Reduction in the perception of
pain can be achieved with specific applications of Low Level Laser
Therapy (LLLT) at 830 nm for certain conditions.
The study is a pilot project and was not considered by a review
board (IRB) for the initial phase. Continued investigation is
suggested. The equipment for the study was provided by MicroLite. No
fees for treatment were charged to any patients and no subjects were
paid to participate in the study.
REVIEW OF THE LITERATURE
There are few studies on LLLT and
those that exist rarely distinguish between the various wavelength
devices. According to the Swedish Medical Laser Society Light
Emitting Diode (LED) units are heating devices and seem to take
around 2x the incident dose of LED to produce the effect of the
Laser probe and then to a much shallower depth of penetration. Both
LEDs and LASERs work, but more research must be carried out with
LEDs. LLLT research should not be used to justify LED equipment, or
to infer the benefits of LED therapy (this could apply equally to
pulsed v continuous wave lasers). There are still no investigations
showing that Light Emitting Diode Therapy (LEDT) is as good as LLLT
although many comparisons have been made, also with a different
dose. The depth of penetration depends primarily upon the
wave-length and power density of the beam incident to the tissue,
and the absorption/ reflection characteristics of the irradiated
Another key point is that LED devices are classified by the FDA
with a product code ILY. The Device Description is Infrared lamp.
True laser devices have a product code of NHN. The Device is a lamp,
non-heating, for adjunctive use in pain therapy. The Device
Description is also Infrared lamp. LED devices heat tissue and
sellers of LED devices must warn customers of the hazards of heat
generated by their modality, unlike low-wattage lasers that heal
without heating human tissue.
The primary clinical point of the literature review is that certain
light therapy seems to be a leading cause for remission of pain
generation or of pain perception in both acute and chronic
situations. There is also some evidence of tissue healing rate
affectivity. In conclusion from analyzing these articles, LLLT is
not well understood by those who have investigated the variety of
frequency responses and expectations.
A trial was designed to measure the patient’s perception of pain
and relative improvement on various conditions that cause pain or
have pain associated with them. Patients who had reported persistent
pain were notified of the project and invited to participate. Other
providers of physical medicine were notified as well and encouraged
to have patients with similar painful conditions inquire. All
patients admitted to the study had a history of pain with multiple
episodes of chiropractic manipulation and physical therapy with
various degrees of limited success.
A combination Visual Analogue Pain scale and pain drawing was used
to measure an intake score for each patient and document the
location and type of pain. The Treatment Protocol was the same for
each patient, only the location of the treatment differed based on
the reported area of pain. Depending on the tissue to which the
treatment was applied, three techniques were used: Rotation on
thicker muscular tissue, alignment on tendons and ligaments and
pivot on combination areas. There were 4 men and 7 women ranging in
age between 15 and 83 years of age. Intake measurements include a
visual analogue pain scale from 0 to 10 with 0 representing no pain
and 10 representing the most pain. Patients with complaints of less
than 6 weeks onset were considered in the acute group and those of
more than 6 weeks were in the chronic group. The intake physician
determined each of the following items prior to beginning any
treatment: Treatment foci, the number of foci per complaint, the
nature of the treatment protocol, rotational, alignment or pivot
application of the laser instrument depending on the tissue being
measured. Each focus was treated with 4 joules per cubic centimeter.
Patients were positioned with treatment as closely horizontal to the
heart as possible.
The average intake score was 7.18, and the average exit score was
2.91 on a scale of 0-10 with 0 being no pain and 10 being most pain.
The average intake score of the chronic group was 6.83 and the
average exit score was 3.33 showing a measured average change of 3.5
that equates to an improvement quotient of 51.2%. The average intake
score of the acute group was 7.6 and the average exit score was 2.4
showing a measured average change of 5.2 that equates to an
improvement quotient of 68.4%.
