Frequently asked questions about LLLT

Low level laser therapy is becoming more and more popular treatment method. There are many questions about efficacy, safety and medical studies of LLLT.

What kind of diseases could be treated with LLLT?

When we regard efficacy of LLLT in macro scale we find very important antyinflammatory impact. However all effects of LLLT have a source on cellular level. In practice low level laser therapy could be used for treatments of:

musculoskeletal disorders like muscle pains
arthritis
tendinitis
carpal tunnel syndrome
neck pain
back pain
wound therapies
sport injures of soft tissues

Is low level laser therapy scientifically well documented?

There are more than 130 double blinded medical studies confirming LLLT effectiveness. It has already been published more than 3000 research reports. Every year there are more than 250 new ones.A place where we can find many of them is PubMed.

One can hear that there are many studies reporting lack of efficacy of LLLT. What is the truth?

Each medical study should be considered separately. We have to realize that LLLT is not a panacea for all medical problems. If a scientist performs a medical study based on improper assumption, with improper laser doses it will not prove the efficiency of LLLT. There are some conditions necessary to fulfil to achieve desired positive results of a medical study:

Diagnosis should be correct
Therapy must affect disease agent
Proper treatment parameters and appropriate doses should be applied
Laser unit should have reliable parameters

Let’s be honest, if we administer improper medication we can’t expect any successful results.

Is it possible to replace acupuncture needles using laser probe?

While using laser probe we get similar results. Similar means not the same. The advantage is that it isn’t necessary to impair the skin. In some countries only doctors are allowed to make an acupuncture treatment.

What are the most important parameters in LLLT?

The most important parameter is dose. It is expressed in J/cm2. We can calculate number of Joules when we multiply laser output power by a time of exposure. For instance if we have 400mW laser probe and treatment lasts for 60 seconds we will receive:

400mW * 60 seconds = 24 000 mJ = 24 J

To calculate the proper dose we have to divide our energy in Joules by the area of treatment. For instance if we provide laser radiation to 12 cm2 we will receive:

24J / 12 cm2 = 2J/cm2

We must be aware that if we have modulation in laser radiation we must recalculate the power to get the average power. For instance if we have rectangle modulation of 50% duty cycle we will provide only 50% of peak power to the body.

Is it possible to damage eye by means of LLLT probe?

There are some circumstances which cause that one laser beam is more dangerous than the others. One of the risk factors in the case of laser therapy is the power density of a particular applicator. If even a relatively low power we will focus significantly, the radius received in that way will be dangerous. Currently used point probes emit divergent radiation. This is clearly seen at the red probe when we direct it on a wall – the further the wall is located, the larger area is illuminated. Even when we look directly at the probe from a distance the amount of energy that goes into our pupil is small.

When using a scanning applicator the reflection risk is much higher than in case of a manual probe or cluster laser applicator.

The other risk factor is the wavelength. Human vision has got perfect accommodation in case of visible light. In case of infrared light accommodation is much lower. That is why all sources of infrared light are more dangerous for the eye.

According to health and safety regulation using protective googles for therapist and patient is an obligation. Protective googles delivered in the set with laser unit give 100% protection.

How deep does the laser penetrate into the tissue?

The proper question should be – how deep is the laser radiation effective.

It depends on:

The wavelength of 630-660nm penetrates the tissue only over a few millimetres
The wavelength of 810nm can even reach up to 60mm
Adipose tissue is a good laser radiation transmitter
Muscle tissue is a poorer transmitter and the transmitting factor depends on the amount of blood in irradiated area.
Parallel beam seems to penetrate better but it scatters on tissue
When we make treatment in contact with the skin and we make some pressure on the skin we deprive the skin of the blood. Haemoglobin absorbs laser radiation very well so in the tissue without blood the penetration is better.
Penetration depth depends also on the skin colour.

Can LLLT cause cancer?

According to currently available medical studies, LLLT cannot cause cancer. When we treat cancer cells outside the human body we can stimulate them. Experiments on animals show that when we treat small tumours we can even heal them. When we stimulate big tumours, laser radiation has no effect. The explanation is that the body’s immune system response is stronger than the local stimulation of cancer cells.

Does laser radiation affect the bacteria and viruses?

The impact of LLLT is similar like in case of treating cancer tumours. Independent cultures of bacteria are growing by irradiation of laser light. Bacteria clusters in the body die due to increased immune response. There are even some reports about enhancing vaccine results when stimulating by laser radiation in point of puncture.

What happens when we overdose LLLT?

LLLT is efficient when we obey the indications of applying. When we exceed the dose significantly we can obtain even the biosuppressive effect. For instance a wound healed in this way may need longer time for recovery.

What are the contraindications for LLLT?

There are some common contraindications for all physiotherapy methods. One of them is cancer. But we know from medical studies that LLLT cannot cause cancer. This contraindication stems more from fear of being accused of causing patient harm than research. If LLLT had been so dangerous, the detailed cancer tests with current study tumour markers would be required before treatment.

There are also other contraindications such as pregnancy, diabetes, etc., however they remain a subject to the discretion of the physician. If the medical effects as in the case of diabetic foot therapy are significant, and the risk of disorders of insulin treatment is negligible, the treatment is considered to be well founded.