Abstracts from (8/10-98)

"How negative are the negative studies?" Tunér J, Hode L.
It¹s all in the parameters: a critical analysis of some well-known negative studies on low-level laser therapy. J Clinical Laser Med & Surg. 1998; 16 (5): 245-248.

Studies failing to find any effect of LLLT are often used as support for the alleged non-efficacy of LLLT. The authors have selected some of the most quoted negative  studies and analyzed them. It turns out that the failure to find an effect too often depends on mistakes in the design of the studies. Doses in the range 0.0007 - 0.1 J have been used for a variety of indications where therapeutic doses are 100 times or more. Patients with psycosomatic pain have been treated,  HeNe laser has been used as a "placebo" laser, treatment technique has been inadequate, powers density extremely low, calculation of dosages incorrect, systemic effects and tissue condition have been disregared etc. Meta-analyses disregarding such pitfalls are also less useful. A combined knowledge of physics and medicine seems to be an important factor in the design of LLLT studies.

LLLT in male genital disorders
Gasparyan L et al. Low level laser therapy of male genital tract chronic inflammations. Proc. 2nd Congress World Association for Laser Therapy, Kansas City, USA, September 2-5 1998; p. 82-83.

Male genital tract chronic inflammations were treated by combinations of transdermal, transrectal (prostate gland) and intravenous HeNe laser irradiation. The energy of a 2 mW HeNe laser was applied via a light guide into a vein. The projections of the male genital organ and the inguinal areas were irradiated with a 890 nm 5W peak power cluster probe. For the transrectal prostate gland irradiation a 890 nm 15W peak power laser was used. 36 patients were given conventional medical therapy and another 36 were given LLLT in combination with medical therapy. Clinical and laboratory findings were statistically better in the LLLT group and relapse rate was lower. It is suggested that LLLT increases the local circulation and thus also improves the effect of antibiotics.

Bürgers disease improved by laser therapy
Sasaki K et al. Low level laser therapy (LLLT) for thrombonagitis obliterans. Proc. 2nd Congress World Association for Laser Therapy, Kansas City, USA, September 2-5 1998; p 95-96 .

In this case report a patient with thrombonagitis obliterans (Bürgers disease) was treated with a 60 mW 830 nm laser and a defocused 20 W Nd:YAG laser. Ulcers were remarkably improved. Agonizing pain and ischemia were relieved. In the MRA findings, sudden arterial obliteration disappeared. In the thermographical findings, skin temperature increased to normal level.

LLLT in the dental clinic
Pinheiro A et al. Low-level laser therapy is an important tool to treat disorders in the maxillofacial region. J Clinical Laser Med & Surg. 1998; 16 (4): 223-226.

241 patients with different disorders in the maxillofacial region were treated with LLLT. Indications were temporomandibular disorders, trigeminal neuralgia, muscular pain, aphtae etc. Lasers of 633, 670 and 830 nm were used. Most treatments consisted of a series of 12 applications (twice a week). Average dose was 1.8 J/cm2. At the end of treatment 154 patients were asymptomatic, 50 improved considerably and 37 were symptomatic.

Laser is effective for medial and lateral epicondylitis
Simunovic Z, Trobonjaca T et al. Treatment of medial and lateral epicondylitis - tennis and golfer¹s elbow - with low level laser therapy: a multicenter double blind, placebo controlled clinical study of 324 patients. J Clinical Laser Med & Surg. 1998; 16 (3): 145-151.

In a two center study 324 patients with unilateral medial or lateral epicondylitis were treated with LLLT. Trigger points were treated with 830 nm.  633 and 904 nm in combination was used in the scanning mode. Total pain relief was obtained in 82% of the acute cases and 66% in the chronic cases. A combination of trigger points (TP) and scanning was more effective than TP alone and TP alone were more effective than scanning alone. One of the centers had slightly less powerful lasers and the outcome was a bit lower, although the dosage was the same in both centers.

HeNe laser reduces mucositis
a) Barasch B et al. Helium-neon laser effects on conditioning-induced mucositis in bone marrow transplantation patients. Cancer. 1995; 76 (12): 2550-2556.

Oral mucositis is a common complication of bone marrow transplantation conditioning therapy. Different drugs are given in order to reduce rejection of the implant. These drugs induce an oral mucosits. The mucositis is painful and complicates nutrition. Sometimes the intake of the drug has to be stopped due to complications.  In the study above 20 patients received HeNe to their oral mucosa, either right or left of midline. One side was sham irradiated.  Laser treatment was well-tolerated and reduced the severity of oral mucositis.

b) Cowen D et al. Low energy helium-neon laser in the prevention of oral mucositis in patients undergoing bone marrow transplant: results of a double blind randomized trial. Int J Radiat Oncol Biol Phys. 1997; 38 (4): 697-707. Significant reduction of oral mucositis using a 60 mW HeNe laser

