When it comes to wound healing, whether from surgery, injury, or chronic conditions, the search for safe, effective, and non-invasive treatments has led researchers to explore the power of laser therapy. Over the past few decades, studies have consistently demonstrated that low-level laser therapy (LLLT) — also known as photobiomodulation — accelerates healing, reduces scarring, and enhances tissue repair across both animal and human models. In this blog, we’ll dive into the science behind laser therapy for wound healing, drawing on key research to explain how it works, its proven benefits, and why it’s becoming a go-to option in veterinary and clinical settings.

The Basics: How Laser Therapy Supports Wound Healing

Laser therapy works by delivering specific wavelengths of light to damaged tissue, where it interacts with cellular components to trigger biological responses that speed up healing. Unlike high-powered surgical lasers that cut or ablate tissue, low-level lasers (and similar LED devices) use gentle energy to stimulate cells without causing heat or damage. Research highlights several core mechanisms driving these effects:

• Reduced inflammation: Laser light decreases the presence of inflammatory cells, calming the body’s initial immune response to prevent excessive swelling and tissue damage.
• Enhanced cell proliferation: It stimulates fibroblasts (cells that produce collagen) and keratinocytes (skin cells) to multiply, accelerating the formation of new tissue.
• Stimulated angiogenesis: Laser therapy promotes the growth of new blood vessels, improving oxygen and nutrient delivery to the wound site — a critical step for healing.
• Increased collagen synthesis: Collagen is the building block of scar tissue and healthy skin; laser therapy boosts its production and organization, leading to stronger, more cosmetically pleasing results.

These mechanisms aren’t just theoretical — they’re supported by rigorous studies across species and wound types.

Key Research: Laser Therapy Delivers Proven Results

Let’s explore the landmark studies that validate laser therapy’s effectiveness, including the research you’ve shared.

1. Laser Therapy Hastens Surgical Wound Healing in Dogs

A 2019 study published in Frontiers in Veterinary Science (Wardlaw et al., 2018; DOI: 10.3389/fvets.2018.00349) tested laser therapy on 12 Dachshunds that underwent thoracolumbar hemilaminectomies (spinal surgery) for intervertebral disc disease (IVDD). The researchers developed a standardized scar scale (ranging from 0 = fresh incision to 5 = fully healed with hair growth) to assess healing over 21 days.

Nine dogs were randomly assigned to either receive daily 8 J/cm² laser therapy for 7 days or serve as a non-laser control group. The results were striking:

• By day 7, laser-treated dogs had significantly higher scar scale scores, indicating faster cosmetic healing.
• By day 21, the laser group showed complete healing with scar contraction and hair regrowth, while control dogs still had scabs or wide scar areas.
• Inter-rater reliability was excellent (p = 0.9), confirming the consistency of the findings.

This study is particularly noteworthy because it demonstrates laser therapy’s effectiveness in a clinical setting for surgical wounds — a common application in veterinary medicine, where post-operative healing is critical for patient recovery.

2. LED vs. Laser: Similar Biological Effects for Wound Healing

While lasers are often the focus, a 2014 review in Anais Brasileiros de Dermatologia (Chaves et al., 2014; DOI: 10.1590/abd1806-4841.20142519) compared low-power laser and LED therapy, finding that both deliver comparable benefits for wound healing. The researchers analyzed 68 in vitro and animal studies published between 1992 and 2012, concluding that:

• Both LED and laser therapy reduce inflammatory cells, stimulate fibroblast proliferation, boost angiogenesis, and increase collagen synthesis.
• The biological effects depend on key parameters like wavelength and dose — not the type of light device (laser vs. LED).

This review is valuable for understanding that laser therapy is part of a broader category of low-level light therapies, all of which leverage light’s ability to modulate cellular activity. It also emphasizes the importance of standardizing parameters (e.g., dose, wavelength) for optimal results — a key consideration for clinical use.

3. Meta-Analysis: Laser Therapy Is Effective Across Species

A 2004 meta-analysis in Photomedicine and Laser Surgery (Woodruff et al., 2004; DOI: 10.1089/1549541041438623) aggregated data from 24 studies (including both animal and human research) to quantify laser therapy’s overall effect on wound healing. Using Cohen’s d statistic to measure treatment effect size, the researchers found:

• An overall effect size of d = +2.22, indicating a highly significant positive impact on wound healing.
• Significant benefits in both animal experiments (d = +1.97) and human clinical studies (d = +0.54).
• Specific improvements in key healing markers: acceleration of inflammation (d = +4.45), increased collagen synthesis (d = +1.80), enhanced tensile strength (d = +2.37), reduced healing time (d = +3.24), and smaller wound size (d = +0.55).

