The purpose of this study was to examine the effects of laser therapy on wound healing processes in vitro. Day 16 Fetal mouse limbs (n=139) were wounded using a standardized full thickness excision, and placed into a serum free organ culture system. All limbs received daily one minute laser treatments for 3 to 7 days at one of the following intensities: 0 (Sham), 0.23, 1.37, 2.75, 3.66, and 4.58 J/cm2 from a Gahium Arsenide (Ga-As) 904nm laser. The results showed that laser treatment, at an energy density of 0.23 and 1.37 J/cm2, significantly augmented the change in wound size, wound closure rate, and wound appearance in a dose dependent manner. Collagen deposition in the bone and dermis of wounded fetal mouse limbs was greatest in limbs that were treated with certain doses of laser (0.23, 2.75, and 3.66 J/cm2). Administration of higher doses of laser (4.58 J/cm2) was detrimental to both the photographic and histological appearance of the wound. We conclude that laser therapy, when delivered at an appropriate energy density, can directly promote wound healing processes.
The effectiveness of laser therapy in accelerating wound healing has been clinically well documented. We used two devices: one, a He-Ne laser with a wavelength of 632.8nm and power output of 8mW; the other, a Ga-Al-As laser with a wavelength of 830nm and power output of 120mW. The indication for treatment was stasis ulcers (Ulcer cruris) due to chronic venous insufficiency syndrome. Sixty-two patients were treated in this study. The challenge of obtaining good results when treating patients with long-standing vascular ulcers and wounds caused us to explore this technique. We achieved complete wound healing, classified as good, in 53 patients (85.48%) of the patients during a two to 14 week period of treatment, and moderate partial wound closure with clinical improvement in 4 patients (6.46%) with chronic long-term venous leg ulcers. The efficiency of the treatment was 91.94%. No patient had to stop treatment because of adverse side effects. Two patients (3.2%), had recurrent ulcers. These findings indicate that appropriate doses of laser can be beneficial in promoting tissue repair.
The purpose of this study was to determine the effects of laser therapy in pain reduction and/or recovery of patients at the onset of Rheumatoid Arthritis (RA), comparatively with the traditional nonsteroidal anti-inflammatory drugs (NSAIDs). Fifty-nine patients with RA of 6-12 months duration were included in the study. The patients were divided into 3 groups: Group 1 (21 patients) received laser therapy; Group 2 (18 patients) was submitted to placebo laser therapy and NSAIDs medication; Group 3 (20 patients) was treated only with NSAIDs. Physical therapy was instituted in all three groups. GaAIAs diode laser of 830 nm wavelength and 200 mW maximum output power was used. Group 1 received laser therapy once each day, eight days per month, for a total of 32 treatments during a four-month period. The parameters used were 2-4 J/cm2 energy density, and a frequency of 5 Hz or 10 Hz depending on the number and severity of pain in the affected joints. Placebo laser treatment was given to group 2. The functional activity score, the acute phase reactants (ESR and C - reactive protein), T - lymphocytes and NK (natural killer) - cells were estimated. Synovial biopsies and Magnetic Resonance Imaging (MRI) of the synovial membrane were performed as well. The analysis of the clinical and biological parameters at the end of treatment showed a statistically significant decrease of duration of morning stiffness, of pain at rest and during movements, and improved acute phase reactants. The overall efficacy rate in these studies was 86% in the fttst group, 50% in laser placebo group and 40% in the NSAIDs-treated third group. After four months of treatment, our investigations showed that 830 nm infrared laser therapy promoted the restoration of function, relieved pain and limited the complications of RA.
A number of clinical studies have reported the efficacy of the 820 nm Gallium Aluminum Arsenide (GaAlAs) laser for the management of musculoskeletal pain, but its mode of action is not clear. The aim of this study was to investigate the effect of 820 nm GaAlAs at energy densities of 4 J/cm2 and 19 J/cm2 on prostaglandin E2 (PGE2) production by myoblast cultures undergoing stimulation with interleukin I alpha (IL-1). The differentiated C2C12 cultures were allocated randomly into 6 groups (6 samples per group). Each group, except the control and the IL-1 supplement groups, was jrradiated with 820 nm GaAIAs at energy densities of 4J/cm2 or 19 J/cm2 on three occasions. The irradiation was undertaken initially and at one hour and two hours. The difference in mean PGE2 at 12 hours among the 6 groups was statistically significantly different as compared by Analysis of Variance, p=0.0001. The result from Scheffe multiple comparison (p = 0.05) showed that the PGE2 production of the culture with IL-1 and the culture with IL-1 irradiated by 820 nm at 4 J/cm2 were higher than the control group. There was no statistically significant difference in PGE2 production among the control group, the laser-irradiated groups without IL-1 supplement and the IL-1 stimulation group irradiated by 820 nm at 19 J/cm2. The results indicate that IL-1 can stimulate PGE2 synthesis in differentiated C2C12 skeletal muscle cells. 820 nm laser irradiation at 19 J/cm2 was found to inhibit that mechanism, while the lower energy density (4 J/cm2) failed to inhibit PGE2 production.
It is well accepted that with lasers, there are two modalities of treatment. One is the use of the photobiodestructive effect, as for example, in laser surgery where high reactive level laser therapy (HLLT) is used as a scalpel, and the other is the use of the photobioactivating effect, otherwise known as low reactive level laser treatment or laser therapy (LLLT)(1-8). Since October 1996, we have performed laser therapy as an adjunctive treatment to 73 female patients being treated for infertility either by artificial insemination or by other assisted reproduction treatments (ART). The average age of the patients was 39.3 years, the average period of treatment prior to this study was 8.98 years. The average number of ART was 15 times. Two types of lasers; the 632.8nm, helium-neon laser and the 830nm diode laser were used in this study. An average of 21 laser treatment sessions was performed on the patients resulting in 14 confirmed pregnancies and 11 live births.