“Medium Level Laser Therapy (MLLT)”?
The advent of “high power low-power laser” tests the validity of the term “Low Level Laser Therapy”. We have seen a rather slow power output development from the early commercial equipments, using sometimes only a couple of mW. With the advent of the GaAlAs diode, the output powers of these lasers have increased rapidly. 30 mW used to be a rather high power; then there were lasers of 100 and even 200 mW. Now we have GaAlAs lasers of 500 and even 1 000 mW commercailly available. Is this still “Low-power” laser? Yes and no. The fact that we are using 1 000 mW does not necessarily mean that we use higher doses. 1-4 J/cm2 is still a normal dose. But to reach that dose in seconds is quite something! And since the energy density is considerably higher, we might obtain better effects. And we are also able to reach deep lying tissues, previously hardly within reach of the early lasers.  So, are we still using “Low Level” lasers? Or should we coin the term “Medium Level Laser Therapy (MLLT)”? There is so far scarse literature on these high powered lasers. Hoteya et al (Report on the first IALSM Meeting. Laser Therapy. 9 (4): 185) reports on the use of a 1 W GaAlAs laser (670 mW/cm2) in the field of orthopedics. When using it in a group of patients with chronic pain, the efficacy rate was 75.5% and the “no change” was 24.5%. Another earlier double-blind study for the same indication, using a 150 mW GaAlAs laser resulted in an efficacy rate of 70.6%. So the outcome is more or less the same. But treatment time must have been considerably reduced. In conclusion it can be said that the advent of “MLLT” seems very promising and practical but there is a great need of controlled studies.

New hope for patients with spinal cord injuries.
Rochkind S, Shahar A. Nevo Z.  An innovative approach to induce regeneration and the repair of spinal cord injury. Laser Therapy.1997; 9 (4): 151. An Israeli research group has investigated an innovative method of repairing injured spinal cords. In a rat model the spinal cords were transected in 31 animals (between T7/T8).  In vitro constructed composite implants were used in the transected area. These implants contained embryonal spinal cord neuronal cells dissociated from rat fetuses, cultured on biodegradable microcarriers. After being embedded in hyaluronic acid the implants were ready to be placed into the injured area. The whole lesion area was covered with a thin coagulated fibrin-based membrane. Control animals underwent the same laminectomy but did not receive any implant. In all animals the wound was closed normally. Laser therapy was started immediately after surgery. It was continued daily for two weeks using 780 nm, 200 mW, 30 minutes daily.  One group received the implant but no laser. During the 3-6 months follow up, 14 of the 15 animals that received laser (A) showed different degrees of active movements in one or both legs, compared to 4 of 9 animals in the group who had received implants but no laser (B). In the group receiving no implant and no laser (C), 1 out of 7 showed some motor movements in one leg. Somatosensory evoked potentials were elicited in 10 of the 15 rats in group A at three months, and on one side in one animal in group B. Axon sprouting was observed as soon as three days post surgery, in group A only.

Abstracts from (22/7-98)

LLLT improves nerve injuries
Dr. Shelley M Khullar of the Department of Oral Surgery, Faculty of Dentistry, Oslo, Norway presented her dissertation in February 1997. The title of the dissertation is ”Reinnervation after nerve injury: The effects of low level laser treatment”. The conclusion of the five published studies are: *A course of 20 LLL treatments using a GaAlAs laser (=820 nm) on an area of long-standing paraesthesiae in the orofacial region induced an objectively evaluated  significant improvement in fine mechanosensory perception and a decrease in the area of paraesthesiae. *The significant improvement in mechanosensory perception was also perceived as a subjective improvement by the patients. *A course of 20 LLL treatment with a GaAlAs laser (=820 nm) induced no change in thermoperception in an area of paraesthesiae. *Daily LLL treatment over a 28 day period, with a GaAlAs laser accelerated motor nerve reinnervation as assessed by return of motor function subsequent to a standardised axonotmesis injury in the rat sciatic nerve. *LLL treatment with a GaAlAs (=820 nm) laser enhanced sensory reinnervation of peripheral target tissues subsequent to an IAN axotomy injury in the rat model. The findings are demonstrated immunohistochemically by the presence of CGRP positive neurones.

Biomodulation of normal and tumor cells
J Photochem Photobiol B: Biology. 1997; (40): 253-257 In a study by Schaffer et al. various cells were irradiated by 805 nm laser light.  The cells were (1) murine skeletal myotubes, (2) normal urothelial cells, (3) human squamous carcinoma cells of the gingival mucosa and (4) urothelial carcinoma cells. Mitotic index for 1, 2 and 4 increased at fluences of 4 J/cm2 while irradiation at 20 J/cm2 resulted in a slight decrease. The no 3 cells showed a decrease of the mitotic index with both fluences. The most interesting observation is the different reaction of the two carcinoma cells.

