Laser and Polarized Light

Photomed Laser Surg.  2010 Aug;28(4):489-96.

Healing of surgical wounds made with lambda970-nm diode laser associated or not with laser phototherapy (lambda655 nm) or polarized light (lambda400-2000 nm).

Medeiros JL, Nicolau RA, Nicola EM, dos Santos JN, Pinheiro AL.

Center of Biophotonics, School of Dentistry, Federal University of Bahia, Salvador, Bahia, Brazil.


OBJECTIVE: The aim of this study was to analyze the effect of two phototherapies, laser and polarized light, on diode laser (970lambda nm) wounds.

BACKGROUND DATA: Lasers have been used in surgery, and some wavelengths may cause thermal damage to the tissue and affect healing. Several studies have shown that some wavelengths are effective in improving healing. Coherent and noncoherent light have been successfully used on the modulation of biological phenomena of several origins.

ANIMALS AND METHODS: Thirty-one Wistar rats were divided into 3 groups (GI to GIII). A 20-mm x 2-mm wound was created on the dorsum of each animal with a diode laser (Sirolaser, Sirona, Bensheim, Germany). Group GI acted as control. On GII, laser light (lambda655 nm, 30 mW, phi approximately 3 mm, 12 J/cm(2)) was used and on GIII illumination with polarized light (lambda400-2000 nm, 40 mW, phi approximately 5.5 cm, 12 J/cm(2)) was used, every other day (GII) or daily (GIII) for 7 days. The animals were killed at 0, 7, and 14 days after surgery. Specimens were taken, routinely processed, stained and imunnomarked [HE (hematoxylin-eosin), sirius red, alpha-smooth muscle actin (SMA)], and underwent histological analysis.

RESULTS: GII showed better response at day 14 when re-epithelialization was in a more advanced stage. The number of myofibroblasts was significantly different over the healing time (7 to 14 days); this number was smaller than that observed on G1. On GIII at day 7, the number of myofibroblasts was significantly higher than for GII. At day 14, a more pronounced deposition of collagen matrix was also seen, and inflammation was discrete and more advanced for GIII.

CONCLUSION: The results of the present study showed that the effect of the use of laser light was more evident at early stages of healing and that the use of polarized light improved the resolution of the inflammatory reaction, increased the deposition of collagen, increased the number of myofibroblasts, and quickened re-epithelialization during the experimental time.

Photomed Laser Surg. 2009 Jun;27(3):513-20.

Comparing the effects of exercise program and low-level laser therapy with exercise program and polarized polychromatic non-coherent light (bioptron light) on the treatment of lateral elbow tendinopathy.

Stasinopoulos D, Stasinopoulos I, Pantelis M, Stasinopoulou K.

Rheumatology and Rehabilitation Centre, Athens, Greece.


BACKGROUND DATA: The use of low-level laser therapy (LLLT) and polarized polychromatic non-coherent light as supplements to an exercise program has been recommended for the management of lateral elbow tendinopathy (LET). OBJECTIVE: To investigate whether an exercise program supplemented with LLLT is more successful than an exercise program supplemented with polarized polychromatic non-coherent light in treating LET. MATERIALS AND METHODS: Patients with unilateral LET for at least 4 wk were sequentially allocated to receive either an exercise program with LLLT or an exercise program with polarized polychromatic non-coherent light. The exercise program consisted of eccentric and static stretching exercises of wrist extensors. In the LLLT group a 904-nm Ga-As laser was used in continuous mode, and the power density was 130 mW/cm(2), and the dose was 0.585 J/point. In the group receiving polarized polychromatic non-coherent light the Bioptron 2 was used to administer the dose perpendicularly to the lateral epicondyle at three points at an operating distance of 5-10 cm for 6 min at each position. The outcome measures were pain and function and were evaluated at baseline, at the end of the treatment (week 4), and 3 mo after the end of treatment (week 16). RESULTS: Fifty patients met the inclusion criteria. At the end of treatment there was a decline in pain and a rise in function in both groups compared with baseline (p < 0.0005 on the paired t-test). There were no significant differences in the reduction of pain and the improvement of function between the groups at the end of treatment and at the 3-mo follow-up (p > 0.0005 on the independent t-test). CONCLUSIONS: The results suggest that the combination of an exercise program with LLLT or polarized polychromatic non-coherent light is an adequate treatment for patients with LET. Further research to establish the relative and absolute effectiveness of such a treatment approach is needed.

Masui. 2009 Nov;58(11):1401-6.

Phototherapy for chronic pain treatment

[Article in Japanese]

Ide Y.

Department of Anesthesia, Toho University Sakura Medical Center Sakura 285-8741.


