Photobiomodulation with low-level laser (LLLT) in the treatment of wounds

Photobiomodulation is a term used to describe treatments with lasers or other LEDs. A common method in the field of photobiomodulation is low-level laser or low-level laser therapy (LLLT). Wound healing was one of the first areas where low-power lasers were tested, but the method has also been used to reduce pain, inflammation and swelling.


What systematic reviews are there on the effect of low-level laser therapy?

Identified literature

Table 1. Systematic reviews with low/medium risk of bias
RCT = Randomised controlled trial; LLLT = Low level laser therapy; nm = Nanometre; cm2 = Square centimetres; J = Joule; W = Watt; SMD = Standardized mean difference; CI = Confidence interval; SD = Standard deviation; RR = Risk ratio
Included studies Population/Intervention Outcome and Results
Huang et al, 2021, [1]
Study design: Randomized controlled trials (RCTs).
Included: n=13 RCTs
Countries: India (n=2), Iran (n=2), Israel (n=1), Brazil (n=2), Colombia (n=1), and China (n=5).
Risk for bias:Moderaterisk of bias
Population: Patients with diabetic foot ulcers. Five on type 2 diabetes.
Severity of ulcer from Wagner I to Wagner III
Mean age: 48.33 to 68.50 years

Intervention: LLLT

Setting: Not specified
Complete healing rate (9 RCTs, n=278):
RR 2.10 (95% CI, 1.56 to 2.83)
GRADE: Very Low

Ulcer area reduction percentage (5 RCTs, n=166):
SMD 3.52 (95% CI, 1.65 to 5.38)

Mean healing time (2 RCTs, n=80):
SMD –1.40 (95% CI, –1.90 to –0.91)

Adverse effect:
None observed in 7 studies
Data not available from 6 studies
Authors' conclusion:
“This meta-analysis demonstrates that LLT is a promising and effective treatment for DFUs. Further evidence from larger samples and higher quality RCTs is needed to prove the effect of LLLT and to determine the most appropriate parameters for the healing of DFUs.”
Zhou et al, 2021, [2]
Study design: Randomized controlled trials (RCTs).
Control was either usual care with or without placebo lights.
Included: n=12 RCTs
Countries: India (n=3), Iran (n=2), Brazil (n=2), Slovenia (n=1), Israel (n=1), Malaysia (n=1), Colombia (n=1), and China (n=1).
Risk for bias: Low risk for bias
Population: Patients with diabetic foot ulcers.
Mean age: 45 to 64.85 years

Intervention: LLLT. Defined as wavelengths ranging from 500 to 1100 nm, energy densities between 0.1 and 10 J/cm2 and power ranging from 0.01 to 0.5 W/cm2.

Setting: At hospital (n=11), at home (n=1).
Mean initial ulcer size: 1.83 to 62.9 cm2.
Mean duration of ulcer: 5 days to 95.5 months.
Reduction (%) of wound ulcer size (6 RCTs, n=235)
30.89% (95% CI, 15.60 to 46.18), p<0.001
Hedges’ g=2.81
SMD: 2.80 SD higher (95% CI, 1.09 to 4.51 higher)
GRADE: Very low (Symbol for very low certainty of evidence).
Reduction (cm2) of wound ulcer size (5 RCTs, n=232)
4.20 cm2 (95% CI, 0.41 to 7.99), p=0.03)
Hedges’ g: 1.37
SMD: 1.37 SD higher (95% CI, 0.30 to 2.44 higher)
GRADE: Very low (Symbol for very low certainty of evidence).
Complete wound healing rate (5 RCTs, n=221)
RR: 4.65 (95% CI, 1.89 to 11.46)
GRADE: Low (Symbol for low certainty of evidence).
Authors' conclusion:
“Low-level light therapy had shown promising results for diabetic foot ulcers in accelerated ulcer healing and effectively reduced ulcer sizes. Subgroup findings revealed the high efficacy of low-level light therapy on diabetic foot ulcers of different sizes. However, due to the limited body of evidence in terms of sample size in this meta-analysis, results were interpreted with caution. Low-level light therapy can be used as an adjunct therapy. Future investigation could explore optimal conditions, settings, and regimes of therapy for diabetic foot ulcers. This review also urges researchers to adhere to the CONSORT guidelines in future studies to strengthen the quality of trials.”
Lucas et al, 2000, [3]
Study design: Randomized controlled trials (RCTs).
Control was either placebo or ultrasound/ultraviolet treatment.
Included: n=4 RCT

Countries: Canada, Sweden, Israel, Australia.

Risk for bias: Moderate risk for bias
Population: Patients with topical ulcerations or wounds.