Promising results using LLLT for tinnitus and inner ear diseases Auris Nasus Larynx. 1997; 24 (1): 39-42.
Shiomi et al. used a 40 mW GaAlAs laser in a group of 38 patients suffering from tinnitus, resistant to several medical therapies for more than six months. 21.6 J was given each time through the auditory meatus toward the cochlea. Ten treatments or more were given. Only 26% of the patients reported improved duration, but 58% had  reductiont of loudness and 55% reduced annoyance. The authors conclude: ”Laser therapy seemed to be worth trying on patients with intractable tinnitus”. Editorial note: The results can be improved if much higher doses are given. Dr. Lutz Wilden of Bad Füssing, Germany reported on his 6 years of experience at a recent lecture before the members of the Swedish Laser Medical Society (Stockholm, May 1998). Dr. Wilden is using three different lasers. One is directed through the meatus, two are positioned over the mastoid. Total dosage 2000-4000 (sic) joules per treatment (60 minutes per session, 30 minutes per ear). Doses may seem very high, but the thick bone behind the ear absorbs about 95% of the energy before reaching the inner ear. For more info, see http://home.t-online.de/gbl-hc/ez.

Laser therapy plays a role in bone healing
Lasers Surg Med. 1998; 22: 97-102.
Luger et al. studied the effect of HeNe laser on the healing of tibial bone fractures in rats.   63 J (35 mW) was given  transcutaneously daily over the fracture area. After 4 weeks the tibia was removed and tested at tension up to failure. The maximal load at failure and the structural stiffness of the tibia were found to be elevated significantly in the irradiated group, whereas the extension maximal load was reduced. In addition, gross non-union was found in four fractures in the contol group, compared to none in the irradiated group.

GaAlAs laser treatment evaluated for trigeminal neuralgia, paresthesia, atypical facial pain and temporo-mandibular joint pain in a 5 year study. - Tandlægebladet.
1994; 98 (2): 526-529.
In Danish. - Eckerdal A, Lehmann Bastian H. Can low reactive-level laser therapy be used in the treatment of neurogenic facial pain? A double-blind, placebo controlled investigation of patients with trigeminal neuralgia. Laser Therapy. 1996; 8: 247-252. At the Odense University Hospital, Denmark, Arne Eckerdal has evaluated the effect of 830 nm, 30 mW, laser treatment for a number of indications. Patients suffering from trigeminal neuralgia (n = 36) had a positive result in 81% at the end of treatment, 42% at 1-year control. Patients having received previous alcohol blocks (n = 14) responded less favourably to the treatment. 50% were pain free at the end of the treatment period, 20% at 1 year control. Patients with non-specific facial pain (n = 63) were pain free at the end of treatment, 44% at follow up one year later.  In a group of 22 patients with paresthesias (n = 22), only 5 were successful at end of treatment , 4 were improved and 13 were not improved.  The result at 6 and 12 months were the same.   Patients with temporo-mandibular pain (n = 40) were improved in 73% and at 1 year control still 70% were pain free.

Can HeNe laser improve fertility?
Abstracts LASERmed 97;  p. 138, no 112 The fertilizing potential of mouse spermatozoa was positively affected by HeNe laser in vitro. Cohen et al at the Bar-Ilan University, Israel found that the Ca2+ uptake, mainly in the mitochondria, was improved after LLLT. The results suggest that the effect of 630 nm laser irradiation id mediated through the generation of hydrogren peroxide by the spermatozoa and that this effect plyas an important role in the augmentation of the sperm cell’s capacity to fertilize in vitro.

Are there ”good” and ”bad” free radicals?
Abstracts LASERmed 97; p. 138, no 110
There is considerable evidence that photobiostimulation proceeds via enhanced production of reactive oxygen species (ROS) by the photoexcited respiratory chain. Increased amounts of free radicals are produced in the blood of patients with acute respiratory illness or leukemi. However, irradiation with 633 or 830 nm reduces the amount of free radicals produced in the anomalous blood cells. Friedmarn and Lubart therefore suggest two categories of free radicals: 1. the ”good” ones, which may produce biostimulation and which tentatively would be the superoxide anion radicals. 2. the ”bad” ones, which collectively are designated by R. The reduction of the quantity of free radicals by LLLT is then ascribed to the reaction R + O2- = R- +O2 It is possible that many of the therapeutic effects of low-power laser irradiation are due to this reaction.

GaAs is effective in chronic low back pain.
Two abstracxts from Lasers Surg Med. 1998; Suppl. 10, p. 6 1)Prof. Soriano in Rosario, Argentina, performed a double blind trial with elderly people suffering from chronic low back pain. After a through medical examination the patients were divided into two groups. One received GaAs 4J per point and one received sham irradiation. Ten consecutive sessions were done, one every day. Pain was evaluated through a VAS scale at the beginning and at the end of the treatment period. Treatment was effective in 71% in the laser group and 36% in the sham gruop. The pain disappeared completely in 45% in the laser group and 15% in the sham group. During the follow up 35% of the patients in the laser group who had relieved their pain more than 60% relapsed, compared to 70% in the control group. There were no side effects. 2)Effects of low energy laser therapy on herniated lumbar discs. Gruszka M et al. Gruszka (Buenos Aires)  treated 15 patients with one or more protruded lumbar disc herniations with GaAs 904 nm, with a dose of 9J on each point, 20 to 25 points on the lumbar spine and on referred radicular pain points, 3 to 5 times a week during 4 months. Pain was relieved in 100%, gait and neurological signs improved in all patients, EMGs improved and CAT scans showed less protrusion of the herniated discs.