LLLT, lllt, laser therapy - biostimulation
The Low Level Laser Therapy -
LLLT Internet Guide

LLLT - laser therapy -
Guest Editorial


This page includes

Preoperative Low Level Laser application to reduce post-operative pain in patients receiving winograd type of partial matrixectomy surgery of hallux.
PHYSICAL MECHANISMS OF BIOLOGICAL EFFECT OF COHERENT AND NONCOHERENT LIGHT.
 
See other editorials

 

LaserWorld invites you to send a Guest editorial.

Clinicians, researchers and other persons in the world of LLLT are invited to send a contribution.
The subject is entirely up to the guest editor. It can be results from pilot studies, thoughts about dosages, nomenclature, suggestions for new research, interesting clinical observations, a glimpse of information about the direction of on-going research and so forth.

We feel there is a need for an interim forum for LLLT information. A good study can take a year to complete and another year or so of waiting before it is accepted for publication. Then, a quick look at the results could be valuable. And further, many qualified clinicians do not have the time, money or patience to make scientific studies.
But still they have a lot of expertice which they would be willing to share with others, should there be a suitable forum for it. And from the perspective of the therapist: Who can afford to subscribe to several scienticis magazines? So where can I find out about new research and new clinical observations without spending a fortune on subscriptions and congresses?

Well, this is precicely the "void" LaserWorld Guest Editorial wants to fill! Several persons have been invited to send their contribution. But we certainly accept unsolicited contributions, but reserve the right to edit them (in cooperation with the author) or to refuse publication.

email




Preoperative Low Level Laser application to reduce post-operative pain in patients receiving winograd type of partial matrixectomy surgery of hallux.

Les Jonsson B H Sc (Podiatry). Dip. Podiatry, Dip Podiatric Surgery, Dip. Soc. Sc. (Psychology). Cert. L.L.T. email ljohnson@contact.net.nz

Mary Needham, R.G.O.N., Cert., L.L.T.

Introduction

Low level laser was introduced as a part of our surgical regime to assist with post operative healing following digital surgery. It was observed that fewer patients returned for post-operative redressings complaining of post operative pain. A pilot study has been undertaken to report the level of pain experienced by patients who received a Winograd type partial matrixectomy of the hallux. To reduce the number of extraneous variables the surgery was undertaken in the same setting with the same surgeon and staff with the same operative instructions provided. Laser Therapy was used within 30minutes of surgery.

Methodology

Each patient was placed on the operating table in the supine position. The laser probe was placed against the epidermis and applied at 1.8J/cm 2 ,5.7Hz, with wavelength 830 nm and output power 40mW. from a "Maestro", laser manufactured by Medicom, Praha , Czech Republic . The probe was applied at 2 points at each surgical site and at one point at each of the two sites for undertaking the digital anaesthetic block at the proximal aspect of the great toe. A mixture 5cc of 50/50 2% plain xylocaine and 0.5% Marcaine was injected dorsal to plantar into the proximal aspect of the great toe. The feet were prepped and draped in the normal sterile manner. A partial nail plate avulsion was achieved with removing 2-3mm of the fibular and/or tibia nail borders. A Betadine scrub was then undertaken. This was followed with an incision proximal to the proximal end of the matrix along the course of the new nail edge to the distal end of the nail. A second incision was made in a semi elliptical fashion from the proximal end of the first incision along the course of the original nail border joining with the distal end of the first incision. Both incisions were made down to bone and all tissue was removed. Matrix within the cavity was removed. Saline irrigation was applied to the cavity. The cavity was closed with Proline sutures at proximal and distal ends with steristrips across the nail section. The tourniquet was released and blood flow was observed to return to the area. A dressing of Betadine and Bactagras was applied with 4 x 4 sterile gauze, followed by gauze bandage and Coban.

Each patient was given oral and written instruction and an appointment for redressing in 5 to 7 days. Instructions included the suggestion that the patient take Panadol. Each patient appeared tolerated the procedure well and left the surgery ambulated.

One returning to the surgery after five to seven days for redressings, each patient scored on a 10cm Visual Analogue Scale, the level that best illustrated the highest level of pain that they experienced following the operation.

Results

Those in the Laser group (N=12) scored an average of 2.1 whereas those in the Non laser group scored an average 7.2 (N=3).

