Nair H.K.R. et al. - Photobiomodulation as an adjunct in the healing of chronic ulcers

In a series of 11 patients with chronic wounds, photobiomodulation added to standard care resulted in complete wound healing and significant reductions in wound area. This was a case series without a control group or randomization, which precludes attributing these outcomes to the light therapy.

What this study measured

This study is a case series conducted in the wound care unit of a hospital in Kuala Lumpur; it is neither a randomized controlled trial nor a meta-analysis. Eleven patients with chronic wounds of various etiologies were included: 9 diabetic foot ulcers and 2 non-healing ulcers.

The criterion used was wound size, assessed by its length and width—that is, by surface area. The wounds were assessed before being cleaned with distilled water and then washed if necessary. The light therapy protocol combined three wavelengths—660, 800, and 970 nm—delivered as a continuous beam with 30 kJ of energy over a 3-minute period, with the handpiece centered on the wound and then moved around the area surrounding the wound. All wounds were also managed according to standard of care.

Key Findings

The reported trends are positive but purely descriptive.

• 11 patients were included, including 9 with diabetic foot ulcers and 2 with non-healing ulcers
• Complete closure was reported in 3 cases of diabetic foot ulcers and 1 case of a non-healing ulcer
• A reduction in surface area ranging from 68.2% to 99% for the other 7 ulcers
• The appearance of granulation tissue, interpreted by the authors as indicating a high potential for healing
• No statistical comparisons, no confidence intervals, no p-values

It should be noted that there is an internal inconsistency in the abstract: it mentions three closed wounds but then lists four. The authors themselves conclude that a larger sample size would be necessary to determine the scope of these findings.

How photobiomodulation works for this indication

The proposed mechanisms for wound healing remain hypothetical. The absorption of red and near-infrared light by mitochondrial cytochrome c oxidase may increase the production of ATP available to repair cells. Modulation of local inflammation, stimulation of angiogenesis, and activation of fibroblast proliferation and migration are also proposed as explanations for granulation tissue formation. This case series did not measure any of these biological parameters.

Limits You Should Know

The key limitation is the absence of a control group: the wounds also received standard care, so the observed outcomes could be attributed to that care, the natural history of the wounds, or the light therapy, without it being possible to determine the cause. The result is therefore, in terms of evidence, inconclusive.

Additional limitations include a very small sample size, the lack of a blind design, a heterogeneous study population, the absence of a specified follow-up period in the abstract, and the lack of data on adverse effects. This is a single, single-center study.

An important reminder: Chronic ulcers, particularly those associated with diabetic foot, require specialized medical care. Photobiomodulation is not a substitute for treating the underlying cause—whether venous, arterial, or diabetic—nor does it replace offloading, local care, or metabolic control.

What This Means in Practice

These findings suggest that photobiomodulation may be a potential adjunct to conventional care, to be evaluated in controlled trials. They do not justify any changes to a wound care protocol established by a healthcare team. Any chronic wound that is not healing should be reevaluated by a physician.

Frequently Asked Questions

Does this study prove that light accelerates healing?

No. Without a control group, it is impossible to know what would have happened to the same wounds if they had received only standard care. The study describes favorable outcomes, which justifies further research, but does not demonstrate a cause-and-effect relationship.

Can photobiomodulation replace treatment for a chronic ulcer?

No, and the study itself classifies it as an adjunctive therapy. All of the wounds included in the study continued to receive standard care. Treating the underlying cause—whether venous, arterial, or diabetic—remains the priority and is the responsibility of a specialized team.

What lighting settings were used?

The abstract specifies three combined wavelengths—660, 800, and 970 nm—a continuous energy flux of 30 kJ, and a 3-minute application to the wound and the surrounding area. Other parameters, including the frequency and total number of sessions, are not specified in the abstract.

Reference

Nair HKR, Chong SSY, Selvaraj DDJ. Photobiomodulation as an Adjunct Therapy in Wound Healing. The International Journal of Lower Extremity Wounds, 2021;22(2):278-282. PMID 33973828. DOI 10.1177/15347346211004186. https://doi.org/10.1177/15347346211004186

This summary is provided for informational purposes only and does not constitute medical advice. Photobiomodulation is not a substitute for prescribed treatment. Consult a healthcare professional.