Intervention: Infrared LLLT, defined as 820 to 950 nm.
Patients with poor outcome (wound still open at study end)
RR 0.76 (95% CI, 0.41 to 1.40)
Authors' conclusion:
“At present, we conclude that there are no scientific arguments for routine application of low level (infrared) laser therapy on wound healing in patients with decubitus ulcers, venous leg ulcers (ulcus cruris) or other chronic wounds”


Table 2. Relevant studies which were identified through the reviews with high risk for bias.
Population Wavelength (nm) Comparison
Vitoriano et al
DFU 830 & 850 LLLT vs other laser
Tantawy et al
DFU 632 & 904 LLLT vs other laser
Maiya et al
DFU 660, 633 & 850 LLLT, without control
Srilestari et al
DFU 630 LLLT vs placebo
Afify et al
DFU 904 LLLT vs alternative
Salvi et al
DFU 415, 633 & 830 LLLT on DFU vs healthy control
Carvalho et al
DFU 658 LLLT vs alternative
Feitosa et al
DFU 632.8 LLLT vs usual care
Taradaj et al
PU 980, 808 & 658 LLLT vs placebo
Shojaei et al
PU 940, 808 & 658 LLLT vs placebo
Taly et al
PU 820 LLLT vs placebo
Lucas et al
PU 904 LLLT vs usual care
DFU = Diabetic foot ulcer; PU = Pressure Ulcer


  1. Huang J, Chen J, Xiong S, Huang J, Liu Z. The effect of low-level laser therapy on diabetic foot ulcers: A meta-analysis of randomised controlled trials. Int Wound J 2021.
  2. Zhou Y, Chia HWA, Tang HWK, Lim SYJ, Toh WY, Lim XL, et al. Efficacy of low-level light therapy for improving healing of diabetic foot ulcers: A systematic review and meta-analysis of randomized controlled trials. Wound Repair Regen 2021;29:34-44.
  3. Lucas C, Stanborough RW, Freeman CL, De Haan RJ. Efficacy of Low-Level Laser Therapy on Wound Healing in Human Subjects: A Systematic Review. Lasers Med Sci 2000;15:84-93.
  4. Vitoriano NAM, Mont'Alverne DGB, Martins MIS, Silva PS, Martins CA, Teixeira HD, et al. Comparative study on laser and LED influence on tissue repair and improvement of neuropathic symptoms during the treatment of diabetic ulcers. Lasers Med Sci 2019;34:1365-1371.
  5. Tantawy SA, Abdelbasset WK, Kamel DM, Alrawaili SM. A randomized controlled trial comparing helium-neon laser therapy and infrared laser therapy in patients with diabetic foot ulcer. Lasers Med Sci 2018;33:1901-1906.
  6. Maiya AG, Kumar AS, Hazari A, Jadhav R, Ramachandra L, Hande HM, et al. Photobiomodulation therapy in neuroischaemic diabetic foot ulcers: a novel method of limb salvage. J Wound Care 2018;27:837-842.
  7. Srilestari A, Nareswari I, Simadibrata CL, Tarigan TJE. Effectiveness of combined laser-puncture and conventional wound care to accelerate diabetic foot ulcer healing. Medical Journal of Indonesia 2017;26:26-34.
  8. Afify N, Rasheed A, Fekry N, Hamada H, El Khatib A. Pulsed electromagnetic fields versus laser therapy on enhancing recovery of diabetic foot ulcer- A single blind randomized controlled trial. Biomedical Research 2017;28.
  9. Salvi M, Rimini D, Molinari F, Bestente G, Bruno A. Effect of low-level light therapy on diabetic foot ulcers: a near-infrared spectroscopy study. J Biomed Opt 2017;22:38001.
  10. Carvalho AF, Feitosa MC, Coelho NP, Rebelo VC, Castro JG, Sousa PR, et al. Low-level laser therapy and Calendula officinalis in repairing diabetic foot ulcers. Rev Esc Enferm USP 2016;50:628-634.
  11. Feitosa MC, Carvalho AF, Feitosa VC, Coelho IM, Oliveira RA, Arisawa EA. Effects of the Low-Level Laser Therapy (LLLT) in the process of healing diabetic foot ulcers. Acta Cir Bras 2015;30:852-7.
  12. Taradaj J, Halski T, Kucharzewski M, Urbanek T, Halska U, Kucio C. Effect of Laser Irradiation at Different Wavelengths (940, 808, and 658 nm) on Pressure Ulcer Healing: Results from a Clinical Study. Evid Based Complement Alternat Med 2013;2013:960240.
  13. Shojaei H, Sokhangoei Y, Soroush M. Low level laser therapy in the treatment of pressure ulcers in spinal cord handicapped veterans living in Tehran. 2008;33:44-48.
  14. Taly AB, Sivaraman Nair KP, Murali T, John A. Efficacy of multiwavelength light therapy in the treatment of pressure ulcers in subjects with disorders of the spinal cord: A randomized double-blind controlled trial. Arch Phys Med Rehabil 2004;85:1657-61.
  15. Lucas C, van Gemert MJ, de Haan RJ. Efficacy of low-level laser therapy in the management of stage III decubitus ulcers: a prospective, observer-blinded multicentre randomised clinical trial. Lasers Med Sci 2003;18:72-7.

SBU Enquiry Service Consists of structured literature searches to highlight studies that can address questions received by the SBU Enquiry Service from Swedish healthcare or social service providers. We assess the risk of bias in systematic reviews and when needed also quality and transferability of results in health economic studies. Relevant references are compiled by an SBU staff member, in consultation with an external expert when needed.

Published: 11/24/2021
Report no: ut202125
Registration no: SBU 2021/300