A conservative approach for deep dermal burn wounds using polarised-light therapy

Polarized Light Therapy in the Treatment of Wounds: A Review

The most prevalent type of photo therapies are low-level laser therapy (LLLT) and ultraviolet (UV) treatments, which are distinguished by the physical properties of the light employed. However, in latest years, it has been suggested that polarization and an extensive light band including all light spectra are essential aspects in light treatment. Light waves are filtered to align and vibrate in a single plane, resulting in polarized light (PL). Light that has been polarized can penetrate tissues more deeply than light that has not been polarized. The visible light spectrum is very broad. PL varies from other types of light therapy in that it uses a considerably wider spectrum of wavelengths than LLLT or UV. As a result, PLT devices are often less expensive and simple to operate. Since the late 1960s, light therapy has been used to treat anything from neonatal jaundice to psoriasis and vitiligo. Fenyö created a PL source and found that it can stimulate wound healing in a similar way to the low-energy laser. In comparison to the laser, this source of light had numerous gains: lesser prices, fewer hazards, a greater area to be treated, and no sophisticated user expertise. Despite several findings from fundamental research (in vitro, in vivo, and animal trials), practitioners continue to have reservations regarding PL's potency and utility in treating musculoskeletal problems. It is even largely believed that the commercial use of these therapies is validated by a sufficient amount of scientific evidence based on reliable clinical papers. The major goal of this study is to gather information on the use of PL for treatment of various wound types in animal and human investigations.

Distribution characteristics of pathogens in different stages of pressure ulcers and the therapeutic effect of linear polarized polychromatic light combined with silver sulfadiazine cream

To investigate the distribution characteristics of pathogens in different stages of pressure ulcers and observe the application of linear polarized polychromatic light (LPPL) combined with silver sulfadiazine cream in treating varying stages of pressure ulcers. This study comprised 88 patients with pressure ulcers who were enrolled in the department of burn and plastic surgery of our hospital from April 2019 to April 2022. The wound exudates from patients were collected, followed by analyzing the distribution of pathogens in different stages of pressure ulcers. Patients were randomly divided into 2 groups. The first group (n = 44) received LPPL combined with silver sulfadiazine. The other group was intervened with LPPL group only for 2 weeks. The clinical efficacy, condition, and pain in the 2 groups, as well as the healing timeframes for patients were measured at different stages. The findings showed that among 88 patients with pressure ulcers, 62 were infected, and the infection rate was 70.45%. The pathogens that were observed in stage II and III to IV pressure ulcers were mainly Gram-negative bacteria. The total effective rate in the combined group was 90.91%, which was much higher than that of LPPL group (70.45%). Compared with LPPL group, the pressure ulcer scale for healing and visual analogue scale scores in the combined group were markedly lower (P < .05). It is important to note that in LPPL group, the healing time of patients in stage II and stage III to IV in the combined arm were 9.76 ± 2.38 days and 13.19 ± 2.54 days, respectively. The corresponding time in the LPPL group was prolonged to 13.20 ± 3.76 and 18.82 ± 4.17 days, respectively. The main pathogens associated with wound infection in patients with pressure ulcers are Gram-negative bacteria. The curative effects of LPPL combined with sulfadiazine silver cream on patients with pressure ulcer is obviously improved, and the recovery and pain relief are faster while the healing time of pressure ulcer is shorter.

Aesthetic Treatment of Acute Burns of the Face Using Electro-Photobiomodulation

The quicker a second-degree burn wound heals, the less surgery is required. Low-energy laser therapy may expedite the healing of wounds, according to recent literature findings. To establish this, it was decided to carry out a clinical trial on acute burn patients to demonstrate whether electro-photobiomodulation (EPBM) therapy can hasten wound closure, thereby obviating the need for surgery without worsening hypertrophic scarring and contracture. In clinical prospective analysis, 42 acute burn patients with recent burns to the face alone (13) or the face and additional areas (29). Twenty-six males and 16 women were included. All patients received twice-weekly sessions of intense pulsed light (IPL) and radiofrequency for the face and other areas. Clinical assessment showed excellent results in 34 (81%) patients, good results in 6 (14.3%) patients, fair results in two (4.7%) patients, and no poor results were reported. The results of this clinical trial showed that IPL and radiofrequency therapy can rapidly heal deep skin burns without the need for surgery. and lowered the incidence of hypertrophic scarring and contractures. EPBM induces better aesthetic and functional outcomes (particularly in burns of the face).

