Acne vulgaris is adebilitating dermatologic disease, and is conventionally treated by laser therapy using a microring resonator system. An evolving understanding of laser-tissue interactions involving Propioni bacterium acneproducing porphyrins, and the development of lasers to target the sebaceous glands, has led to the development of an escalating number of laser light for acne treatment. The results show that the full width at half maximum of the proposed laser pulse of 0.15 nm can be generated using a microring resonator system. The power of the laser is 200 W and the wavelength laser is 1,032 nm, which is proposed as a treatment of acne vulgaris diseases.
A microring resonator (MRRs) system incorporated with a add/drop filter is proposed in which ultra-short single, multi-temporal, and spatial optical soliton pulses are simulated and used to kill abnormal cells, tumors, and cancer. Chaotic signals are generated by a bright soliton pulse within a nonlinear MRRs system. Gold nanoparticles and ultra-short femtosecond/picosecond laser pulses' interaction holds great interest in laser nanomedicine. By using appropriate soliton input power and MRRs parameters, desired spatial and temporal signals can be generated over the spectrum. Results show that short temporal and spatial solitons pulse with FWHM = 712 fs and FWHM = 17.5 pm could be generated. The add/drop filter system is used to generate the high-capacity, ultra-short soliton pulses in the range of nanometer/second and picometer/second.
Low-energy laser irradiance at certain wavelengths is able to stimulate the tissue bio-reaction and enhance the healing process. Collagen deposition is one of the important aspects in healing process because it can increase the strength of the skin. This study was designed to examine the biophotonic effect of irradiance on collagen production of diabetic wound in rat model. The tensile strength of skin was employed as a parameter to describe the wound. Diabetic rat models were induced by streptozotocin via intravenous injection. Skin-breaking strength was measured using an Instron tensile test machine. The experimental animals were treated with 808-nm diode laser at two different powers-0.1 and 0.5 W/cm(2)-and 30, 60, and 120 s for each session. The tensile strength was optimized after treated with high-power diode laser. The photostimulation effect was revealed by accelerated healing process and enhanced tensile strength of wound. Laser photostimulation on tensile strength in diabetic wound suggests that such therapy facilitates collagen production in diabetic wound healing.
The aim of this study is to examine the effectiveness of transmeatal low-power laser stimulation (TLLS) in treating tinnitus. This is a prospective, double-blinded, randomized, placebo-controlled trial. Patients with persistent subjective tinnitus as their main symptom were recruited into the study from the outpatient clinics. The recruited patients were randomized into the experimental group or TLLS+ group (patients in this group were prescribed to use TLLS at 5 mW at 650 nM wavelength for 20 min daily and oral betahistine 24 mg twice per day for a total of 10 weeks) and the control group or TLLS- group (patients in this group were prescribed with a placebo device to use and oral betahistine 24 mg twice per day for 10 weeks). All patients were required to answer two sets of questionnaires: the Tinnitus handicap inventory (THI) and visual analogue scales (VAS) symptoms rating scales, before starting the treatment and at the end of the 10-week treatment period. The total score of the THI questionnaire was further graded into five grades, grade 1 being mild and grade 5 being catastrophic. Wilcoxon-signed ranks test and Mann-Whitney test were used to compare and analyze the THI and VAS scores before and after treatment for each group. Changes with p value of <0.05 were considered as statistically significant. Chi square test was used to analyze the change of parameters in categorical forms (to compare between TLLS+ and TLLS-). Changes with p value of <0.05 were considered as statistically significant. Forty-three patients successfully and diligently completed their treatment. It was noted that using any condition of the device, TLLS+ or TLLS-, patient's tinnitus symptoms improved in terms of THI scores (TLLS+, p value = 0.038; TLLS-, p value = 0.001) or VAS scores with a change of at least one grade (TLLS+, p value = 0.007; TLLS-, p value = 0.002) at p value <0.05 significant level. In contrast when TLLS+ group was compared with TLLS- group, no statistically significant result was obtained. In term of VAS scores, there seems to be no statistically significant improvement in patients' annoyance, sleep disruption, depression, concentration and tinnitus loudness and pitch heard between the two groups. Transmeatal low-power laser stimulation did not demonstrate significant efficacy as a therapeutic measure in treating tinnitus.
Study site: Otorhinolaryngology clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
The photobiostimulation effects of near infrared 808 nm diode laser irradiance on diabetic wound were investigated. 120 rats were induced with diabetes by streptozotocin injection. Full thickness punch wounds of 6mm diameter were created on the dorsal part of the rats. All rats were randomly distributed into four groups; one group served as control group, whereas three groups were stimulated daily with unchanged energy density dose of 5 J/cm(2) with different power density, which were 0.1 W/cm(2), 0.2 W/cm(2) and 0.3 W/cm(2) with different exposure duration of 50s, 25s and 17s, respectively. Ten rats from each group were sacrificed on day 3, 6 and 9, respectively. Skin tissues were removed for histological purpose. The contraction of wound was found optimized after exposure with 0.1 W/cm(2). Based on the histological evidence, laser therapy has shown able to promote wound repair through enhanced epithelialization and collagen fiber synthesis. Generally, irradiated groups were advanced in terms of healing than non-irradiated group.