Low level laser therapy uses low-powered lasers to stimulate healing. It can be used to treat wounds, pain, and other conditions. There are two main types - high-powered "hot" lasers that use thermal effects, and low-powered lasers that produce no heat. Low-powered lasers are classified by safety class and can be He-Ne or Ga-As lasers. Laser therapy stimulates healing through biostimulation effects. It may increase cell proliferation, collagen production, and phagocytosis. Studies show it can help reduce pain, promote fracture healing, and improve wound healing outcomes. Parameters like dosage, wavelength, and application technique are important to achieve therapeutic effects.

1. LOW LEVEL LASER THERAPY

2. Laser is a form of electromagnetic energy that has wave length and frequency
that fall with in IR and visible light portions of ELECTROMAGNETIC SPECTRUM

3. ❑ Laser can be categorized as either high power or
low power, depending on the intensity of energy
they deliver.
❑ High power laser are also known as HOT LASERS
because of the thermal responses they generate.
❑ These are used in surgical cutting , coagulation
,ophthalmologic, dermatologic, oncologic, and
vascular specialities.

4. ❑low power lasers for wound healing and pain
management is a relatively new area of
application in medicine.

5. ❑Low level devices are considered any laser
that does not generate an appreciable thermal
response.
❑Low power laser produce less than500mv of
power.

6. HISTORY
• Einstein in 1916 discoved LASER.
• The first work with amplified electromagnetic
radiation dealt with microwave amplification
of stimulated emission of radiation(MASER).
• In 1955 Townes and Schawlow showed that it
was possible to produce stimulated emission
of microwaves beyond the optical region of
electromagnetic spectrum

7. First working optical MASER was constructed in
1960 by THEODORE MAIMAN when he
developed the synthetic laser.

8. • After 1965 term LASER(Light Amplification by
Stimulated Emission of Radiation)
was substituted of OPTICAL MASER.

9. Properties of LASER
COHERENCE: All photons of light are of same
wave length
MONOCHROMATICITY: single colour
COLLIMATION: There is minimal divergence of
the photons, thus concentrating a beam of
light

10. LASER CLASSIFICATION
Class 1 lasers are considered non hazardous to
the body. These are invisible lasers devices.
The invisible IR lasers should contain an
indicator light to identify when the laser is
engaged.

11. Class 2 are hazardous only if a viewer stares
continuously into the source.

12. Class 3 can cause retinal injury with in the
natural reaction time. Operator and patient
are required to wear protective eye wear.
❑ these lasers cannot cause serious skin
injury

13. Class 4 present a high risk of injury and can
cause combustion of flammable materials.
Other dangers are diffuse reflections that may
harm the eyes and cause serious skin injury from
direct exposure.

14. Argon laser blue
He-Ne laser red COMMONLY USED
Ruby laser
Ga-As laser COMMONLY USED
Neodymium Yag Laser
CO2 laser

15. PRODUCTION
❑Laser consists of a gain medium , which
is a material (gas ,liquid, solid) with
specific optical properties contained
inside an optical chamber.

16. • When an external power source is
applied to the gain medium photons are
released, which are identical in phase,
direction and frequency

17. ❑To contain them, and generate more photons,
mirrors are placed at both ends of the
chamber.
❑One mirror is totally reflective, where as the
other is semi transparent.

18. • The photons bounce back and forth reflecting
between the mirrors, each time passing
through the gain medium ,thus amplifying the
light and stimulating the emission of other
photons.

19. ❑Eventually, so many photons are stimulated
that the chamber cannot contain the energy.

20. ❑When a specific level of energy is attained,
photons of a particular wavelength are ejected
through the semi transparent mirror
appearing as a beam of light.

21. • Thus ,amplified light through stimulated
emissions(LASER) is produced.

22. Gain medium

23. Depth of penetration
❑Energy applied to the body can be absorbed,
reflected ,transmitted and refracted.
❑Biological effects result only from the
absorption of energy, and as more energy is
absorbed, less is available to for deeper and
adjacent tissues.