Effect of Polarized Light Therapy (Bioptron) on Wound Healing and Microbiota in Diabetic Foot Ulcer: A Randomized Controlled Trial

Background: Diabetic foot ulcer (DFU) complications are the most common cause of morbidity in diabetic patients. Bioptron light therapy is a new adjuvant therapy for wound healing. This study aimed to investigate the effect of polarized light therapy on the healing and microbial nature of DFUs. Methods: Forty type 2 diabetic patients with Wagner grade 1 or 2 DFUs were randomly assigned to one of two groups: the light therapy group, which received Bioptron light therapy using the Bioptron lamp for 12 min three times per week, plus standard wound care, or the control group, which received standard wound care only. Both interventions were given over a 2-month period. Wound surface area, volume, and ulcer microbial cultures were all measured before and after the study period. Results: There was a significant reduction in ulcer surface area between groups in favor of the light therapy group, with a relative ulcer size reduction of 51.44% ± 23.76% compared with 24.5% ± 9.6% in the control group (p < 0.001). Besides, a significant difference was observed between groups in the microbial cultures (p = 0.02); by the end of the 8th week, the number of patients with negative ulcer culture was 12 (60%) in the light therapy group compared with 3 (15%) in the control group. Conclusions: Bioptron light therapy seems to be an effective therapeutic intervention combined with standard care in decreasing wound size and reducing ulcer microbiota for DFUs. It reduces ulcer bacterial infection and speeds up ulcer healing. Trial registration: ClinicalTrials.gov: NCT04446767.

Effect of 632 nm He-Ne Laser on Gram-Positive Bacteria in Deep Partial Thickness Pediatric Burn: A Prospective Double-Blind Randomized Controlled Trial

Background. Burns are one of the most common injuries in pediatric population, gram-positive bacteria is the main pathogens responsible for wound infection that is the leading cause of morbidity and sometimes mortality in growing children with burn. Low level laser is a new treatment option that is increasingly used in the field of wound healing. Aim. To investigate the effect of He-Ne laser on gram-positive bacteria and healing time of deep second-degree pediatric burn. Methods. Thirty children of both genders aged from 2 to 9 years old with 2nd degree upper limb burn infected with gram-positive bacteria participated in this study. They were randomly assigned into two equal groups; either the control group (group A) received systematic antibiotic and 10 minutes’ placebo laser light, or the laser group (group B) received 632 nm laser light, 6 J/cm2 scanning technique for 10 minutes. All patients received regular wound care (dressing). The study protocol was once a day, 3 times / week for one month. Pre and post-treatment evaluation of wound culture and the healing time was recorded for both groups. Results. Wound culture of all children in both groups were negative after two weeks of the study and wound healing time was significantly shorter in the laser group (14.6±5.7 days) than the control group (27±7.3 days). Conclusion. He-Ne laser is an effective option of treatment for 2nd-degree pediatric burn as it has a bactericidal effect on gram-positive bacteria and accelerates wound healing process significantly.

Polarized light therapy: Shining a light on the mechanism underlying its immunomodulatory effects

This study investigates the immunomodulatory effects of polychromatic polarized light therapy (PLT) on human monocyte cells. While there is some evidence demonstrating a clinical effect in the treatment of certain conditions, there is little research into its mechanism of action. Herein, U937 monocyte cells were cultured and exposed to PLT. The cells were then analyzed for change in expression of genes and cell surface markers relating to inflammation. It was noted that 6 hours of PLT reduced the expression of the CD14, MHC I and CD11b receptors, and increased the expression of CD86. It was also shown that PLT caused downregulation of the genes IL1B, CCL2, NLRP3 and NOD1, and upregulation of NFKBIA and TLR9. These findings imply that PLT has the capacity for immunomodulation in human immune cells, possibly exerting an anti-inflammatory effect.

The Effectiveness of the Polarized Low-Level Laser in the Treatment of Patients With Myofascial Trigger Points in the Trapezius Muscles

Introduction: This study assessed the effect of polarized low-level laser therapy (PLLLT) on the treatment of myofascial trigger points (MTrPs) in the trapezius muscles. Its effectiveness in pain reduction was compared to low-level laser therapy (LLLT). Methods: Sixty-four patients with MTrPs were randomly divided into 2 groups, namely PLLLT and LLLT. Each patient received treatment for a period of 2 weeks, 5 sessions a week. The intensity of laser irradiation to the skin surface was 6 J/cm² . The system exit power was 160 mw at a 755 nm wavelength. The visual analog scale (VAS) for the 1st, 5th and 10th sessions was analyzed through two-way repeated measures ANOVA. Results: Increasing the number of treatment sessions was effective in reducing pain intensity (P>0.05). The effect of LLLT on pain reduction was significantly greater than that of PLLLT (P>0.05). Referred pain (RP), the limitation of neck movement (LNM), the presence of muscular taut band (PMTB) and the sensitivity of muscular taut band (SMTB) were reduced significantly by the end of the 10th session, compared with participants' condition at the beginning of the 1st session in both groups. Conclusion: PLLLT and LLLT can effectively treat MTrPs in the trapezius muscles and they reduce RP, LNM, PMTB, and SMTB in particular. However, the effect of the LLLT was significantly greater than that of PLLLT. In accordance with the observed results, LLLT is recommended as an effective method for treating MTrPs.