Three types of machines are used in the field of phototherapy for chronic pain. One type is an instrument for low reactive level laser therapy (LLLT), one is an instrument for linear polarized infrared light irradiation (SUPER LIZER), and the last one is an instrument for Xenon light irradiation (beta EXCEL Xe10). The available machines for LLLT all project laser by semiconductor. The newest machine (MEDILASER SOFT PULSE10) has peak power of 10 W and mean power of 1 W. This machine is as safe as 1 W machine and is effective twice as deep as the 1 W machine. The irradiation by low reactive level laser induces hyperpolarization, decreased resistance of neuronal membrane, and increased intra-cellular ATP concentrations. The effects of low reactive level laser might be induced by the activation of ATP-dependent K channel. The significant analgesic effects of 1 W and 10 W LLLT were reported with double blind test. The significant analgesic effects of linear polarized near infrared light irradiation with double blind test were also reported. The effects of low reactive level laser upon the sympathetic nerve system were thought to result from its normalization of the overloaded sympathetic nerve system.

Masui. 2006 Sep;55(9):1104-11.

[Equipment for low reactive level laser therapy including that for light therapy]

[Article in Japanese]

Saeki S.

Department of Anesthesiology, Nihon University School of Medicine (Surugadai Nihon University Hospital), Tokyo.

Equipments used for light therapy include machinery used for irradiation by low reactive level laser, xenon light and linear polarized infra-red ray. Low reactive level laser is divided into two types of laser according to the medium by which laser is obtained ; semiconductor laser and helium-neon laser. Low reactive level laser has only one wave length and produces analgesia by action of light itself. On the other hands, Xenon light and linear polarized infra-red ray produce analgesia by warming effect induced by light in addition to the action of light itself. There are four methods of irradiation by these light sources; irradiation of acupuncture points, of trigger points, along nerves causing pain and of stellate ganglion area. Indication for light therapy includes various kinds of diseases such as herpes zoster, post herpetic neuralgia, cervical pain, lumbago due to muscle contracture, complex regional pain syndrome, arthralgia etc. However, we have to know that light therapy does not exert analgesic effects equally to all patients. But light therapy does not accompany pain and rarely shows any side effects. Therefore it is thought to be an alternative for patients who reject injection or patients who are not indicated for nerve block because of patients’ conditions such as bleeding tendency.

Photomed Laser Surg. 2005 Oct;23(5):485-92.

Polarized light (400-2000 nm) and non-ablative laser (685 nm): a description of the wound healing process using immunohistochemical analysis.

Pinheiro AL, Pozza DH, Oliveira MG, Weissmann R, Ramalho LM.

Laser Center, School of Dentistry, Federal University of Bahia (UFBA), Bahia, Brazil.


OBJECTIVE: This study aimed to describe, through morphologic and cytochemical analysis, the healing process of wounds submitted (or not) to laser therapy (lambda685 nm) or polarized light (lambda400-2000 nm). BACKGROUND DATA: There are many reports on different effects of several types of phototherapies on the treatment of distinct conditions, amongst them, on wound healing. Laser therapy and the use of polarized light are still controversial despite successive reports on their positive effects on several biological processes. METHODS: Thirty male Wistar rats, approximately 4 months old, were used, and standardized excisional wounds were created on their dorsum. The wounds were irradiated in four equidistant points with laser light or illuminated with polarized light, both with doses of 20 or 40 J/cm2. Group 1 acted as untreated controls. Animals were irradiated every 48 h during 7 days, starting immediately after surgery, and were humanely killed on the 8th post-operative day. Specimens were taken and routinely processed and stained with H&E, and for descriptive analysis of myofibroblasts and collagen fibers, the specimens were imunnomarked by smooth muscle alpha-actin and picrosirius stain. RESULTS: Control specimens showed the presence of ulceration, hyperemia, discrete edema, intense, and diffuse inflammation, collagen deposition was irregular, and myofibroblasts were seen parallel to the wound margins. Wounds treated by laser therapy with a dose of 20 J/cm2 showed mild hyperemia, inflammation varied from moderate to intense, the number of fibroblasts was large, and the distribution of collagen fibers was more regular. Increasing the dose to 40 J/cm2 evidenced exuberant neovascularization, severe hyperemia, moderate to severe inflammation, large collagen deposition, and fewer myofibroblasts. On subjects illuminated with polarized light with a dose of 20 J/cm2, mild to moderate hyperemia was detectable, and collagen matrix was expressive and unevenly distributed; a larger number of myofibroblasts was present and no re-epithelialization was seen. Increasing the dose resulted in mild to moderate hyperemia, no re-epithelialization was seen, edema was discrete, and inflammation was moderate. CONCLUSION: The use of 685-nm laser light or polarized light with a dose of 20 J/cm2 resulted in increased collagen deposition and better organization on healing wounds, and the number of myofibroblast was increased when polarized light is used.

Used by the kind permission of Laser Partner,

Six Years´ Experience with Therapeutic Effects of Polarized Light in Comparison with Biostimulation Laser

Marta Routnerova, M. D.