24. ❑Absorption of He-Ne laser energy occurs
rapidly in the superficial structures especially
with in the first 2-5 mm of soft tissue.
❑The response that occurs from absorption is
termed as direct effect. The indirect effect is a
lessened response that occurs deeper in the
tissues.

25. ❑The normal metabolic processes in the deeper
tissues are catalyzed from the energy
absorption in the superficial structures to
produce the indirect effect.

26. Direct
He-Ne 2-5mm
Ga-As 1-2cm
Indirect
He-Ne 8-10mm.
Ga-As 5cm

27. ❑Therefore, GaAa LASER has better potential for
the treatment of deeper soft tissue injuries, such
as strains, sprains, and contusion.

28. direct
indirect

29. PREPARATION OF PATIENT
WOUND
❑The wound should be cleaned appropriately
and all debris are removed.
❑Heavy exudate that covers the wound will
diminish the lasers penetration

30. ❑Facial laceration can be treated with laser,
although care should be taken not to direct the
beam into patients eye.
❑Risk of retinal damage from the low power
lasers used is low

31. PAIN
Diagnose the pains etiology
While treating trigger point , probe should be
held perpendicular to skin with slight contact
Ligament treatment keep laser probe in contact
and perpendicular to that structure

32. • When treating a joint , the patient should be
positioned so that the joint open to allow
penetration on energy to intra articular areas

33. LASING TECHNIQUES
• Gridding
• Scanning
• Wanding

34. LASING RULES
❑To administer a laser treatment, the tip should
be in light contact with the skin and directed
perpendicular to the target tissue while the
laser is engaged for the designated time

35. Gridding
❑Commonly a treatment area is divided into a
grid of square centimeters, with each square
centimeter stimulated for specified time.
❑Lines and points should not be drawn on
patients skin because this may absorb some
light energy

36. ❑open areas are to be treated with a sterilized
clear plastic sheet placed over the wound to
allow surface contact

38. SCANNING TECHNIQUE
❑ scanning technique in which there is no
contact between the laser tip and skin. With
this technique the applicator tip should be
held 5 to 10 mm from the wound

41. ❑ Not recommended to treat at distance greater
than 1 cm.
❑ Because beam divergence occurs the amount
of energy decreases as the distance from
target increases.
❑ The amount of energy lost becomes difficult
to quantify accurately if the distance from the
target is variable.

42. WANDING TECHNIQUE
❑Grid area is bathed with the laser in an
oscillating fashion for the designated time.

44. Cluster probe

45. Parameters of low output LASER
He Ne GaAs
LASER TYPE GAS SEMICONDUCTOR
WAVE LENGTH nm 632.8 904
PULSE RATE CONT WAVE 1-1000HZ
PULSE WIDTH CONT WAVE 200nS
PEAK POWER 3mW 2W
AVERAG POWERmv 1.0 0.04-0.4
BEAM AREA cm 0.01 0.07
FDA CLASS CLASS 2 CLASS 1

46. DOSAGE
❑ HeNe laser has 1.0 mW average power
output at the fiber tip and delivered in cont
wave mode
❑GaAs –out put of 2W, average power 0.4mW
when pulsed maximum rate of 1000Hz
❑GaAs has pulse rate of 1000Hz , pulse width of
200ns(ns=10-9)

47. Pulse mode drastically reduce the amount of
energy emitted from LASER
2 W LASER peak power
PULSE 100 Hz
Average power= pulse rate x peak power x pulse width
= 100Hz x 2000mW x (200 x 10-9)

48. Adjustment of pulse rate alters the average
power
In past it was thought that altering the
frequency of laser would increase its benefits.
Recent evidence indicate total number of joules
is more important.
Higher pulse rate are recommended to decrease
the treatment time required for each
stimulation point

49. Dosage or energy density of laser is reported in
the literature as joules /cm2
1J = 1W/s
TA = (E/Pav) x A
TA = treatment time for a given area
E = mJ of energy/cm2
Pav = average laser power in mW
A= beam area in cm2