Treatment of non-atopic dermatitis with polarized UV-free polychromatic light: A case report

Non-atopic dermatitis is a common inflammatory condition, which is potentially debilitating and can compromise life quality. Polarized ultraviolet-free polychromatic light is used as therapeutic option for the treatment of wound healing and dermatological conditions. It has not yet been tested in the management of non-atopic dermatitis. In this case report, we present a 67- year-old female patient who had suffered with moderate non-atopic dermatitis for the past 20 years, and had undergone multiple treatments during that time without significant improvement or relief from her symptoms. She was treated for six weeks only with daily light therapy applications (10 minutes/area). Our results showed that light therapy offered a significant reduction in erythema of the affected zones with a concomitant reduction in pruritus and dehydration of the skin, without side effects or discomfort.

Depolarizing metrics for plant samples imaging

Optical methods, as fluorescence microscopy or hyperspectral imaging, are commonly used for plants visualization and characterization. Another powerful collection of optical techniques is the so-called polarimetry, widely used to enhance image contrast in multiple applications. In the botanical applications framework, in spite of some works have already highlighted the depolarizing print that plant structures left on input polarized beams, the potential of polarimetric methods has not been properly exploited. In fact, among the few works dealing with polarization and plants, most of them study light scattered by plants using the Degree of Polarization (DoP) indicator. Other more powerful depolarization metrics are nowadays neglected. In this context, we highlight the potential of different depolarization metrics obtained using the Mueller matrix (MM) measurement: the Depolarization Index and the Indices of Polarimetric Purity. We perform a qualitative and quantitative comparison between DoP- and MM-based images by studying a particular plant, the Hedera maroccana. We show how Mueller-based metrics are generally more suitable in terms of contrast than DoP-based measurements. The potential of polarimetric measurements in the study of plants is highlighted in this work, suggesting they can be applied to the characterization of plants, plant taxonomy, water stress in plants, and other botanical studies.

Effect of orange polarized light on post burn pediatric scar: a single blind randomized clinical trial

[Purpose] This study was carried out to investigate the effect of orange filtered polarized polychromatic light on post burn pediatric scar. [Participants and Methods] Thirty children with post burn scar in wrist and hands participated in this study. They were between 3 to 7 years old, having hypertrophic burn scar ≥2 months post healing, free from concomitant skin disease and keloids. They were randomly assigned into two groups. The control group (A) (n=15) received Scar Standard Management (SSM) protocol and the study group (B) (n=15) received SSM protocol along with 15 min/area polarized light with medical range filter followed by 15 min/area orange filtered polarized light. All children received the study protocol once a day, 3 times/week for one month. Scar assessment was done before and after the study protocol by using Vancouver Scar Scale (VSS). [Results] All participated children were analyzed. Comparison of post treatment results between groups revealed significant improvement of post burn scar for both groups with significant difference in favor to the study group. [Conclusion] Ultimately it was revealed that Orange filtered polarized light has a special and beneficial effect on decreasing post burn pediatric scar.

Photobiomodulation: lasers vs. light emitting diodes?

Photobiomodulation (PBM) is a treatment method based on research findings showing that irradiation with certain wavelengths of red or near-infrared light has been shown to produce a range of physiological effects in cells, tissues, animals and humans. Scientific research into PBM was initially started in the late 1960s by utilizing the newly invented (1960) lasers, and the therapy rapidly became known as "low-level laser therapy". It was mainly used for wound healing and reduction of pain and inflammation. Despite other light sources being available during the first 40 years of PBM research, lasers remained by far the most commonly employed device, and in fact, some authors insisted that lasers were essential to the therapeutic benefit. Collimated, coherent, highly monochromatic beams with the possibility of high power densities were considered preferable. However in recent years, non-coherent light sources such as light-emitting diodes (LEDs) and broad-band lamps have become common. Advantages of LEDs include no laser safety considerations, ease of home use, ability to irradiate a large area of tissue at once, possibility of wearable devices, and much lower cost per mW. LED photobiomodulation is here to stay.

Photobiomodulation: lasers vs. light emitting diodes?

Photobiomodulation (PBM) is a treatment method based on research findings showing that irradiation with certain wavelengths of red or near-infrared light has been shown to produce a range of physiological effects in cells, tissues, animals and humans. Scientific research into PBM was initially started in the late 1960s by utilizing the newly invented (1960) lasers, and the therapy rapidly became known as "low-level laser therapy". It was mainly used for wound healing and reduction of pain and inflammation. Despite other light sources being available during the first 40 years of PBM research, lasers remained by far the most commonly employed device, and in fact, some authors insisted that lasers were essential to the therapeutic benefit. Collimated, coherent, highly monochromatic beams with the possibility of high power densities were considered preferable. However in recent years, non-coherent light sources such as light-emitting diodes (LEDs) and broad-band lamps have become common. Advantages of LEDs include no laser safety considerations, ease of home use, ability to irradiate a large area of tissue at once, possibility of wearable devices, and much lower cost per mW. LED photobiomodulation is here to stay.

Aeromonas wound infection in a healthy boy, and wound healing with polarized light

Introduction. At emergency departments, history taking is often very brief. We present a case of an Aeromonas wound infection, that illustrates the importance of careful history taking. We also report the first successful use of polarized light as additional therapy for healing of this infectious wound.