Center for Connected Rehabilitation, Prague, CZ

We have been utilizing therapeutic effects of polarized light in treating outpatients in our Center for six years. In general we perform this method of treatment 3 to 4 times per week, in sporadic cases even every day, mostly 10 to 15 applications in succession. In the course of past six years we have carried out total of 8716 therapies with polarized light. Within this figure, in 2/3 of applications we have been using stand-mounted polarization lamp BIXUN, whilst remaining 1/3 of therapies, especially where exactly directed applications were required (in the face, in the scalp, at the insertion of neck muscles), have been carried out with hand-held Biolamp operated by therapist, or by properly instructed patient himself/herself.

The range of applications for children as well as for adults stems from characteristic features of polarized organization of emitted light with the ability of penetration in deep tissue structures, with specific impact on molecular structure of cellular membrane, with strengthening effect on cellular metabolism and thus on acceleration of regenerative ability and healing processes, on suppression of inflammatory processes and analgetic effect.

Depth of penetration into tissue is reported up to 5 and more centimeters. Penetration increases the temperature locally, however photochemical changes caused by polarized light itself are much more important, for these bring said analgetic, anti-inflammatory, and biostimulative effects. Analgetic effect is a result of changes in potential of cellular membranes of neural cells, bringing increased limen of irritation, increased creation of beta-endorphines as well as opioides. Anti-inflammatory effect is caused by decreased formation of prostaglandines in tissue affected by inflammatory processes. Biostimulative effect is generated by influence of polarized light on molecular structure of cellular membranes and on mitochondrial apparatus, by acceleration of metabolic processes, and by stimulation of necessary control procedures in tissue. Significant effect is subject to stimulation of activity of macrofages necessary for healing of wounds, as well as stimulation of activity of fibroblasts which form a sound basis for healing of skin grafts and successfull scarring.

In the course of the above period we have carried out:

820   treatments of dermatologic ailments on body and extremities (eczemas, hypertrophic keloid scars
652   treatments in face and crinite part of head (cicatrix cheiloideus)
256   applications on herpes labialis
62   applications on dental complications after extractions (persisting oedemas, slow healing of the
post extraction wound)
1258   applications on neck – accute cervicalgia
1836   applications on area of central thoracic vertebra and on accute blocks in the area of sternocostal
1352   applications on low back pain
418   applications on pain syndromes in the area of arm girdle, including the frozen shoulder syndrome
601   applications on tennis and golf elbow
323   applications on small hand joints
326   applications on gonarthrosis
812   applications on sacroilialgias

Efficacy of treatments:

Dermatologic ailments (eczema, dermatitis)
– 65 % without other local treatments
– 72 % with simultaneous local dermatologic treatment

– 60 % old hyperthrophic keloid scars
– 82 % fresh hyperthrophic scars

Dental applications on persistent post extraction oedemas
– 52 % without parallel treatment with antibiotics
– 83 % with antibiotics

Slow healing of post extraction wounds
– 92 % efficacy

Lower back pain, thoracalgias, cervicalgias
– 54 % without parallel medication and rehabilitative physiotherapy, manual manipulation
– 97 % when treatment combined with non-steroid antirheumatics and analgetics,
reflex massages, soft mobilization techniques, possibly manipulations of vertebra

Frozen shoulder syndrome
– 62 % with only abduction positioning
– 82 % when treatment combined with physiotherapy, and analgetics and non- steroid antirheumatics medication

– 93 % without the necessity of supplementary medication, or of other physiotherapy procedures

Arthrosis and arthralgias
– 52 % without supplementary medication and/or local intraarticular injections
– 95 % with parallel medication with analgetics and non-steroid antirheumatics, possibly with
intraarticular applications of corticoids or other preparations, as well as with additional
physiotherapy in order to keep the range of mobility in joints.

Our Center for Connected Rehabilitation commands ten years of experience in laser therapy, which we have been utilizing He-Ne laser, laser scanner, and semiconductor diode hand-held laser probes with various wavelengths and outputs for. Thus we can compare advantages and/or disadvantages of therapies with the use of both laser and polarized light.

The main benefit of laser is bringing more emphatic therapy effect and quicker alleviation of pain. On the other hand, polarized light can be esteemed for simpler operation and no need for keeping to specific security and hygienic regulations, pertaining to laser, especially wearing special protective glasses is not required. However, somewhat lower effect of polarized light is compensated by lower purchase costs and by absence of expenses of necessary adaptation of a laser treatment cabinet.

Wavelength of the light in the range of 500 – 2000 nm meets all conditions for successfull utilization of polarized biolamps for above mentioned therapies. Introduction of frequency modulation of polarized light, based on the same principles as in laser therapy, can increase therapeutic effect of these devices, and shorten the time necessary for patients` healing and recovery. Our experience can well lead to a conclusion that polarized light and biostimulation laser have in many cases similar use, and to a certain extent even comparable results. Within one clinic both these methods can complement each other very well.

Prague, 20th February, 2000