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Photodynamic therapy alone or in combination to counteract bacterial infections

INTRODUCTION

Antibacterial photodynamic therapy presents a promising alternative to antibiotics, with potential against multidrug-resistant bacteria, offering broad-spectrum action, reduced resistance risk, and improved tissue selectivity.

AREAS COVERED

This manuscript reviews patent literature in the field of antibacterial photodynamic therapy through the period of 2019-2023. All data are from the US and European patent databases and SciFinder.

EXPERT OPINION

Antibacterial photodynamic therapy (PDT) is an appealing approach for treating bacterial infections, especially biofilm-related ones, by releasing reactive oxygen species (ROS) upon light activation. Its success is driven by a growing variety of photosensitizers (PSs) with tailored properties, like water solubility, controllable surface charge, and ROS generation efficiency. Among them, Aggregation Induced Emission (AIE)-type PSs are promising, demonstrating enhanced efficacy when aggregated in biological environments. However, the penetration of pristine PSs into bacterial biofilms within deep tissues or complex anatomical regions is limited, reducing their antibacterial effectiveness. To address this, nanotechnology has been integrated into antibacterial PDT to synthesize various nano-PSs. This adaptability allows seamless integration with other antimicrobial treatments, offering a comprehensive approach to combat localized infections, especially in dentistry and dermatology. By combining PSs with complementary therapies, antibacterial PDT offers a multifaceted strategy for effective microbial control and management.

Unlocking the Power of Light on the Skin: A Comprehensive Review on Photobiomodulation

Photobiomodulation (PBM) is a procedure that uses light to modulate cellular functions and biological processes. Over the past decades, PBM has gained considerable attention for its potential in various medical applications due to its non-invasive nature and minimal side effects. We conducted a narrative review including articles about photobiomodulation, LED light therapy or low-level laser therapy and their applications on dermatology published over the last 6 years, encompassing research studies, clinical trials, and technological developments. This review highlights the mechanisms of action underlying PBM, including the interaction with cellular chromophores and the activation of intracellular signaling pathways. The evidence from clinical trials and experimental studies to evaluate the efficacy of PBM in clinical practice is summarized with a special emphasis on dermatology. Furthermore, advancements in PBM technology, such as novel light sources and treatment protocols, are discussed in the context of optimizing therapeutic outcomes and improving patient care. This narrative review underscores the promising role of PBM as a non-invasive therapeutic approach with broad clinical applicability. Despite the need for further research to develop standard protocols, PBM holds great potential for addressing a wide range of medical conditions and enhancing patient outcomes in modern healthcare practice.

Mitochondrial dysfunction and neurological disorders: A narrative review and treatment overview

Mitochondria play a vital role in the nervous system, as they are responsible for generating energy in the form of ATP and regulating cellular processes such as calcium (Ca2+) signaling and apoptosis. However, mitochondrial dysfunction can lead to oxidative stress (OS), inflammation, and cell death, which have been implicated in the pathogenesis of various neurological disorders. In this article, we review the main functions of mitochondria in the nervous system and explore the mechanisms related to mitochondrial dysfunction. We discuss the role of mitochondrial dysfunction in the development and progression of some neurological disorders including Parkinson's disease (PD), multiple sclerosis (MS), Alzheimer's disease (AD), depression, and epilepsy. Finally, we provide an overview of various current treatment strategies that target mitochondrial dysfunction, including pharmacological treatments, phototherapy, gene therapy, and mitotherapy. This review emphasizes the importance of understanding the role of mitochondria in the nervous system and highlights the potential for mitochondrial-targeted therapies in the treatment of neurological disorders. Furthermore, it highlights some limitations and challenges encountered by the current therapeutic strategies and puts them in future perspective.