Case presentation. A healthy boy was diagnosed with a wound infection, after a fall onto rocks. At first, it remained unmentioned that there had been contact with ditchwater, so he was treated with amoxicillin-clavulanic acid. Only after the finding of an Aeromonas strain in the wound culture, and treatment with a fluoroquinolone, did he recover. Wound healing was aided with the use of polarized light, and with good effect. To our knowledge, this is the first report on the effect of polarized light on the healing of infectious wounds.

Conclusion. Careful history taking is essential for adequate empiric therapy when faced with wounds and wound infections. Aeromonas infections are associated with water exposure, and should be treated with fluoroquinolones. Polarized light seems to have a good result on healing of infectious wounds.

Effects of early versus delayed excision and grafting on the return of the burned hand function

Background:

Despite a general consensus regarding the impacts of early excision and grafting (EE and G) of burned hand on the reducing of treatment cost and hospital stay, there are some controversial issues about its effect on the outcome of hand function. This study conducted to compare the results of the EE and G and delayed skin grafting in deep hand burns regarding the hand functional outcome.

Materials and Methods:

This study was conducted from April 2012 to November 2013 in sixty patients with deep thermal burns of the dorsal hand with total body surface area (TBSA) <20% who were admitted to special burn hospital. After standard primary burn care and resuscitation, necessary procedures (EE and G or more conservative treatment) were performed based on the patients’ conditions. The patients were placed into early excision (No. =30) and delayed excision group (No. =30). Total active motion (TAM) of fingers, grip strength of the hand and the assessment of disabilities of the arm, shoulder and hand questionnaire, were measured in all patients 6 months after grafting.

Results:

The average percentage of TBSA in the EE and G group was more than the delayed excision group (17.34% ±5.12% vs. 15.64% ±5.83%), this difference was not significant (P = 0.23). After 6 months, the average of the TAM and grip strength in the EE and G group was significantly more than that of the delayed group (P < 0.0001 and P = 0.019).

Conclusion:

The present study showed that EE and G with proper physical therapy and rehabilitation management provides a higher functional outcome in dorsal deep burned hand.

Phototherapy for treating pressure ulcers

BACKGROUND

A pressure ulcer is defined as "an area of localized injury to the skin and/or underlying tissue, usually over a bony prominence, as a result of pressure, or pressure in combination with shear". The use of phototherapy - that is, light (or laser) used as an adjuvant, non-surgical intervention, with the aim of having a therapeutic effect on healing - has increased recently.

OBJECTIVES

To determine the effects of phototherapy on the healing of pressure ulcers.

SEARCH METHODS

In January 2014, we searched the Cochrane Wounds Group Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid EMBASE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); and EBSCO CINAHL. We did not restrict the search by language or publication date.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the effects of phototherapy (in addition to standard treatment) with sham phototherapy (in addition to standard treatment), another type of phototherapy (in addition to standard treatment) or standard or conventional treatment alone.

DATA COLLECTION AND ANALYSIS

Two review authors assessed studies for relevance and design according to the selection criteria, extracted data and evaluated study quality. The authors made attempts to obtain missing data by contacting study authors. Disagreement was resolved by consensus and discussion with a third review author.

MAIN RESULTS

We identified seven RCTs involving 403 participants. All the trials were at unclear risk of bias. Trials compared the use of phototherapy with standard care only (six trials) or sham phototherapy (one trial). Only one of the trials included a third arm in which another type of phototherapy was applied. Overall, there was insufficient evidence to determine the relative effects of phototherapy for healing pressure ulcers. Time to complete healing was reported in three studies. Two studies showed the ultraviolet (UV) treated group had a shorter mean time to complete healing than the control group (mean difference -2.13 weeks (95% CI -3.53 to -0.72, P value 0.003)). One study reported that the laser group had a longer mean time to complete healing than the control group (mean difference 5.77 weeks; 95% CI -0.25 to 11.79). However, this result should be interpreted with caution, as these were small studies and the findings may have been due to chance. Three studies reported proportions of ulcers healed with a variety of results. One study reported a different outcome measure, and the other two studies had different treatment durations. These variations did not allow us to pool the studies and draw any conclusions as to whether phototherapy is effective or not. Adverse effects were reported in only two studies that compared phototherapy with control; the risk ratio for adverse events was imprecise. One study reported risk ratio (RR) 0.72 (95%CI 0.18 to 2.80). However, another study reported RR 0.89 (95% CI: 0.71 to 1.12) based on the number of events in each group, rather than the number of people with events. Among five studies reporting the rate of change in ulcer area, three studies found no statistically significant difference between the two groups. Pooling was not undertaken because of differences in outcome measures reported. The results were based on data from trials with unclear risk of bias for which generation of the randomisation sequence, concealment allocation and blinding of outcome assessors were unclear. No studies reported on quality of life, length of hospital stay, pain or cost.

