[Mise à jour du 11/08/2021]
Burns: light therapy could speed up healing
Published June 28, 2021 in the journal Scientific Reports, a scientific study highlights a new potential benefit of light therapy. Led by a team of researchers from the University of Buffalo, this suggests that this therapy would accelerate the healing of burns.
The study focused on photobiomodulation therapy, a form of low-dose light therapy able to relieve pain and promote tissue regeneration. The study measured the effect of photobiomodulation on third-degree burn closure over a nine-day period in mice. The treatment triggered the activation of a protein, endogenous TGF-beta 1, which stimulated several types of cells involved in the healing process, especially fibroblasts, the main cells of connective tissue, and macrophages, immune cells that reduce inflammation, clean cell debris and fight infections.
“Photobiomodulation therapy has been used effectively in the supportive care of cancer, age-related macular degeneration and Alzheimer’s disease,” commented Praveen Arany, co-author of the study, in a communicated. “A common feature of these conditions is the central role of inflammation. This work provides evidence for the ability of photobiomodulation-activated TGF-beta 1 to attenuate inflammation, while promoting tissue regeneration using a transgenic burn model, ”added the researcher.
According to the authors, these results could lead to a new treatment for burns, which affect more than 6 million people worldwide each year.
All about light therapy
Light therapy consists of exposing yourself to a lamp that reproduces natural sunlight. Its benefits against seasonal depression are recognized.
Origin of light therapy
In 1903, the Danish doctor Ryberg Finsen received the Nobel Prize in medicine for his research on the effect of light radiation on certain diseases, including tuberculosis. However, after the discovery of penicillin and vaccination, light therapy fell into oblivion.
It was not until 1984 that American doctors used it in the treatment of seasonal depression. Following numerous experiments, the benefits of light therapy were officially recognized across the Atlantic in 2005.
In France, the High Authority of Health (HAS) recognizes the benefits of light therapy for seasonal depression and its recurrences in a report published in 2007. This report was however suspended in 2011, as were six other reports published before 2010. This suspension follows the decision of the HAS to manage the conflicts of interest of the experts in order to ensure the quality of the information.
Principle of light therapy
Light therapy is a form of phototherapy that involves exposing yourself to a lamp that reproduces natural sunlight. The intensity of the lamp must be between 2,500 and 10,000 lux (unit of illumination) to be effective. Upon exposure, the retina via neurotransmitters would inhibit melatonin, a hormone normally secreted in the evening before falling asleep.
From September until March, the days get shorter and the light goes down. Our body would then secrete more melatonin during the day. This increase would result in a decrease in vitality which could eventually lead to seasonal depression in the most sensitive subjects.
By exposure to artificial light that recreates the light conditions of the sun, light therapy would slow down the secretion of melatonin. The person would find more energy.
Why do light therapy sessions?
According to the HAS, light therapy, coupled with the use of a dawn simulator, has shown its effectiveness in the treatment of seasonal depression.
According to the researchers, she would also have shown an interest in general depression, sleep disorders, jet lag or night work. The wake / sleep cycles would indeed be resynchronized thanks to this exposure to the hours of the day, and more particularly in the morning when waking up.
How do you practice light therapy?
Initially, light therapy was only practiced in medical centers, wellness centers and hospitals. For practical reasons, it is now possible to recreate at home the conditions for a light therapy session.
There are thus two main types of light therapy devices:
– lamps and light therapy panels are the traditional devices of light therapy. They often come in the form of a light panel or lamp. The person is preferably exposed in the early morning, for 20 to 30 minutes, in front of the light of this lamp, while going about occupations such as reading, listening to music or working on the computer;
– light therapy glasses are in the form of over-glasses; they allow people who do not have enough time to stay in front of lamps to benefit from light therapy treatments. They are particularly suitable for travel to remove the effects of jet-lag (jet lag), as well as night workers.
The dawn simulator is not a light therapy device. However, it has been shown to be effective in the treatment of seasonal depression as well as light therapy lamps. It is particularly useful for reprogramming the biological clock on the wake / sleep cycles. It comes in the form of an alarm clock that diffuses a light of progressive intensity to wake the person from his sleep, gently and without stress.
Contraindications to light therapy
Light therapy is contraindicated in people taking photosensitizing treatment or increasing the sensitivity of the eyes to light. It is also contraindicated in the event of eye problems (cataracts, macular degeneration, glaucoma, retinitis pigmentosa) or diseases affecting the retina (diabetes, herpes, etc.).
Certain mental illnesses (paranoia, schizophrenia, etc.) do not allow treatment in light therapy to be considered.
Before starting light therapy sessions, consultation with a general practitioner, an ophthalmologist or a psychiatrist (as part of the management of depression) is strongly recommended.
How does a light therapy session take place?
The person sits comfortably in front of a light therapy lamp set to a minimum of 2,500 lux. The recommended use is generally an intensity of 10,000 lux at 30 cm from the face, the equivalent of a summer sun. In order to facilitate the absorption of light by the retina, it is imperative to keep your eyes open throughout the session and to install the lamp slightly above the eye line.
During a light therapy session, it is not necessary to stop your activities. It is possible to read or to continue working without problem, provided that you do not make long journeys.
Light therapy sessions are practiced at any time of the day, although the morning sessions are more effective in the treatment of seasonal depression. The practice of light therapy in the evening is reserved only for people with jet lag or who tend to fall asleep too early and wake up too early.
It is preferable to accompany the light therapy sessions with a change in your lifestyle. This is an opportunity to get back to a sporting activity and increase your outings outdoors.
How to choose your light therapy lamp?
Before any light therapy treatment, it is recommended to consult a doctor. They can also advise you on the appropriate type of lamp.
It is better to choose a high brightness lamp of around 10,000 lux to have shortened exposure times. However, lower wattage lamps can be used longer for reading or working. With this in mind, a lamp with a dimmer remains a good choice.
Considered as a medical device, the light therapy lamp must bear the CE medical equipment marking (93/42 / EEC).
As for the wellness centers that provide light therapy sessions, be aware that there is no specific training or label. It is therefore necessary to ensure that the lamps offered meet official standards.
Duration and price of a light therapy session
The duration of exposure to a light therapy device depends on the person’s needs and the light output. Generally, a two-hour session at 2,500 lux or a 30-minute session at 10,000 lux should be scheduled daily for 7 to 10 days.
A light therapy session costs around 15 euros in a wellness center; a light therapy lamp, between 150 and 500 euros depending on its design.
Whether they take place in a wellness center, hospital or medical center, light therapy sessions are not reimbursed by Social Security. The treatment is covered by certain mutuals as part of a consultation in a hospital environment. Home light therapy devices are not reimbursed either.
Books on light therapy
– “Thirst for light. Light therapy: a solution to seasonal depression “, Dr Norman E. Rosenthal and Gérard Pons, eds. Jouvence: a book that clarifies the practice of light therapy and helps to understand its therapeutic applications.
– “The benefits of light on your health “, Fabio Marchesi, ed. Du Dauphin: an Italian engineer and researcher explains how light influences our health from the very first moments of life.
– “Light. Medicine of the future “, Jacob Liberman, ed. The Courier du Livre.
Internet sites dedicated to light therapy
-, French-speaking society of chronobiology
Source: “Report on the management of the progressive complications of a characterized depressive episode in adults”, HAS professional recommendations, April 2007.