Photodynamic therapy in pediatric age: Current applications and future trends

Photodynamic therapy (PDT) is a photochemotherapy based on local application of a photosensitive compound and subsequent exposure to a light source of adequate wavelength. It is a non-invasive therapeutic procedure widely used in oncodermatology for treatment of numerous skin cancers, but in the last years its use has been gradually extended to an increasing list of skin diseases of both infectious and inflammatory nature. Although PDT is proven as a safe and effective therapeutic option in adults, its use is not well standardized in the pediatric population. In this review, we will focus on clinical applications, mechanisms of action, protocols, and adverse events in children and adolescents. Most of pediatric experiences concerned treatment of skin cancers in Gorlin syndrome and xeroderma pigmentosum, acne vulgaris, and viral warts, but other applications emerged, such as cutaneous lymphoma and pseudo-lymphomas, necrobiosis lipoidica, hidradenitis suppurativa, dissecting cellulitis, leishmaniasis, angiofibromas, verrucous epidermal nevus, and linear porokeratosis. In these pediatric diseases, PDT appeared as an effective therapeutic alternative. The results on vitiligo were limited and not fully encouraging. Although highly versatile, PDT is not a therapy for all skin diseases, and a deeper knowledge of its mechanisms of action is required to better define its spectrum of action and safety in pediatric patients.

The Use of Lasers and Light Devices in Acne Management: An Update

Acne vulgaris is a disease of the pilosebaceous unit and the most common inflammatory dermatosis worldwide. It is also associated with significant economic burden. Limitations of conventional topical and systemic treatments include long treatment course, intolerable adverse effects, antibiotic resistance, and patient compliance. Therefore, laser and light-based interventions present as alternative options over the past decade and have been used in combination with conventional pharmacological therapies and other physical modalities. An updated overview on the use of lasers and light-based devices in acne management is presented to help clinicians understand the safety and efficacy of these treatment options. The effectiveness of neodymium:yttrium aluminum garnet (Nd:YAG) for treating acne is supported by more high-level studies compared with other laser devices. There is limited evidence to support the use of CO₂ lasers, potassium titanyl phosphate lasers, and 1565-nm non-ablative fractional lasers for treating acne. Among light devices, photodynamic therapy is the most studied, showing higher efficacies than some of the conventional topical and oral acne therapies. Intense-pulsed light and blue light therapies also show favorable outcomes. A limitation is that most studies are non-randomized and lack a control group, and report on a variety of device settings, treatment regimens, and outcome measures, making it challenging to summarize and generalize findings. Although the use of laser and light devices to treat acne is promising, further work with randomized controlled study designs and larger sample sizes will provide improved guidance on the application of these modalities.

Application of red light therapy for moderate-to-severe acne vulgaris: A systematic review and meta-analysis

BACKGROUND

Photodynamic therapy had made great progress in the treatment of acne vulgaris. However, there is no meta-analysis on the effectiveness and safety of red light therapy for acne vulgaris.

OBJECTIVE

To assess the efficiency and safety of red light therapy for acne vulgaris.

METHODS

PubMed, Cochrane Library, EMBASE, and Web of Science were retrieved to identify related studies. The outcomes were expressed as improvement in the average percentages of inflammatory acne lesions (MPRI) and non-inflammatory acne lesions (NMPRI), as well as the improvement of acne lesions respectively after treatment.

RESULTS

13 randomized controlled trials (RCTs) consisting of 422 participants were included. There was no significant difference in the average number of non-inflammatory lesions (weighted mean difference (WMD = -0.527; 95% CI,-3.055~2.001; p = 0.683). Moreover, there was no statistically significant difference in the average number of inflammatory lesions (WMD =0.701; 95% CI, -0.809~2.212; p =0.363). In the subgroup analysis of the outcome changes in comedones, pustules, papules, and total lesions, it was found that red light therapy elicited no significant superiority compared with other conventional treatment methods (WMD = -1.125; 95% CI, -3.122~0.873; p = 0.270). Adverse events of the red light group were generally mild or even completely non-existent.

CONCLUSION

There was no statistically significant difference between red light therapy and traditional therapies in terms of efficacy. However, due to the heterogeneity of the researches and the lack of large sample size, the result of this study needs to be interpreted with caution.