AUTHORS' CONCLUSIONS

We are very uncertain as to the effects of phototherapy in treating pressure ulcers. The quality of evidence is very low due to the unclear risk of bias and small number of trials available for analysis. The possibility of benefit or harm of this treatment cannot be ruled out. Further research is recommended.

Which medical devices and/or local drug should be curatively used, as of 2012, for PU patients? How can granulation and epidermidalization be promoted? Developing French guidelines for clinical practice

INTRODUCTION

Management of a patient with pressure ulcer sore(s) must associate local and general treatment.

OBJECTIVES

To determine which medical devices other than supports and which treatments may be used for pressure sore healing (granulation tissue and epithelization/epidermidalization) as of 2012.

METHODS

Systematic review of the literature querying the databases: PASCAL Biomed, PubMed, and Cochrane library from 2000 through 2010.

RESULTS

Data in the literature on granulation tissue and epithelisation/epidermidalization in pressure sore healing are poor. The level of evidence regarding the relative effectiveness of one modern dressing compared to another has remained low. However, the study data on the interest of hydrocolloid dressing compared with impregnated gases are more significant.

DISCUSSION

Studies with heterogeneous results and populations have shown low power. Meta-analyses are difficult due to the wide range of therapeutic aims. Further clinical studies with adequate methodology are needed prior to elaboration of more specific recommendations.

CONCLUSION

The use of hydrocolloid dressing may be recommended to improve granulation tissue development and epithelization/epidermidalization in pressure sore (Level B).

Evaluation of the effects of polarized light (λ400-200 nm) on the healing of third-degree burns in induced diabetic and nondiabetic rats

OBJECTIVE

The study evaluated, by light microscopy, the repair process on third-degree burns on diabetic and nondiabetic rats, illuminated or not, with a polarized light (PL) source.

BACKGROUND DATA

Burns are severe injuries that result in the loss of fluid and destruction of tissue, infection, and shock that may result in death. Diabetes mellitus is a public health problem that, being uncontrolled, causes severe disturbance to the body metabolism, including on wound healing. PL sources have been shown to be effective in improving healing in many situations.

MATERIALS AND METHODS

Ninety male Wistar rats were divided into two groups (n=45): nondiabetic and diabetic. In one of the groups, diabetes mellitus was induced by streptozotocin. A third-degree burn, measuring 1.5×1.5 cm(2), was created in the dorsum of each animal. Phototherapy (λ400-2000 nm, 10.2 or 20.4 J/cm(2)) started immediately after burning and was repeated daily until animal death (7, 14, and 21 days). Specimens were taken, processed, and stained with H&E and Sirius red and immunomarked with cytokeratin (CK) AE1/AE3. Descriptive analysis was performed by light microscopy.

RESULTS

Animals subjected to phototherapy showed an acceleration of the repair, the dose of 10.2 J/cm(2) being the one that caused best results, including higher deposition of collagen, quicker inflammatory reaction, and improved revascularization.

CONCLUSIONS

Our results suggest that the use of PL (10.2 J/cm(2)) improves the healing of third-degree burns on both diabetic and nondiabetic animals.

Effects of a polarized light source (400-2000 nm) on Hep.2 and L929 cell lines: a spectroscopic in vitro study

OBJECTIVE

The aim of this study was to evaluate the effects on Hep.2 cells originating from laryngeal carcinomas, and L929 cells originating from a fibroblast line, subjected to polarized light at a wavelength of 400-2000 nm.

BACKGROUND DATA

Recently there has been increased interest in the propagation of polarized light in randomly scattering media such as biological tissues, because of its potential applications in medicine.

MATERIALS AND METHODS

Irradiation was performed at two time points: T0 (24 h after cell culture) and T48 (48 h after the first irradiation). Cellular viability was assessed using an MTT assay at the following times: T0 (first irradiation), T6 (6 h after the first irradiation), T12 (12 h after the first irradiation), T24 (24 h after the first irradiation), T48 (48 h after the first irradiation), and T72 (72 h after the first irradiation). The results were analyzed using Graphpad Prism software.

RESULTS

The results showed that time influenced the cellular viability of L929 cells of both control (p = 0.0014) and illuminated cultures (p = 0.0035). Significant differences between control cells (p = 0.0001) and illuminated Hep.2 cells (p = 0.0001) were observed. There was a significant difference between the proliferation of the two types of cells illuminated compared to their controls: Hep.2 (p = 0.0001) and L929 (p = 0.0002).

CONCLUSION

The use of polarized light on Hep.2 and L929 cells resulted in photobiological effects that need further investigation, as this is the first study using this methodology.

Effect of visible and infrared polarized light on the healing process of full-thickness skin wounds: an experimental study

OBJECTIVE AND BACKGROUND DATA

Polarized light has already been experimentally and clinically used in an effort to promote wound healing, but the findings have been equivocal. The aim of this study was to evaluate the effect of visible and infrared polarized light of a specific range of wavelength (580-3400 nm) on the secondary healing of full-thickness skin wounds in rats.

