Here is the complete information on laser therapy and the role of laser in physiotherapy.

1. Laser
Therapy
PREPARED BY: SAIMA MUSTAFA

2. Prepared by: Saima Mustafa

3. Laser Therapy
 Light Amplification by the Stimulated Emission of Radiation
 Compressed light of a wavelength from the cold, red part of the spectrum of electromagnetic
radiation .
 Monochromatic - single wavelength, single color .
 Coherent - travels in straight line .Polarized - concentrates its beam in a defined location/spot

4. Electro
magnetic
spectrum

5. History
Albert Einstein – 1 st described this theory that was transformed into laser therapy
By the end of the 60’s, Endre Mester (Hungary) - was reporting on wound healing through laser
therapy
In early 1960’s, the 1st low level laser was developed.
In Feb. 2002, the MicroLight 830 (ML830) received FDA approval for Carpal Tunnel Syndrome
Treatment (research treatment)
Laser therapy – has been studied in Europe for past 25-30 years; US 15-20

6. Class Levels 1-4
1 = incapable of producing damaging radiation levels (laser printers & CD players)
2 = low-power visible lasers (400-700 nm wavelength, 1 mW)
3 = medium-power lasers - needs eye protection
3a – up to 5 mW
3b** – 5 mw-500 mW
4 = high-power lasers– presents fire hazard (exceeds 500 mW)
Types of Lasers:
High
• Surgical Lasers
• Hard Lasers
• Thermal
• Energy – 3000-10000 mW

7. Low
• Medical Lasers
• Soft Lasers
• Sub thermal
• Energy – 1-500 mW
• Therapeutic (Cold) lasers produce maximum output of 90 mW or less
• 600-1000 nm light
• Four categories of lasers
• Crystal & Glass (solid - rod)
• Synthetic ruby & others (synthetic ensures purity)
• Semiconductor (diode - channel)
• Gallium Arsenide (GaAs under investigation) Liquid (Dye) - Organic dyes as lasing medium
• Chemical – extremely high powered, frequently used for military purposes

8. Laser Generators
Components of a generator:
• Power supply – electrical power supply that can deliver up to 10,000 volts & 100’s amps
• Lasing medium – gas, solid, liquid
• Pumping device – high voltage, photoflash lamps, radio-frequency oscillators or other lasers (pumping is
used to describe the process of elevating an orbiting electron to a higher, excited energy level)
• Optical resonant cavity – contains lasing medium.
• Low level laser therapy :
• Laser Therapy Acronym is Light Amplification by Stimulated Emission of Radiation Therapy.
• Low-level laser therapy (LLLT) is a pain-free, non-invasive, affordable tool used by physical therapists
throughout the healing process that is becoming more prevalent in PT practices nationwide .
• Laser Therapy works on the principle of inducing a biological response through energy transfer, in that the
photonic energy delivered in to the tissue by the laser modulate the biological processes within the tissue. So
it is called PHOTOBIOMODULATION.

9. Low level laser therapy continue……
• The photobiomodulation can have both: a) Photobiostimulative effect b) Photobioinhibitive effect
• The Laser Therapy effectiveness based on the principle of ‖The ArndtSchultz law‖ of biomodulation.
• The Arndt-Schultz law of Biomodulation infers that low dosage of photonic energy will stimulate the biological
process in the tissue the higher dosage of photonic energy will inhibit the biological process in the tissue.
• Laser Generators
• Lasers require the following components to be operational.
1. Power supply
2. Lasing medium (material)
3. Pumping device
4. Optical resonant cavity

11. Properties of laser
 Monochromaticity: Laser light is concentrated in a narrow range of wavelength (same
wavelength and same color).
 Coherence: All photons emitted in one phase (same time and distance).
 Collimation ( directionality): In one direction and non-spread (Focusing the beam of light
on certain point)
Classification of laser
1. According to nature of the material placed between two reflecting surfaces.
2. According to intensity.
3. According to hazards.