Fundamentals of Optical Imaging

Optical imaging, which possesses noninvasive and high-resolution features for biomedical imaging, has been used to study various biological samples, from in vitro cells, ex vivo tissue, to in vivo imaging of living organism. Furthermore, optical imaging also covers a very wide scope of spatial scale, from submicron sized organelles to macro-scale live biological samples, enabling it a powerful tool for biomedical studies. Before introducing these superior optical imaging methods to researchers, first of all, it is necessary to present the basic concept of light-matter interactions such as absorption, scattering, and fluorescence, which can be used as the imaging contrast and also affect the imaging quality. And then the working mechanism of various imaging modalities including fluorescence microscopy, confocal microscopy, multiphoton microscopy, super-resolution microscopy, optical coherence tomography (OCT), diffuse optical tomography (DOT), etc. will be presented. Meanwhile, the main features and typical bioimaging applications of these optical imaging technologies are discussed. Finally, the perspective of future optical imaging methods is presented. The aim of this chapter is to introduce the background and principle of optical imaging for grasping the mechanism of advanced optical imaging modalities introduced in the following chapters.

Narrow Band Ultraviolet B Versus Red Light-Emitting Diodes in the Treatment of Facial Acne Vulgaris: A Randomized Controlled Trial

Background: One of the most common dermatological conditions affecting most teenagers is acne. Phototherapy was described as a therapeutic modality with low-side effects of acne vulgaris (AV). Hence, we examined the effects of narrow band ultraviolet B (NBUVB) versus red light-emitting diodes (LEDs) on facial AV. Methods: Forty-five subjects suffering from facial AV mild to a moderate degree were randomly assigned into three groups, 15 subjects within every group. Group A was equipped to NBUVB with 311-313 nm and an initial dose of 250 mJ/cm², thrice a week for 8 weeks, Group B was equipped red LED with wavelengths 633 ± 6 nm and power density of 80 mW/cm², thrice a week for 8 weeks, whereas group C had received the only erythromycin as a control group. Outcome measures included measurement of acne lesion count and degree of severity. Measures at three-time intervals were assessed: baseline, 4 weeks (post I), and 8 weeks (post II). Results: Acne numeral findings revealed a significant variance among groups A, B, and C in favor of group A (p < 0.001). Notable improvements were observed across all three groups (p < 0.001). The degree of adjustment effects indicated a greater increase in group A in comparison with group B (p < 0.01), whereas no statistical variance was detected between group B and group C (p > 0.05). Conclusions: Both NBUVB and red LED were effective in acne treatment; NBUVB, however, revealed a highly efficient treatment than red LED in decreasing the acne lesions count and the improved degree of AV severity as measured by the global investigator's assessment scale. Clinical Trial Registration No. NCT04254601.

Treatment of cutaneous basal cell carcinoma with combined laser extirpation and methyl aminolevulinic acid: five-year success rates

INTRODUCTION

Basal cell carcinoma is the most common cancer. Excisional surgery is associated with a high clearance rate, at the expense of significant functional and aesthetic morbidity, especially within the T-zone or for extensive lesions. We report five-year follow-up outcomes for carbon dioxide laser extirpation of cutaneous basal cell carcinoma, assisted by immediate methyl aminolevulinate photodynamic therapy and cost-benefit considerations.

MATERIALS AND METHODS

Retrospective cohort database analysis of adult patients with biopsy-proven primary cutaneous basal cell carcinoma, completing five years of follow-up. Direct per-lesion cost was compared with conventional wide local excision. Patients with morphoeic basal cell carcinoma were excluded.

RESULTS

Treated lesions were up to 1% total body surface area and up to 3.8mm (1.38 ± 0.695cm, mean ± standard deviation) in biopsy-proven depth. At the five-year follow-up mark, 93.6% of treated areas remained free of recurrence. Nodular basal cell carcinoma was the most common subtype (41.5%). A mean tumour depth greater than 2 ± 0.872mm was significantly associated with recurrence (Mann-Whitney, p = 0.0487). For a service delivered through the NHS at 2015 prices, we report a 43% saving, equating to a saving of £235 per basal cell carcinoma or a national annualised saving of £70 million by 2025 for the NHS.

CONCLUSION

Our results suggest that CO2-assisted photodynamic therapy is non-inferior to excision but may offer better functional and cosmetic preservation at a fraction of the direct like for like cost of operative surgery. Investigation of this method by randomised controlled methodology is warranted.