MATERIALS AND METHODS

Forty male Wistar rats were used, divided in two groups of 20 animals each. A standardized open full-thickness skin wound was created on the back of each animal. In the first group the rats were exposed to polarized light (40 mW/cm(2) and 2.4 J/cm(2)) for 7 min on a daily basis (total daily dose = 16.8 J/cm(2)), while the second group acted as controls. Clinical and histological evaluation of wound healing were performed on days 5, 10, 15, and 20 post-wound. The size of the wounds was measured with the use of planimetry, whereas epithelialization, inflammatory response, neovascularization, and collagen formation were histologically assessed.

RESULTS

According to our findings, the group exposed to light therapy showed statistically significantly faster epithelialization seen on days 10 and 15 post-wound compared to controls, as well as better quality of the healing process (although not statistically significantly) at all time points.

CONCLUSION

In conclusion, this specific fraction of polarized light seems to have beneficial effects on wound healing, leading to faster epithelialization and qualitatively better wound healing.

Basic fibroblast growth factor accelerates and improves second-degree burn wound healing

Second-degree burns are sometimes a concern for shortening patient suffering time as well as the therapeutic choice. Thus, adult second-degree burn patients (average 57.8 +/- 13.9 years old), mainly with deep dermal burns, were included. Patients receiving topical basic fibroblast growth factor (bFGF) or no bFGF were compared for clinical scar extent, passive scar hardness and elasticity using a Cutometer, direct scar hardness using a durometer, and moisture analysis of the stratum corneum at 1 year after complete wound healing. There was significantly faster wound healing with bFGF, as early as 2.2 +/- 0.9 days from the burn injury, compared with non-bFGF use (12.0 +/- 2.2 vs. 15.0 +/- 2.7 days, p<0.01). Clinical evaluation of Vancouver scale scores showed significant differences between bFGF-treated and non-bFGF-treated scars (p<0.01). Both maximal scar extension and the ratio of scar retraction to maximal scar extension, elasticity, by Cutometer were significantly greater in bFGF-treated scars than non-bFGF-treated scars (0.23 +/- 0.10 vs. 0.14 +/- 0.06 mm, 0.59 +/- 0.20 vs. 0.49 +/- 0.15 mm: scar extension, scar elasticity, bFGF vs. non-bFGF, p<0.01). The durometer reading was significantly lower in bFGF-treated scars than in non-bFGF-treated scars (16.2 +/- 3.8 vs. 29.3 +/- 5.1, p<0.01). Transepidermal water loss, water content, and corneal thickness were significantly less in bFGF-treated than in non-bFGF-treated scars (p<0.01).

The effects of daily irradiation with polychromatic visible polarized light on human lymphocyte populations

OBJECTIVE

The goal of this randomized, placebo controlled, double-blind study was to investigate the effects of transcutaneous irradiation with polychromatic visible polarized light (540-780 nm; 68% polarization; power density 3.0 E-10 W/cm(2)) on a subset population of human lymphocytes using flow cytometry.

BACKGROUND DATA

The biomodulation and therapeutic effects of visible light of different wavelengths are well known, but the immunological effects of polychromatic visible polarized light have not been investigated sufficiently.

METHODS

Before and after 28 consecutive days of irradiation, blood samples were collected from the subjects and the population count of the lymphocyte subset was measured.

RESULTS

The absolute count of total lymphocytes, CD3(+) lymphocytes, and CD3(+)CD4(+) lymphocytes increased by 7% (p = 0.023), 9% (p = 0.058), and 13% (p = 0.021), respectively. Yet the absolute count of WBCs, CD3(+)CD8(+), CD19(+), and CD16(+)56(+) lymphocytes did not change significantly.

CONCLUSION

The application of polychromatic visible polarized light with the aforementioned features increases the CD3(+)CD4(+) lymphocyte population. It is suggested that this regimen may be useful for the promotion of natural defenses in cell-mediated immunity.

The effects of polarized light therapy in pressure ulcer healing

Background/Aim. Neglecting polarized light as an adjuvant therapy for pressure ulcers and methodology distinctions in the trials engaging polarized light are the reasons for many dilemmas and contradictions. The aim of this study was to establish the effects of polarized light therapy in pressure ulcer healing. Methods. This prospective randomized single-blind study involved 40 patients with stage I-III of pressure ulcer. The patients in the experimental group (E) were subjected, besides polarized light therapy, to standard wound cleaning and dressing. Standard wound cleaning and dressing were the only treatment used in the control group (C). A polarized light source was a Bioptron lamp. Polarized light therapy was applied for six min daily, five times a week, four weeks. The Pressure Ulcer Scale for Healing (PUSH) was used in the assessment of outcome. Statistic analysis included Mann Whitney Test, Fisher Exact Test, Wilcoxon Signed Rank test. Results. There were significant differences between the groups at the end of the treatment regarding the surface of pressure ulcer (E: 10.80?19.18; C: 22,97?25,47; p = 0.0005), rank of pressure ulcer (E: 5.90?2.48; C: 8.6?1.05; p = 0.0005) and total PUSH score (E: 7.35?3.17; C: 11.85?2.35; p = 0,0003). The patients in the experimental group had significantly better values of the parameters monitored than the patients in the control group. Conclusion. After a four-week polarized light therapy 20 patients with stage I-III ulcer had significant improvement in pressure ulcer healing, so it could be useful to apply polarized light in the treatment of pressure ulcers.