12. According to nature of the material placed between two reflecting surfaces.
1. Crystal lasers (solid state lasers) include - Ruby crystal (aluminum oxide and chromium) -
Neodymium crystal
2. Gas lasers include - Helium neon (HeNe) - Argon - Carbon dioxide (CO2)
3. Liquid laser - Polyphenyle – Oxazine
4. Chemical laser - Laser with high intensity not used therapeutically but used in industrial
production

13. According to intensity
a) High power: known as "hot" lasers because of the thermal responses they generate. These are used in
the medical realms in numerous areas, including surgical cutting and coagulation, ophthalmologic,
dermatologic, oncologic, and vascular specialties.
b) Low power: known as "low power laser therapy" or "low level laser therapy". It used for wound healing
and pain management. These lasers produce a maximal output of less than 1 milliwatt (1 mW = 1/1000 W)
causing photochemical, rather than thermal effects. No tissue warming occurs.

14. According to hazards
Class 1 (less than 0.5 mW)
• Visible and non-visible
• No eye or skin danger
• Laser printers, car entry, CD players
• No heating/no healing
• Safe in all uses unless focused through magnifier
Class 2 (less than 1 mW)
• Visible
• Safe for short periods on eyes and extended on skin
• Safe because blink reflex limits retina exposure
• No healing/no heating.
•

15. Class 3 (1mW to 500 mW)
• Visible and invisible.
• Helium neon (HeNe).
• Protective eye ware if direct viewing of beam.
a)Class 4 (more than 500 mW)
• Increases tissue temperature--can burn
• Dehydrates tissue
• Eye danger can result from indirect or reflected beam

16. Most Commonly Used Lasers :
I. Helium neon (HeNe)
II. Gallium arsenide (GaAs)

17. Physiological effects
 Reducing Pain
A. There is an increase in serotonin (5-HT) levels (inhibit pain transmission to brain and from nociceptors).
B. There are also increases in Beta Endorphins, which decrease pain sensation.
C. Decrease bradykinins (is an inflammatory mediator. It is a peptide that causes blood vessels to dilate (enlarge)) which can
be prevalent in injured tissue, induce pain sensation by stimulating nociceptive afferents.
D. Increase release of Acetylcholine: Acetylcholine helps normalize nerve signal transmission in the autonomic and somatic
pathways.

18.  Reducing Inflammation
A. Enhancement of ATP by stimulation of mitochondria.
B. Stabilization of the Cellular Membrane.
C. Acceleration of Leukocytic Activity

19.  Promoting Tissue Healing
A. Increased macrophage activity.
B. b) Increased fibroblast proliferation.
C. c) Keratinocyte proliferation. (Keratinocyte: the outermost layer of the skin The primary
function of keratinocytes is the formation of a barrier against environmental damage by
pathogenic bacteria, fungi, parasites, and viruses, heat, UV radiation)

20.  Recovery from nerve injury
a) Accelerate nerve regeneration ( by stimulation of Nerve growth factor)
b) b)Increase frequency of action potential.
c) c) Increase rate of nerve conduction.
 Increase bone and cartilage formation ( by stimulation of bone morphogenetic proteins that stimulate bone cell
differentiation)

21. Indications of laser therapy
I. Dermatological disorders : Wounds , Ulcers
II. Pain and inflammation in orthopedic and sport cases:
III. Ankle sprain, Chronic Low back pain, Tennis Elbow, Plantar fasciitis, Frozen shoulder
IV. 3. Neurogenic pain
V. Trigeminal neuralgia
Treatment procedures
I. Preparation of the patient:
II. The skin in the area of electrode placement should be cleaned by saline water, soap or Vaseline to lower skin resistance.
III. Special gels, sprays or water is applied to the skin as a condition medium for better stimulation. • c) Electrodes should be
fixed in position, using mending tapes to maintain good contact throughout the treatment period

22. Clinical application of laser
1. Calculation of laser dose.
2. Penetration of laser.
3. Techniques of laser
Calculation of laser dose dependent on:
(1) The output power of the laser in mw.
(2) The time of exposure in seconds.
(3) The beam surface area of the laser in cm2

23. Depth of Penetration
a)HeNe laser energy Absorbed rapidly in the superficial structures, especially within the first 2-5 mm of soft
tissue. The response that occurs from absorption is termed the "direct effect." HeNe laser has an indirect effect
on tissues up to 8-10 mm.
b)The GaAs, which has a longer wavelength, is directly absorbed in tissues at depths of 1-2 cm and has an
indirect effect up to 5 cm

24. Clinical application of laser
 Laser treatment techniques
There are two main techniques :
1. Contact technique: GaAs only for trigger points or around wound.
2. Non-contact technique: for HeNe and GaAs for superficial wounds or stimulation of wound bed

25. Thank you!