Photodynamic Therapy for Benign Cutaneous Neurofibromas Using Aminolevulinic Acid Topical Application and 633 nm Red Light Illumination

Background: Neurofibromatosis type 1 (NF1) has no current effective treatments beyond surgery. Topical photodynamic therapy (PDT) has the potential to provide a less invasive treatment modality.

Objective: Based on murine data, we hypothesized PDT could be used for the treatment of cutaneous neurofibromas (cNF).

Methods and results: We conducted a phase I trial to examine absorption and conversion of topical aminolevulinic acid (ALA) in cNF and determine safety in a dose escalation study. ALA or control vehicle was applied to neurofibromas through microneedle-assisted delivery (n = 4) and excised specimens were examined 24 h later for protoporphyrin IX fluorescence. Fluorescence was detected in the tumors at 304 ± 94 U/μm², while adjacent paralesional normal skin and vehicle-treated tumors showed no fluorescence (p < 0.0001). Subsequently, neurofibromas (n = 27) were treated with ALA and irradiated with 633 nm red light 18 h later, at escalating dosages of 50 and 100 mJ/cm². Maximum tolerable dose was established at 100 mJ/cm². Light microscopy study of tumors biopsied 48 h after PDT (ALA n = 14 and vehicle n = 4) showed mixed inflammatory infiltrate in the ALA, but not in the vehicle-treated tumors or perilesional normal skin. TUNEL evaluation showed 42.5 ± 19.9 apoptotic cells per visual field for ALA-treated and 1.1 ± 1.4 for vehicle-treated tumors (p = 0.002).

Conclusions: In the first reported clinical trial of PDT for NF1, PDT targeted neurofibromas specifically, and may offer a normal tissue-sparing treatment modality in the future.

This study is registered at Clintrials.gov (NCT01682811).

Antibiotic Resistance in Acne: Mechanisms, Complications and Management

Antibiotic resistance in acne was first observed in the 1970s, and since the 1980s has become a major concern in dermatologic daily practice. The mechanisms for this type of resistance include biofilm formation that promotes virulence and the transmission of resistant bacterial strains. Genetic mutations with modification of ribosomal RNA, alteration in efflux pumps, and enzymatic inactivation are able to create resistance to tetracyclines and macrolides. The state of art in acne treatment is no longer to use antimicrobials as monotherapy. There should be a time limit for its use plus the employment of non-antibiotic maintenance. Earlier initiation of oral isotretinoin therapy should be considered in patients with insufficient response to antimicrobials, severe acne, or a history of repeated antimicrobial use. A better understanding of acne pathogenesis, the subtypes of Propionibacterium (also known as Cutibacterium) acnes, homeostasis of the skin microbiota, and the mechanisms of antibiotic resistance would be useful in the selection of narrow-spectrum or species-specific antimicrobials, as well as the non-antimicrobial, anti-inflammatory treatment of acne. A number of novel treatments awaiting clinical proof may include the use of bacteriophages, natural or synthetic antimicrobial peptides, probiotics, and biofilm-targeting agents, as well as the reassessment of phototherapy.

Identifying and appraising patient-reported outcome measures on treatment satisfaction in acne: a systematic review

BACKGROUND

After dermatitis, acne is the next skin disease to contribute most to the burden of skin diseases worldwide. Recently, seven core outcome domains have been identified, which together form an Acne Core Outcome Set (ACORN). One of these was satisfaction with acne treatment.

OBJECTIVES

To identify studies that described the development of patient-reported outcome measures (PROMS), evaluated one or more measurement properties of a PROM, or evaluated the interpretability of a PROM in patients with acne regarding treatment satisfaction.

METHODS

The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) search strategy for identifying PROMS on acne treatment satisfaction was used. We searched PubMed, MEDLINE, Embase, LILACS, Web of Science, Cochrane Library, Emcare, PsycINFO and Academic Search premier (June 2020). Study selection, data extraction and assessment of methodological quality according to COSMIN guidance were carried out independently by two authors.

RESULTS

Only one study could be included, describing the development of a treatment satisfaction measure in patients with acne. The development was assessed as inadequate and data on measurement properties were lacking. Additionally, we found 188 studies reporting treatment satisfaction solely as an outcome, using a wide variety of methods, none of them standardized or validated.