Conclusion

The level of self medication for pain relief was not monitored and no breakdown of ethnicity, age or sex was recorded for any patients. The authors note the small number of subjects in this study, in particularly the “No Laser” group. Given the low pain scores of the laser group reporting low pain scores, it is expected that these authors will afford all future eligible patients the opportunity of pre-operative laser therapy for this and other types of surgery. Other practitioners who do not use laser, who use like surgical techniques are encouraged to conduct a similar study on their patients, to make a comparison with the current study and to report their findings.

 

 

PHYSICAL MECHANISMS OF BIOLOGICAL EFFECT OF COHERENT AND NONCOHERENT LIGHT.
A.N. Rubinov
Stepanov Institute of Physics
National Academy of Sciences of Belarus

Skorina Avenue 70, Minsk, Belarus,
e-mail:

   Extraordinary biological action of low intensity laser radiation is well known and widely used in laser therapy. In spite of a great success in this field the primary mechanism of laser stimulating effect remains disputable. The main question to be answered is: whether the observed effects are caused by absorption of light by some photoreceptors, the excitation of which starts some chains of biochemical events, or we encounter here with some other mechanism of interaction of light with biological matter. If the first is true, i.e. primary interaction of light with biological object is of pure photochemical nature, then we must find those receptors, study their properties and look for the light source, which emission is best overlapped with the absorption band of the receptors. In this case coherence and polarization of light can not be of importance.
   Indeed high coherence of light (i.e. when the phase of oscillations in electromagnetic wave remains unchanged for a long time) may be important if the phase of electron oscillations in a substance, excited by light, is also kept unchanged long enough. Large biomolecules contain tremendous number of atoms, interaction between which leads to very fast loss of the electron oscillations phase (during 10-13 sec or less). Because of this reason high coherence of light is not needed, and photochemical effects produced by coherent and noncoherent light will be indistinguishable.
   One may use a concept of spectral properties of light and substance instead of coherence and phase memory. Then the above statement can be expressed in the following form: as the spectral absorption bands of organic substances are quite broad (which means that the phase memory is short) one does not need for exciting a photochemical reaction the light with very narrow spectral line (coherent light).
   Polarization of light normally is also not important in photochemical process. It could be important if all (or majority of) absorbing molecules were oriented in space such a way that their transition moments happened to be aligned along some preferential direction. But there is absolutely no reason why the mentioned above hypothetical photoreceptors would be aligned in a body along one direction. And for random orientation of photoreceptors in a body the polarized and nonpolarized light will produce the same effect.
   So we may conclude that if the biological effect of light is based on photochemical processes (i.e. on resonance interaction of light with absorbing molecules) the coherence and polarization of light do not play any important role. From this point of view there is no special reason for using lasers in therapy instead of photodiodes or other noncoherent light sources. In case of noncoherent light source there is also no sense in using polarized light.
   However there are enough of data today indicating importance of coherence (superior qualities of lasers) and polarization at application of light in therapy [1]. From this follows that there must exist some nonresonant mechanisms of light interaction with biological matter, which determine universal action of laser light on a human body. Of course, one can not deny existence of specific photochemical interactions of light with some substances in a body (superoxideolis-mutase, catalase, ceruloplasmin, cytochromes a and a3, cytochromoxidase, endogenic porphyrins, oxygen). But those specific interactions can hardly explain universal stimulating biological effect of laser light observed for very wide range of laser wavelengths.
   In case of nonabsorbing medium the photochemical mechanisms are excluded. Nevertheless light may influence the properties of such transparent medium. In case of inhomogeneous medium like a biological one the considerable effect might be caused even at low intensities of light. Nonresonant action of light on transparent dielectric objects (for example cells) is based on the interaction of light induced dipole moments of these objects between themselves or with the incident light field. Two cases must be distinguished: interaction with noncoherent and coherent light.


   I. Noncoherent light (importance of polarization). Illumination of particles (cells) with light induces in them oscillations of electrons which are synchronous for all particles. This effect takes place for both laser and non-laser sources (lamps, photodiodes). If particles are packed closely enough to each other (as cells in a body) the dipole moments induced in them interact as is shown in the Fig. 1. As dipole moments in all particles oscillate synchronously their polarities are kept identical in respect to each other all time. The result of interaction strongly depends on light polarization. Both attraction (Fig. 1a) and repulsion of particles to each other (Fig. 1b) can be realized depending on orientation of electrical vector of electromagnetic wave relatively the pair of interacting particles. For linearly polarized light the orientation of electric field oscillations remains constant which provides preservation of the type of interaction in time (attraction for the case of Fig.1a and repulsion in the case of Fig.1b). For circularly polarized light or nonpolarized light orientation of electrical oscillations in respect to the particles position changes very fast (from the case of Fig 1a to the case of Fig1b and back). As a result repulsion and attraction replace each other very quickly and on the average the force of interaction between particles becomes equal to zero.