The study also calculated a “fail-safe number” of 509, meaning 509 additional studies showing no benefit of laser therapy would be needed to negate the observed effects — a testament to the robustness of the findings.

4. Targeted Light Therapy: Red and Blue Light for Healing and Scar Reduction

A 2024 study in Communications Biology (Deng et al., 2024; PMC11452386) delved deeper into the mechanisms of light therapy, focusing on red (630 nm) and blue (450 nm) light’s effects on wound healing and scar formation in mice. The researchers discovered that:

• Red light activates the PI3Kβ/STAT3 signaling pathway, promoting keratinocyte and fibroblast proliferation, accelerating wound healing, but potentially increasing scar formation.
• Blue light inhibits STAT3 phosphorylation via reactive oxygen species (ROS) production, reducing scar formation but slowing healing.
• Sequential therapy (red light first to heal, then blue light to reduce scarring) achieved the best of both worlds: faster healing and minimal scarring.

While this study focuses on LED-based light therapy, it reinforces the broader principle that light (including laser light) can be tailored to target specific stages of healing. For laser therapy, this suggests that adjusting parameters like wavelength could optimize both healing speed and cosmetic outcomes.

Who Can Benefit from Laser Therapy for Wound Healing?

Laser therapy’s versatility makes it suitable for a wide range of wound types and patients:

• Veterinary patients: As shown in Wardlaw et al.’s study, laser therapy is ideal for post-surgical wounds in dogs, cats, and other animals, reducing recovery time and improving outcomes.
• Humans with acute wounds: Surgical incisions, lacerations, and burns can heal faster with laser therapy, minimizing scarring and reducing the risk of infection.
• Chronic wound patients: Those with non-healing wounds (e.g., diabetic ulcers, pressure sores) may benefit from laser therapy’s ability to stimulate stagnant healing processes.

Considerations for Using Laser Therapy

While the research is promising, successful laser therapy depends on two key factors:

1. Parameter standardization: As highlighted in Chaves et al.’s review, dose (e.g., 8 J/cm² in Wardlaw et al.’s study) and wavelength must be tailored to the wound type and patient. Too low a dose may have no effect, while too high a dose could cause tissue damage.
2. Timing and frequency: Daily treatments (as in Wardlaw et al.) or sequential therapy (as in Deng et al.) may be necessary to maximize benefits, depending on the wound’s stage of healing.

Conclusion: Laser Therapy Is a Science-Backed Tool for Wound Healing

The research is clear: laser therapy (and low-level light therapy more broadly) is an effective, non-invasive option for accelerating wound healing, reducing scarring, and improving tissue repair. From surgical wounds in dogs to chronic ulcers in humans, studies consistently demonstrate its ability to modulate cellular activity, reduce inflammation, and boost key healing processes.

Whether you’re a veterinarian looking to optimize post-operative care, a healthcare provider treating human patients, or someone seeking faster recovery from a wound, laser therapy offers a safe and evidence-based solution. As research continues to refine parameters and uncover new mechanisms, it’s likely to become an even more integral part of wound care in the years to come.

References:

1. Wardlaw, J. L., Gazzola, K. M., Wagoner, A., et al. (2019). Laser Therapy for Incision Healing in 9 Dogs. Frontiers in Veterinary Science, 6, 349. https://doi.org/10.3389/fvets.2018.00349
2. Chaves, M. E. A., Araújo, A. R., Piancastelli, A. C. C., et al. (2014). Effects of low-power light therapy on wound healing: LASER x LED. Anais Brasileiros de Dermatologia, 89(4), 616–623. https://doi.org/10.1590/abd1806-4841.20142519
3. Woodruff, L. D., Bounkeo, J. M., Brannon, W. M., et al. (2004). The efficacy of laser therapy in wound repair: a meta-analysis of the literature. Photomedicine and Laser Surgery, 22(3), 241–247. https://doi.org/10.1089/1549541041438623
4. Deng, F., Yang, R., Yang, Y., et al. (2024). Visible light accelerates skin wound healing and alleviates scar formation in mice by adjusting STAT3 signaling. Communications Biology, 7, 1266. https://doi.org/10.1038/s42003-024-06973-1