CONCLUSIONS

We could not find a PROM on treatment satisfaction to recommend for a core outcome set in acne. There is an unmet need for a PROM on treatment satisfaction in acne that is robustly developed, designed and validated.

Recent Progress of Fiber Shaped Lighting Devices for Smart Display Applications-A Fibertronic Perspective

Advances in material science and nanotechnology have fostered the miniaturization of devices. Over the past two decades, the form-factor of these devices has evolved from 3D rigid, volumetric devices through 2D film-based flexible electronics, finally to 1D fiber electronics (fibertronics). In this regard, fibertronic strategies toward wearable applications (e.g., electronic textiles (e-textiles)) have attracted considerable attention thanks to their capability to impart various functions into textiles with retaining textiles' intrinsic properties as well as imperceptible irritation by foreign matters. In recent years, extensive research has been carried out to develop various functional devices in the fiber form. Among various features, lighting and display features are the highly desirable functions in wearable electronics. This article discusses the recent progress of materials, architectural designs, and new fabrication technologies of fiber-shaped lighting devices and the current challenges corresponding to each device's operating mechanism. Moreover, opportunities and applications that the revolutionary convergence between the state-of-the-art fibertronic technology and age-long textile industry will bring in the future are also discussed.

Transcranial and systemic photobiomodulation for major depressive disorder: A systematic review of efficacy, tolerability and biological mechanisms

BACKGROUND

Photobiomodulation (PBM) with red and near-infrared light (NIR) -also known as Low-Level Light Therapy-is a low risk, inexpensive treatment-based on non-retinal exposure-under study for several neuropsychiatric conditions. The aim of this paper is to discuss the proposed mechanism of action and to perform a systematic review of pre-clinical and clinical studies on PBM for major depressive disorder (MDD).

METHODS

A search on MEDLINE and EMBASE databases was performed in July 2017. No time or language restrictions were used. Studies with a primary focus on MDD and presenting original data were included (n = 17). References on the mechanisms of action of PBM also included review articles and studies not focused on MDD.

RESULTS

Red and NIR light penetrate the skull and modulate brain cortex; an indirect effect of red and NIR light, when delivered non-transcranially, is also postulated. The main proposed mechanism for PBM is the enhancement of mitochondrial metabolism after absorption of NIR energy by the cytochrome C oxidase; however, actions on other pathways relevant to MDD are also reported. Studies on animal models indicate a benefit from PBM that is comparable to antidepressant medications. Clinical studies also indicate a significant antidepressant effect and good tolerability.

LIMITATIONS

Clinical studies are heterogeneous for population and treatment parameters, and most lack an appropriate control.

CONCLUSIONS

Preliminary evidence supports the potential of non-retinal PBM as a novel treatment for MDD. Future studies should clarify the ideal stimulation parameters as well as the overall efficacy, effectiveness and safety profile of this treatment.

Photodynamic and photobiological effects of light-emitting diode (LED) therapy in dermatological disease: an update

Benefit deriving from the use of light is known since ancient time, but, only in the last decades of twentieth century, we witnessed the rapid expansion of knowledge and techniques. Light-emitted diode (LED)-based devices represent the emerging and safest tool for the treatment of many conditions such as skin inflammatory conditions, aging, and disorders linked to hair growth. The present work reviews the current knowledge about LED-based therapeutic approaches in different skin and hair disorders. LED therapy represents the emerging and safest tool for the treatment of many conditions such as skin inflammatory conditions, aging, and disorders linked to hair growth. The use of LED in the treatment of such conditions has now entered common practice among dermatologists. Additional controlled studies are still needed to corroborate the efficacy of such kind of treatment.

The Role of Photodynamic Therapy in Acne: An Evidence-Based Review

BACKGROUND

Acne vulgaris is a highly prevalent skin disorder that affects almost all adolescents and can persist into adulthood. Photodynamic therapy (PDT) is an emerging treatment for acne that involves the use of a photosensitizer in combination with a light source and oxygen.

METHODS

We performed a systematic review of the literature and critically evaluated the studies. Sixty-nine clinical trials, four case reports, and two retrospective studies met the inclusion criteria, and seven of the studies were high quality.