Effects of a single near-infrared laser treatment on cutaneous wound healing: Biometrical and histological study in rats

BACKGROUND

Low intensity laser therapy has been recommended to support the cutaneous repair; however, so far studies do not have evaluated the tissue response following a single laser treatment. This study investigated the effect of a single laser irradiation on the healing of full-thickness skin lesions in rats.

METHODS

Forty-eight male rats were randomly divided into three groups. One surgical lesion was created on the back of rats using a punch of 8mm in diameter. One group was not submitted to any treatment after surgery and it was used as control. Two energy doses from an 830-nm near-infrared diode laser were used immediately post-wounding: 1.3 J cm(-2) and 3 J cm(-2). The laser intensity 53 m W cm(-2) was kept for both groups. Biometrical and histological analyses were accomplished at days 3, 7 and 14 post-wounding.

RESULTS

Irradiated lesions presented a more advanced healing process than control group. The dose of 1.3 J cm(-2) leaded to better results. Lesions of the group irradiated with 1.3 J cm(-2) presented faster lesion contraction showing quicker re-epithelization and reformed connective tissue with more organized collagen fibers.

CONCLUSIONS

Low-intensity laser therapy may accelerate cutaneous wound healing in a rat model even if a single laser treatment is performed. This finding might broaden current treatment regimens.

The efficacy of linear polarized polychromatic light on burn wound healing: an experimental study on rats

We aimed to investigate the questionable effect of linear polarized polychromatic light on burn wound healing in rats. Two deep second-degree burn wounds on the backside of each of 21 Sprague-Dawley rats were created with a standard burning procedure by applying a heated plaque. Burned regions located right dorsolaterally and classified as group I lesions were treated with linear polarized polychromatic light + open dressing + antibacterial pomade, whereas group II lesions were located left dorsolaterally and treated with only open dressing + antibacterial pomade. Macroscopic evaluation was performed for determination of the completed wound closure rate, measurement of burn wound area, and investigation of macroscopic edema, hyperemia, and epithelialization. Histopathological evaluation included monitoring of epithelialization, vascularization, origination of granulation tissue, inflammatory cell response, and total histopathological score on days 7, 14, and 21 after burn creation. Macroscopic evaluation revealed more obvious epithelialization in group I lesions between days 6 and 15. The number of completely closed wounds was higher in group I than in group II on days 16 and 21. The average area of burn wounds was lower from day 5, hyperemia was less on days 2 to 17, and edema was less from day 4 to day 13 in group I lesions. Histopathological evaluation revealed a higher rate of epithelialization on day 7 and higher vascularization occurrence on day 21 in group I lesions. Linear polarized polychromatic light seems to be effective in the treatment of burn wounds and in the promotion of healing. This may be related to linear polarized polychromatic light stimulation of epithelialization and vascularization.

Use of polarised light as a method of pressure ulcer prevention in an adult intensive care unit

OBJECTIVE

This single-centred randomised pilot study aimed to examine whether the wound-healing properties of polarised light are effective in preventing grade II or above pressure ulcers in patients admitted to an adult intensive care unit.

METHOD

Standard pressure ulcer prevention techniques were applied in both research groups. Patients allocated to the test group received supplementary treatment with polarised light once daily for 10 minutes (sacral area and both heels) starting on the first day after admission. The control group received no polarised light.

RESULTS

A control group of 13 patients and an intervention group of 10 patients were included in the study between 1 March and 1 May 2006. There was no statistically significant difference between the groups for composition, standard pressure ulcer prevention or pressure ulcer risk. Observations revealed a statistically significant difference (p = 0.019) between the groups when comparing development of grade II or above sacral or heel pressure ulcers.

CONCLUSION

Patients treated with polarised light developed significantly (p = 0.019) fewer grade II or above sacral or heel pressure ulcers when compared with a control group receiving no polarised light. Further research is required.

Biomodulative Effects of Polarized Light on the Healing of Cutaneous Wounds on Nourished and Undernourished Wistar Rats

OBJECTIVE

This study aimed to evaluate, by light microcopy, the differences in healing process of cutaneous wounds on nourished or undernourished rats following illumination by polarized light (lambda400-2000 nm) with 20 or 40 J/cm(2).

BACKGROUND DATA

There are some reports in the literature on different effects of polarized light on wound healing. Amongst the factors that interfere with wound healing one is the nutritional status of the subject.

