients with medical conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Low-level laser treatment with near-infrared light increases venous nitric oxide levels acutely: a single-blind, randomized clinical trial of efficacy. Mitchell, UH., Mack, GL.[2016]

Far-infrared (FIR) therapy can enhance skin microcirculation in rats through a mechanism that does not rely on thermal effects, as evidenced by significant increases in blood flow after FIR treatment was stopped.

The study suggests that FIR therapy works by promoting the production of nitric oxide (NO), which is crucial for blood flow regulation, indicating its potential clinical use for treating ischemic conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Biological effect of far-infrared therapy on increasing skin microcirculation in rats. Yu, SY., Chiu, JH., Yang, SD., et al.[2022]

In a study involving 48 male cyclists, the combination of infrared and red photobiomodulation therapy showed a significant positive effect on performance metrics like total time to exhaustion and VO2max, suggesting that using both wavelengths together may enhance athletic performance.

While no significant differences were found in most performance measures, moderate to large effect sizes were observed in specific areas, indicating that while PBMT alone may not improve performance, the combination of wavelengths could be beneficial when applied correctly.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Photobiomodulation by light emitting diode applied sequentially does not alter performance in cycling athletes. de Carvalho, G., Gobbi, A., Gobbi, RB., et al.[2020]

Irradiating the hind limb of mice with red light (670 nm) for 5-10 minutes significantly increased blood flow by promoting the release of a nitric oxide precursor, demonstrating its potential for enhancing vasodilation in ischemic tissues.

In a model simulating human peripheral artery disease, repeated light treatment over 14 days led to a sustained increase in blood flow in the affected limb, suggesting that this therapy could be a simple and effective home-based treatment for individuals with impaired blood circulation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

In Vivo Characterization of a Red Light-Activated Vasodilation: A Photobiomodulation Study. Keszler, A., Lindemer, B., Broeckel, G., et al.[2023]

Low-level light therapy (photobiomodulation) shows promising benefits in periodontal and dental implant treatments, including enhanced healing and reduced inflammation, based on a review of various studies.

Despite the positive effects observed, there is significant variability in study designs and light irradiation parameters, making it difficult to establish standardized evidence-based treatment protocols for clinical practice.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Photobiomodulation in Periodontology and Implant Dentistry: Part 2. Gholami, L., Asefi, S., Hooshyarfard, A., et al.[2020]

Both low-level laser therapy and LED light sources can effectively induce vasodilation in porcine coronary arteries, with maximum relaxation observed at an energy density of 10 J/cm², achieving comparable results between the two light sources.

The vasodilation effect is mediated by a nitric oxide-dependent mechanism, suggesting that these light therapies could be beneficial in clinical settings, such as during coronary artery bypass surgery, to facilitate easier suturing of blood vessels.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Light-induced vasodilation of coronary arteries and its possible clinical implication. Plass, CA., Loew, HG., Podesser, BK., et al.[2015]

Low-level laser therapy (LLLT) has been shown to effectively reduce pain, inflammation, and promote healing, but its acceptance in mainstream medicine is hindered by incomplete understanding of its biochemical mechanisms and varying results from studies.

A biphasic dose response is observed in LLLT, where lower levels of light are more effective for tissue stimulation and repair compared to higher levels, which aligns with the Arndt-Schulz curve concept.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Biphasic dose response in low level light therapy. Huang, YY., Chen, AC., Carroll, JD., et al.[2023]

Low-level laser therapy (LLLT) utilizes the unique properties of low-energy laser radiation to promote healing and reduce pain, making it a versatile treatment option in various medical fields such as regenerative medicine, dentistry, and physiotherapy.

LLLT is effective in applications like wound healing, scar improvement, and pain reduction, demonstrating its potential as a safe and non-invasive therapeutic method in both clinical practice and research.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Use of Low-Level Energy Laser Radiation in Basic and Clinical Research. Rola, P., Doroszko, A., Derkacz, A.[2019]

An 84-year-old woman with type 2 diabetes successfully healed a 1 cm ulcer on her leg using self-administered photobiomodulation therapy (PBM) with the B-Cure Laser Pro, showing complete healing after 30 days.

This case suggests that PBM therapy could be a safe and effective treatment option for managing leg ulcers in diabetic patients, potentially reducing the need for more invasive procedures like amputation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Auto-Administered Photobiomodulation on Diabetic Leg Ulcers Treatment: A New Way to Manage It? Merigo, E., Tan, L., Zhao, Z., et al.[2022]

References

1. United States pubmed.ncbi.nlm.nih.gov

Perspective on Broad-Acting Clinical Physiological Effects of Photobiomodulation. [2019]

2. United States pubmed.ncbi.nlm.nih.gov

Low-level laser treatment with near-infrared light increases venous nitric oxide levels acutely: a single-blind, randomized clinical trial of efficacy. [2016]

3. England pubmed.ncbi.nlm.nih.gov

Biological effect of far-infrared therapy on increasing skin microcirculation in rats. [2022]

4. England pubmed.ncbi.nlm.nih.gov

Photobiomodulation by light emitting diode applied sequentially does not alter performance in cycling athletes. [2020]

5. Switzerland pubmed.ncbi.nlm.nih.gov

In Vivo Characterization of a Red Light-Activated Vasodilation: A Photobiomodulation Study. [2023]

6. United States pubmed.ncbi.nlm.nih.gov

Photobiomodulation in Periodontology and Implant Dentistry: Part 2. [2020]

7. Netherlands pubmed.ncbi.nlm.nih.gov

Light-induced vasodilation of coronary arteries and its possible clinical implication. [2015]

8. United States pubmed.ncbi.nlm.nih.gov

Biphasic dose response in low level light therapy. [2023]

9. Poland pubmed.ncbi.nlm.nih.gov

The Use of Low-Level Energy Laser Radiation in Basic and Clinical Research. [2019]

10. United States pubmed.ncbi.nlm.nih.gov

Auto-Administered Photobiomodulation on Diabetic Leg Ulcers Treatment: A New Way to Manage It? [2022]