RESULTS

The most common photosensitizers used were 5-aminolevulinic acid and methyl aminolevulinate, and both showed similar response. Red light was the most frequently used light source, followed by intense pulsed light, and showed comparable results. Inflammatory and non-inflammatory lesions both responded to treatment, with inflammatory lesions showing greater clearance in most studies. Adverse events associated with PDT for acne were mild and included pain on illumination and post-procedural erythema and edema. PDT has been safely used in higher Fitzpatrick skin types (III-IV), although these patients had a higher risk of transient hyperpigmentation.

CONCLUSION

This review supports PDT as an efficacious treatment for acne and a good adjunctive treatment for mild to severe acne, especially in patients who have not responded to topical therapy and oral antibacterials, and are not great candidates for isotretinoin. Further studies are warranted to evaluate the optimal photosensitizers, light sources, incubation times, and number of treatments for PDT use in acne.

Photoantimicrobials-are we afraid of the light?

Although conventional antimicrobial drugs have been viewed as miraculous cure-alls for the past 80 years, increasing antimicrobial drug resistance requires a major and rapid intervention. However, the development of novel but still conventional systemic antimicrobial agents, having only a single mode or site of action, will not alleviate the situation because it is probably only a matter of time until any such agents will also become ineffective. To continue to produce new agents based on this notion is unacceptable, and there is an increasing need for alternative approaches to the problem. By contrast, light-activated molecules called photoantimicrobials act locally via the in-situ production of highly reactive oxygen species, which simultaneously attack various biomolecular sites in the pathogenic target and therefore offer both multiple and variable sites of action. This non-specificity at the target circumvents conventional mechanisms of resistance and inhibits the development of resistance to the agents themselves. Photoantimicrobial therapy is safe and easy to implement and, unlike conventional agents, the activity spectrum of photoantimicrobials covers bacteria, fungi, viruses, and protozoa. However, clinical trials of these new, truly broad-spectrum, and minimally toxic agents have been few, and the funding for research and development is almost non-existent. Photoantimicrobials constitute one of the few ways forward through the morass of drug-resistant infectious disease and should be fully explored. In this Personal View, we raise awareness of the novel photoantimicrobial technologies that offer a viable alternative to conventional drugs in many relevant application fields, and could thus slow the pace of resistance development.

Light therapies for acne

BACKGROUND

Acne vulgaris is a very common skin problem that presents with blackheads, whiteheads, and inflamed spots. It frequently results in physical scarring and may cause psychological distress. The use of oral and topical treatments can be limited in some people due to ineffectiveness, inconvenience, poor tolerability or side-effects. Some studies have suggested promising results for light therapies.

OBJECTIVES

To explore the effects of light treatment of different wavelengths for acne.

SEARCH METHODS

We searched the following databases up to September 2015: the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, Embase and LILACS. We searched ISI Web of Science and Dissertation Abstracts International (from inception). We also searched five trials registers, and grey literature sources. We checked the reference lists of studies and reviews and consulted study authors and other experts in the field to identify further references to relevant randomised controlled trials (RCTs). We updated these searches in July 2016 but these results have not yet been incorporated into the review.