   So we may make the first conclusion: noncoherent light may influence ensemble of particles (biological system) through light induced dipole-dipole interaction.
The effect is realized only for linearly polarized light and is absent if the incident light is circularly polarized or nonpolarized.

   There is another possibility of nonresonant action of light on particles – optical Kerr effect. If polarizability of a particle is anisotropic then the direction of a dipole moment induced by light in the particle may not coincide with the direction of electrical vector of light (as is shown in the Fig.2a). Due to that a torque appears which causes rotation of a particle until its dipole moment becomes aligned along the electrical vector of the field (Fig.2b). Linear polarization of the incident light is also necessary to produce this effect.

   In comparison with the dipole-dipole interaction the optical Kerr effect is less probable at interaction of low intensity light with biological objects. Because of low intensity of light, required by biological safety, considerable torque may appear only for particles of micron scale size. Such large particles contain large number of electrons whose oscillations are summarized producing the light induced dipole moment of the whole particle. If the particle is not a crystal but a biological cell or an organelle then it is difficult to expect essential anisotropy over the whole volume of a particle.
   So the second conclusion is that in principle noncoherent light may also act on particles via optical Kerr effect causing some torque acting on them. The effect also requires linearly polarized light. But this mechanism of light action on biological system is less probable in comparison with dipole-dipole interaction.

   Coherent light.
   Both above mechanisms may also act in case of coherent light. But in addition to that there is a specific physical mechanism which distinguishes action of laser light on a biological system from the action of noncoherent one.
   The specific feature of illumination of an object with coherent light is formation of the so called speckle structure. This is a strong micron-scale modulation of light intensity, which unavoidably appears at the surface and in a bulk of optically inhomogeneous medium even at ideally uniform illumination. Such modulation is a result of the interference of micro-beams reflected and scattered by heterogeneous medium (Fig.3).

 

It is formed only at illumination of an object with coherent light. The higher degree of the coherence the higher degree of the intensity modulation in a speckle structure is observed. At illumination of the same object with noncoherent light from lamps, photodiodes or so like the speckle structure disappears and the object appears illuminated uniformly.
   Interaction of the speckled light field with particles leads to appearance of so called gradient forces. The gradient forces have electric nature and can be easily understood with help of the Fig. 4.


   Let us assume that some dielectric particle is placed in the homogeneous electric field. Under the action of the field the particle becomes polarized and two Coulomb forces acts on separated charges in opposite directions. If the field is homogeneous the two forces compensate each other, and the resulting force acting on the particle is equal to zero (Fig. 4a). But if the electric field is non-uniform and has a gradient along some direction then Coulomb forces, acting on the particle in the opposite directions, do not compensate each other any more. In this case the resulting force (which is called gradient force) is not equal to zero, and drives the particle towards the stronger field (see Fig. 4b). This is also true for alternative electric component of electromagnetic wave. The electrons in the particle follow synchronously oscillations of electric component of the electromagnetic wave. This is why the resulting force does not change its direction, in spite of oscillations of electric field in a light wave, and always points towards the region of the higher field strength (compare of Figs. 4b and 4c).
   From above considerations follows that if a light field with modulation of intensity in space (gradient field) is applied to particles, they will be subjected to action of gradient forces pulling them to the region of maximal intensity. Such forces are well known in optics and employed in laser tweezers.
   Calculations show that at application of low intensity lasers to a medium at room temperature the gradient forces are quite important for comparatively large particles whose sizes are of a micron scale. For small particles like molecules the energy of interaction connected with gradient forces is much smaller than the thermal energy of molecules at room temperature, and the action of those forces can be ignored.
   Now we can make another important conclusion: there is a specific influence of coherent light on a system of particles (cells in a biological system) which is based on the action of gradient forces originated by speckle structure of laser field inside the illuminated object. Polarization of light is also a factor of importance for this mechanism of action: effect of gradient forces is stronger for linearly polarized light because in this case the speckle structure of laser field has a higher contrast.
   Theoretical estimation shows that at typical conditions of illumination of a body with low intensity lasers the gradient forces plays major role in comparison with the dipole-dipole interactions.
So finally the above considerations lead us to the following conclusions:

  1. Apart from a photochemical mechanism of light action on biological systems there exist more universal physical mechanisms based on interactions of light induced dipole moments of particles between themselves and with electrical component of light field. Both laser and non-laser light can produce biological effect via these mechanisms.
  2. Laser light is the most efficient at action on biological systems. At that linearly polarized laser light is expected to produce better effect than nonpolarized or circularly polarized one.
  3. Non-laser light can also produce biological action but of smaller efficiency than the laser one and only in case if it is linearly polarized.


   The action of gradient laser fields on particle ensembles and biological systems was considered in [2]. In particular it was shown that action of gradient laser fields on micron scale particles (cells, organelles large biomolecules) may influence biological processes through the following processes:

  • change of local concentration and spatial orientation of particles;
  • change of composition of particles of different type;
  • selective increase of the partial temperature for larger particles;
  • small reversible distortions of particles structure (cellular massage);
  • stimulation of conformational changes in enzymes and other
    structures.

 


 

Fig. 5 illustrates action of gradient forces on 6 ? plastic particles in water illuminated by the interference field of He-Ne laser. One can see that under the action of gradient laser field all particles are gathered at the maximums of laser intensity. So the laser field here causes change of local concentration of particles.


Fig. 6 shows effect of spatial orientation of particles by a gradient field of Ar-laser. Two erythrocytes which at the first moment happened to be oriented by their long sides across the interference fringes (created by interference of two laser beams) some minutes later became oriented along the fringes.


Fig. 7 demonstrates splitting of erythrocyte rouleau by the interference field of Ar-laser. Uniform illumination of an erythrocyte rouleau with a single beam of the laser does not cause any change in its structure. But as soon as the interference structure is created (by switching on the second laser beam) the rouleau is immediately split into separate red blood cells.
There are also other experiments described in [2] which prove essential influence of gradient laser fields on some fundamental processes in a cell.

References
1. J Tunér and L Hode, "Laser Therapy. Clinical; practice and scientific background", Prima Books AB, 2002
2. A.N. Rubinov, J. Phys D: Appl. Phys. 36 (2003) 2317-2330.

Captions to figures

Fig.1. Interaction of dipole moments induced by light in neighboring particles.
a) – particles attract each other when electrical vector of light E is parallel to the line connecting the particles; b) - particles repel each other when electrical vector of light E is perpendicular to the line connecting the particles;

Fig.2. Rotation of the particle characterized by anisotropic polarizability under action of linearly polarized light. a) – the torque acts on a particle because the light induced dipole moment P does not coincide with the direction of the electrical vector E of the light field. b) – particle is aligned with its dipole moment P along the electrical vector E under action of the torque.

Fig.3. Interaction of reflected and scattered micro-beams in an inhomogeneous medium, which causes appearance of speckles of a laser field in the medium.

Fig.4. Polarization of a dielectric particle under action of uniform (a) and not uniform (b, c) electric field; b) and c) show that at change of the electric field sign the direction of the gradient force does not change.

Fig.5. Trapping of 6 ? plastic particles in water under action of gradient forces in the interference field of a He-Ne laser; a) – random distribution of particles at illumination by a single laser beam. b) – distribution of the particles in the fringes of the two beam interference laser field.

Fig.6. Aligning of erythrocytes under action of gradient forces in the interference fringes of Ar laser; a) – the first moment after the interference field has been switched on; b) – several minutes later – both erythrocytes have oriented themselves along the interference fringes.

Fig.7. Splitting of the erythrocyte rouleau under the action of gradient forces of the Ar-laser interference field; a) an erythrocyte rouleau illuminated by a single laser beam; b) – splitting of the rouleau into separate erythrocytes at switching on the interference field.

 
 
 



 
Other Editorials - Quick-jump
Latest Editorials
 
 

Preoperative Low Level Laser application to reduce post-operative pain in patients receiving winograd type of partial matrixectomy surgery of hallux.

PHYSICAL MECHANISMS OF BIOLOGICAL EFFECT OF COHERENT AND NONCOHERENT LIGHT.