50. To deliver 1J/cm2
With 0.4 mW avg pwr Ga As laser with 0.07 cm2
beam area
TA= (1000mj/0.4mW) x 0.07cm2
Try 50mj

51. D = P X (T/A)
D = DOSE IN J/CM2
P = LASER OUTPUT IN WATTS
T = TREATMENT TIME IN SECONDS
A = AREA OF THE WOUND MEASURED IN CM2

52. DOSAGE
Wound healing
SUPERFICIAL
• Acute He Ne 0.5 TO 1J/CM2
• Chronic He Ne 4J/CM2
• DEEP TISSUES
• Acute GaAs 0.05 TO 0.1 J/CM2
• Chronic GaAs 0.5 TO 1J/CM2

53. BIOSTIMULATION EFFECT
❑The Arndt-Schultz principle may explain the
apparent biologic response to low energy He-
Ne Laser irradiation
❑This biologic principle theorizes that tissues
react to the amount of energy absorbed per
unit time.
Weak stimuli excite physiologic activity
Moderately strong stimuli favor it
Strong stimuli retard physiologic activity
Very strong stimuli arrest physiologic activity

54. ❑Klein-Kort and Foley cite a second possible
theory for mechanism of action of low
powered laser of bio stimulation
❑They postulated that the low intensity Laser
can stimulate energy stores via ATP formation
and activation of enzyme activity

56. CLINICAL APPLICATON OF LASER
Wound healing
Fibroblast proliferation- collagen , epithelial and
chondrocytes
Tensile strength
Increased lased wounds are confirmed
Wound contraction, collagen synthesis and
increase in tensile strength are fibroblast
mediated functions

57. Immunologic Response
Laser irradiation caused increased phagocytosis
by leukocytes with dosages of 0.05J/cm2
This led to the possibility of bactericidal effect
Inflammation
Biopsies of experimental wounds were
examined for prostaglandin activity to
delineate the effect of laser stimulation on the
Inflammatory process

58. Decrease in prostaglandin is a proposed
mechanism for promoting the reduction of
edema through laser therapy
Scar tissue
Macroscopic examination of healed wounds was
subjectively described after the laser
experiments.
The wounds exposed to laser irradiation had less
scar tissue and a better cosmetic appearance

59. PAIN
Effective in reducing pain and have been shown
to affect peripheral nerve activity
Bone response
Promotes fracture healing

60. Contra indication
Cancerous tumors
Directly over eyes
Pregnancy
Cancerous growth

61. Evidence

62. Laser therapy for venous leg ulcers
Cochrane Database of Systematic Reviews
1999, Issue 1. Art. No.: CD001182. DOI: 10.1002/14651858.CD001182.
Result
• There were four eligible trials. Two RCTs compared
laser therapy with sham, one with ultraviolet therapy
and one with non-coherent, unpolarised red light.
• Neither of the two RCTs comparing laser with sham
found a significant difference in healing rates; there
was no significant benefit for laser evident

63. Current indication of LLLT in plastic
surgery(review)
Hersant B et al . Photomed LASER surgery.2015
• 13 studies on animals showed that LLLT had
efficacy in the improvement of falp survival.

64. Collagen Production in Diabetic Wounded
Fibroblasts in Response to Low-Intensity
Laser Irradiation at 660 nm
Diabetes Technology & Therapeutics. December 2012,
14(12): 1110-1117. doi:10.1089/dia.2012.0125.
Results
• Diabetic wounded cells irradiated with
5 J/cm2 at 660 nm showed a significant
increase in cell migration, viability,
proliferation, and collagen content.

65. Effect of Laser Irradiation at Different
Wavelengths (940, 808, and 658 nm) on
Pressure Ulcer Healing: Results from a
Clinical Study
Taradaz & halski et al 2013
• The laser therapy at a wavelength of 658 nm
appeared to be effective at healing pressure
ulcers. The wavelengths of 808 and 940 nm
did not have any effect in our study.

67. Practical demonstration