SELECTION CRITERIA

We included RCTs of light for treatment of acne vulgaris, regardless of language or publication status.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 71 studies, randomising a total of 4211 participants.Most studies were small (median 31 participants) and included participants with mild to moderate acne of both sexes and with a mean age of 20 to 30 years. Light interventions differed greatly in wavelength, dose, active substances used in photodynamic therapy (PDT), and comparator interventions (most commonly no treatment, placebo, another light intervention, or various topical treatments). Numbers of light sessions varied from one to 112 (most commonly two to four). Frequency of application varied from twice daily to once monthly.Selection and performance bias were unclear in the majority of studies. Detection bias was unclear for participant-assessed outcomes and low for investigator-assessed outcomes in the majority of studies. Attrition and reporting bias were low in over half of the studies and unclear or high in the rest. Two thirds of studies were industry-sponsored; study authors either reported conflict of interest, or such information was not declared, so we judged the risk of bias as unclear.Comparisons of most interventions for our first primary outcome 'Participant's global assessment of improvement' were not possible due to the variation in the interventions and the way the studies' outcomes were measured. We did not combine the effect estimates but rated the quality of the evidence as very low for the comparison of light therapies, including PDT to placebo, no treatment, topical treatment or other comparators for this outcome. One study which included 266 participants with moderate to severe acne showed little or no difference in effectiveness for this outcome between 20% aminolevulinic acid (ALA)-PDT (activated by blue light) versus vehicle plus blue light (risk ratio (RR) 0.87, 95% confidence interval (CI) 0.72 to 1.04, low-quality evidence). A study (n = 180) of a comparison of ALA-PDT (activated by red light) concentrations showed 20% ALA was no more effective than 15% (RR 1.05, 95% CI 0.96 to 1.15) but better than 10% ALA (RR 1.22, 95% CI 1.05 to 1.42) and 5% ALA (RR 1.47, 95% CI 1.19 to 1.81). The number needed to treat for an additional beneficial outcome (NNTB) was 6 (95% CI 3 to 19) and 4 (95% CI 2 to 6) for the comparison of 20% ALA with 10% and 5% ALA, respectively.For our second primary outcome 'Investigator-assessed changes in lesion counts', we combined three RCTs, with 360 participants with moderate to severe acne and found methyl aminolevulinate (MAL) PDT (activated by red light) was no different to placebo cream plus red light with regard to change in inflamed lesions (ILs) (mean difference (MD) -2.85, 95% CI -7.51 to 1.81), percentage change in ILs (MD -10.09, 95% CI -20.25 to 0.06), change in non-inflamed lesions (NILs) (MD -2.01, 95% CI -7.07 to 3.05), or in percentage change in NILs (MD -8.09, 95% CI -21.51 to 5.32). We assessed the evidence as moderate quality for these outcomes meaning that there is little or no clinical difference between these two interventions for lesion counts.Studies comparing the effects of other interventions were inconsistent or had small samples and high risk of bias. We performed only narrative synthesis for the results of the remaining trials, due to great variation in many aspects of the studies, poor reporting, and failure to obtain necessary data. Several studies compared yellow light to placebo or no treatment, infrared light to no treatment, gold microparticle suspension to vehicle, and clindamycin/benzoyl peroxide combined with pulsed dye laser to clindamycin/benzoyl peroxide alone. There were also several other studies comparing MAL-PDT to light-only treatment, to adapalene and in combination with long-pulsed dye laser to long-pulsed dye laser alone. None of these showed any clinically significant effects.Our third primary outcome was 'Investigator-assessed severe adverse effects'. Most studies reported adverse effects, but not adequately with scarring reported as absent, and blistering reported only in studies on intense pulsed light, infrared light and photodynamic therapies. We rated the quality of the evidence as very low, meaning we were uncertain of the adverse effects of the light therapies.Although our primary endpoint was long-term outcomes, less than half of the studies performed assessments later than eight weeks after final treatment. Only a few studies assessed outcomes at more than three months after final treatment, and longer-term assessments are mostly not covered in this review.

AUTHORS' CONCLUSIONS

High-quality evidence on the use of light therapies for people with acne is lacking. There is low certainty of the usefulness of MAL-PDT (red light) or ALA-PDT (blue light) as standard therapies for people with moderate to severe acne.Carefully planned studies, using standardised outcome measures, comparing the effectiveness of common acne treatments with light therapies would be welcomed, together with adherence to the Consolidated Standards of Reporting Trials (CONSORT) guidelines.