It is noted that every patient in the study perceived some
reduction in pain. It was evident to the staff that the perception
of pain was reduced in most patients after 1 or two sessions of
treatment. It seemed as though the chronic group noted the most
significant changes most rapidly even though their overall change
was less than the acute group; but no measurements were made to
corroborate this. It would be wise in a future study to have the
patients complete a Visual Analogue Pain scale after each session to
see when the most benefit was derived and to determine if 6 sessions
were actually necessary to produce the remission of pain. It seemed
that chronic patients needed less sessions to respond than did the
acute group. This would be very interesting to bear out with future
study as it seems to be opposite of the response to typical non-drug
and non-surgery physical medicine modalities.
The 830nm cold laser treatment delivered in the protocol described
above produces a consistent reduction in the perception of pain at
various foci in patients with a variety of diagnoses. This may be
temporary or permanent; this study could not determine any long
term benefits. Follow-up and additional measurements in
functionality changes are indicated to determine tissue healing,
rehabilitation or recuperation as a result of this modality.
The other literature referenced herein shows a wide variety of
responses. This study specifies one wavelength device and measured
its effect on pain perception. It can be considered that many forms
of light therapy have been studied on the surface and that an
equally wide spectrum of response can be expected.
Under controlled protocol for
specific pain relative to a variety of conditions, the 830nm Cold
Laser device can produce a consistent remission of pain perception
in both acute and chronic situations. Additional study is indicated
to 1) follow-up on patients whose pain is reduced to see if there is
a lasting effect; 2) measure functionality as a part of the initial
considerations; and 3) measure timing of response to treatment by
considering pain tools on each visit rather than just intake and
1. Effects of low-power laser irradiation on cell locomotion in
protozoa. Photochem Photobiology. 2004: 80 (3): 531-534.
2. Pugliese L, Medrado A, Reis S, Andrade Zde A. The influence of
low-level laser therapy on biomodulation of collagen and elastic
fibers. Pesqui Odontol Bras.2003; (4):307-313.
3. Medrado A, Pugliese L, Reis S, Andrade A. Influence of low level
laser therapy on wound healing and its biological action upon
myofibroblasts. Lasers Surg Med. 2003; 32 (3): 239-244.
4. Hopkins J, McLoda T, Seegmiller J, Baxter G, Low-Level Laser
Therapy Facilitates Superficial Wound Healing in Humnas: A
Triple-Blind, Sham-Controlled Study. J Athl Train. 2004:39 (3):
5. Lizarelli R, Marcello O, Mazzetto M, Bagnato V. Low-intensity
laser therapy to treat dentin hypersensitivity: comparative clinical
study using different light doses. Proc. SPIE. 2000; Vol. 4422.
6. Corona S, Nascimento T, Catirse A, Lizarelli R, Dinelli W,
Plama-Dibb R. Clinical evaluation of low-level laser therapy &
fluoride varnich for treating cervical dential hypersensitivity. J
Oral Rehabil. 2003:30 (12): 1183-9.
7. Marsilio AL, Rodrigues JR, Borges AB. Effect of the clinical
application of the GaAlAs laser in the treatment of dentine
hypersensitivity. J Clin Laser Med Surg. 2003; 21 (5): 291-296.
8. Kawalec J S, Hetherington J, Pfennigwerth C et al Effect of a
diode laser on wound healing by using diabetic and nondiabetic mice.
Journal of Foot and Ankle Surgery. 2004; 43 (4): 214-220.
9. Cho H J, Lim SC, Kim S G et al. Effect of low-level laser therapy
on osteoarthropathy in rabbit. In Vivo. 2004;18 (5):585-591.
10. Irvine J, Chong S, Amirjani N, Chan K. Double-blind randomized
controlled trial of low-level laser therapy in carpal tunnel
syndrome. Muscle Nerve. 2004; 30 (2) :182-187.
11. Lapchak P A, Wei J, Zivin J A. Transcranial infrared laser
therapy improves clinical rating scores after embolic strokes in
rabbits. Stroke. 2004; 35 (8): 1985-1988.
12. Silva J, Lacava Z, Kuckelhaus S, Silva L et al. Evaluation of
the use of low level laser and photo sensitizer drugs in healing.
Lasers Surg Med. 2004;34 (5): 45 1-457.
Available at: http://www.ml830.com