A Trial of Low Level Laser Therapy for Reduction of Tinnitus Symptoms

ROLE OF ACULASER THERAPY IN CEREBRAL PALSY CHILDREN. (INITIAL DATA & RESULTS)

Class IV Laser in Non-invasive Laser Therapy

Laser therapy of human herpes simplex lesions

CLINICAL EFFECTS OF FOCALISED AND DEFOCALISED CO2 LASER ON EQUINE DISEASES

Bone Stimulation by Low Level Laser - A Theoretical Model for the Effects LASER

ACUPUNCTURE FOR INDIAN NATIONAL WOMENS GOLF

 
 
 
 
 
 
  Laser light - a new, non invasive treatment for Erectile Dysfunction: a placebo-controlled, single blinded pilot study
  Antipodean perspectives of the World Association for Laser therapy (WALT) Conference, June 27-30, Tokyo, Japan.
Summary of the significant articles from WALT 2002.

ABOUT TIME TO GET TO SPEAK THE SAME LANGUAGE
  Low Level Laser Therapy of Sinusitis

Combining nanotechnology with LLLT: visions for the next 10 years
 

Low Level Laser Therapy in Children’s Allergic Purpura
by C. Ailioaie, Laura Ailioaie, Iassy, Romania

A LITERATURE REVIEW OF POSSIBLE EFFECTIVE INTERVALS OF RED AND INFRARED LASER IRRADIATION FOR ENHANCED TISSUE REPAIR IN THE HUMAN LOCOMOTOR SYSTEM
By Bjordal- Jan M.*, Couppe-Christian, Ljunggren-Elisabeth A.

Laser therapy in coronary medicine - a brief look at the literature
By Jan Tunér DDS

 

8th International Congress of the European Medical Laser Association in Moscow
Miroslav Prochazka, Member of EMLA Parliament, Prague, CZ, Premysl Fryda, Member of EMLA Parliament, Prague, CZ No:  17-19

Biostimulatory Windows in Low Intensity Laser Activation:
Lasers, Scanners and NASA's Light Emitting Diode Array System
By Dr. Andrei P. Sommer.

The Cochrane analyses - can they be improved?
Jan Tunér DDS

 

The mangement of diabetic neuropathic ulceration by HeNe laser.
The following photo sequence has been contributed
By Dr. Ali Abaci, Turkey

Laser irradiation of the blood
By Levon Gasparyan, MD, PhD

Laser Treatment for Tendinitis
By Jan M. Bjordal, PT-MSc,


LOW INTENSITY LASER THERAPY TO TREAT DENTIN HYPERSENSITIVITY - COMPARATIVE CLINICAL STUDY USING DIFFERENT LIGHT DOSES
By Rosane de Fátima Zanirato Lizarellia ; Marcelo de Oliveira Mazzettob ; Vanderlei Salvador Bagnatoa

LLLT and the healthy rat model for wound healing research -
is it a feasible idea?
Interview with Dr. Farouk Al-Watban

  Low level laser therapy (LLLT) - Does it damage DNA?
By K.O.Greulich


Laser and Plaquex treatment on cryoglobolic vasculitis on diabetic foot
(Case report summary)
By Anita Baxas


The Roles of Laser Therapy in tissue Repair and Sports Injuries
By Chukuka S. Enwemeka, P.T., Ph.D.,


Regulation of Medical Devices in Australia
By Peter A. Jenkins MBA

  Low-level laser therapy after molar extraction
Hana Kucerováa, Tatjana Dostálováa, Lucie Himmlováa, Jirina Bártováa, Jirí Mazánekb
  100 positive double blind studies - enough or too little?
By Jan Tunér DDS
Lars Hode, Dr Sci

Treatment of Chronic Rheumatoid Arthritis
by Low Power Laser(1)
By Kazuyoshi Zenba,,

Lymphoedema and Laser Therapy
By Ann Thelander

LOW LEVEL LASER THERAPY IN DENTISTRY - PREVENTIVE PERFORMANCE.
By Dr. Rosane Lizarelli, DDS
  Chemo-induced mucositis. Results of multicenter phase III studies.
By René-Jean Bensadoun,

LaserWorld Guest Editorial, Tiina I.Karu - April 1999.
HOW TO FILL UP A GAP?

Treatment of Atopic Dermatitis by Low Power Laser
Takao Igarashi, MD

This page was last updated on :

email

1998-2001 copyright © Swedish Laser-Medical Society -All rights reserved

 

webmaster