METHODS

Thirty nourished or undernourished Wistar rats had one standardized surgical wound created on the dorsum and were divided into six groups: group 1, control (standard diet); group 2, control (Northeastern Brazilian Basic Diet [DBR]); group 3, standard diet + polarized light (20 J/cm(2)); group 4, standard diet + polarized light (40 J/cm(2)); group 5, DBR + polarized light (20 J/cm(2)); group 6, DBR + polarized light (40 J/cm(2)). The first application of treatment was carried out immediately after wounding and repeated every 24 h during 7 days. The animals were sacrificed, and specimens were taken and routinely processed to wax, cut, and stain with hematoxylin and eosin (H&E) and Sirius Red. These were then analyzed under light microscopy. The analysis included re-epitheliialization, inflammatory infiltrate, and fibroblastic proliferation. Sirius Red-stained slides were used to perform descriptive analysis of collagen.

RESULTS

The analysis of the results showed better results in these groups illuminated with 20 J/cm(2).

CONCLUSION

It is concluded that nutritional status influenced the progression of the healing process as well as the quality of the healed tissue, and that the use of polarized light resulted in a positive biomodulatory effect.

Outcome and changes over time in survival following severe burns from 1985 to 2004

OBJECTIVE

To investigate outcome in severely burned patients over a 20-year period and to evaluate survival over time.

DESIGN AND SETTING

Historical cohort in a six-bed burn unit of a 1060-bed university hospital.

PATIENTS

1385 patients admitted to the burn unit over a 20-year period.

MEASUREMENTS AND RESULTS

Outcome was evaluated in relation to the presence of three major risk factors for death: age 60 years or over, total burned surface area 40% or more, and the presence of inhalation injury. Overall mortality was 7.1%. When zero, one, two, or three risk factors were present, mortality was respectively 0.5%, 9.9%, 48.0%, and 90.5%. Over the study period the average proportional total burned surface area decreased as did mortality. The survival benefit was significant among patient groups with one or two risk factors present. Multivariate regression analysis adjusting for risk factors for death confirmed that survival improved over time (odds ratio 0.73 per 5-year period).

CONCLUSIONS

Global mortality following burns is low, and nearly all patients who die had at least one risk factor present. In the presence of three risk factors the prognosis following burns is particularly compromised. Taking into account that our patients over the past 20 years have been progressively less extensively burned and hence have a lesser at risk for death, survival following severe burns has continued to improve.

Polarized Light (400–2000 nm) and Non-ablative Laser (685 nm): A Description of the Wound Healing Process Using Immunohistochemical Analysis

OBJECTIVE

This study aimed to describe, through morphologic and cytochemical analysis, the healing process of wounds submitted (or not) to laser therapy (lambda685 nm) or polarized light (lambda400-2000 nm).

BACKGROUND DATA

There are many reports on different effects of several types of phototherapies on the treatment of distinct conditions, amongst them, on wound healing. Laser therapy and the use of polarized light are still controversial despite successive reports on their positive effects on several biological processes.

METHODS

Thirty male Wistar rats, approximately 4 months old, were used, and standardized excisional wounds were created on their dorsum. The wounds were irradiated in four equidistant points with laser light or illuminated with polarized light, both with doses of 20 or 40 J/cm2. Group 1 acted as untreated controls. Animals were irradiated every 48 h during 7 days, starting immediately after surgery, and were humanely killed on the 8th post-operative day. Specimens were taken and routinely processed and stained with H&E, and for descriptive analysis of myofibroblasts and collagen fibers, the specimens were imunnomarked by smooth muscle alpha-actin and picrosirius stain.

RESULTS

Control specimens showed the presence of ulceration, hyperemia, discrete edema, intense, and diffuse inflammation, collagen deposition was irregular, and myofibroblasts were seen parallel to the wound margins. Wounds treated by laser therapy with a dose of 20 J/cm2 showed mild hyperemia, inflammation varied from moderate to intense, the number of fibroblasts was large, and the distribution of collagen fibers was more regular. Increasing the dose to 40 J/cm2 evidenced exuberant neovascularization, severe hyperemia, moderate to severe inflammation, large collagen deposition, and fewer myofibroblasts. On subjects illuminated with polarized light with a dose of 20 J/cm2, mild to moderate hyperemia was detectable, and collagen matrix was expressive and unevenly distributed; a larger number of myofibroblasts was present and no re-epithelialization was seen. Increasing the dose resulted in mild to moderate hyperemia, no re-epithelialization was seen, edema was discrete, and inflammation was moderate.

CONCLUSION

The use of 685-nm laser light or polarized light with a dose of 20 J/cm2 resulted in increased collagen deposition and better organization on healing wounds, and the number of myofibroblast was increased when polarized light is used.

The use of polarized light in aesthetic surgery

This article presents a clinical investigation of polarized light therapy after aesthetic surgery procedures. The study included patients who the authors underwent face-lifts, blepharoplasties, and various facial ancillary procedures, at center during the past 2 1/2 years. One side of the surgically treated area was managed with polarized light, whereas the other side served as a control. The results were compared using clinical examination only including signs of recovery such as resolution of swelling and bruises. The results in most cases showed a significant difference between the treated and untreated sides.