Review of transcranial photobiomodulation for major depressive disorder: targeting brain metabolism, inflammation, oxidative stress, and neurogenesis

We examined the use of near-infrared and red radiation (photobiomodulation, PBM) for treating major depressive disorder (MDD). While still experimental, preliminary data on the use of PBM for brain disorders are promising. PBM is low-cost with potential for wide dissemination; further research on PBM is sorely needed. We found clinical and preclinical studies via PubMed search (2015), using the following keywords: "near-infrared radiation," "NIR," "low-level light therapy," "low-level laser therapy," or "LLLT" plus "depression." We chose clinically focused studies and excluded studies involving near-infrared spectroscopy. In addition, we used PubMed to find articles that examine the link between PBM and relevant biological processes including metabolism, inflammation, oxidative stress, and neurogenesis. Studies suggest the processes aforementioned are potentially effective targets for PBM to treat depression. There is also clinical preliminary evidence suggesting the efficacy of PBM in treating MDD, and comorbid anxiety disorders, suicidal ideation, and traumatic brain injury. Based on the data collected to date, PBM appears to be a promising treatment for depression that is safe and well-tolerated. However, large randomized controlled trials are still needed to establish the safety and effectiveness of this new treatment for MDD.

Infrared and skin: Friend or foe

In the last decade, it has been proposed that the sun's IR-A wavelengths might be deleterious to human skin and that sunscreens, in addition to their desired effect to protect against UV-B and UV-A, should also protect against IR-A (and perhaps even visible light). Several studies showed that NIR may damage skin collagen content via an increase inMMP-1 activity in the same manner as is known for UVR. Unfortunately, the artificial NIR light sources used in such studies were not representative of the solar irradiance. Yet, little has been said about the other side of the coin. This article will focus on key information suggesting that IR-A may be more beneficial than deleterious when the skin is exposed to the appropriate irradiance/dose of IR-A radiation similar to daily sun exposure received by people in real life.IR-A might even precondition the skin--a process called photo prevention--from an evolutionary standpoint since exposure to early morning IR-A wavelengths in sunlight may ready the skin for the coming mid-day deleterious UVR. Consequently IR-A appears to be the solution, not the problem. It does more good than bad for the skin. It is essentially a question of intensity and how we can learn from the sun. © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Current evidence and applications of photodynamic therapy in dermatology

In photodynamic therapy (PDT) a photosensitizer – a molecule that is activated by light – is administered and exposed to a light source. This leads both to destruction of cells targeted by the particular type of photosensitizer, and immunomodulation. Given the ease with which photosensitizers and light can be delivered to the skin, it should come as no surprise that PDT is an increasingly utilized therapeutic in dermatology. PDT is used commonly to treat precancerous cells, sun-damaged skin, and acne. It has reportedly also been used to treat other conditions including inflammatory disorders and cutaneous infections. This review discusses the principles behind how PDT is used in dermatology, as well as evidence for current applications of PDT.

Field treatment of facial and scalp actinic keratoses with photodynamic therapy: survey of patient perceptions of treatment satisfaction and outcomes

BACKGROUND

Diffuse field change with actinic keratoses (AK) is a ubiquitous skin disease in Australia, with potential for malignant transformation. We report on 35 consecutive patients who had field therapy with single session photodynamic therapy (PDT) using 1 h incubation time for 5-aminolevulinic acid (5-ALA) or 3 h for methyl-aminolevulinate (MAL).

METHODS

We retrospectively telephone surveyed our patient cohort regarding their satisfaction and perceptions of the effectiveness, side-effect profile and benefits of PDT. We also reviewed all patients' notes for significant side-effects.

RESULTS

Sixty-nine per cent (n = 24/35) of patients responded to the telephone survey; 66% (n = 16/24) of the respondents reported good clearance of AK and claimed a good cosmetic outcome. All respondents reported moderate or severe pain (42% and 58%, respectively) during the illumination phase. Twenty per cent of all patients treated had suffered from one or more of the following side-effects: pustulation; severe erythema; and skin erosions.

CONCLUSIONS

Overall, our results compared favourably with previously published studies using 5-ALA or MAL PDT. However, our patient cohort experienced a greater side-effect profile. This may have been due to our patients having greater disease burden compared to other studies and possibly due to our use of topical retinoids prior to PDT in selected patients.

Management strategies for acne vulgaris

CLINICAL QUESTION

What are the most effective treatment(s) for mild, moderate, severe, and hormonally driven acne?

RESULTS

Mild acne responds favorably to topical treatments such as benzoyl peroxide, salicylic acid, and a low-dose retinoid. Moderate acne responds well to combination therapy comprising-topical benzoyl peroxide, antibiotics, and/or retinoids, as well as oral antibiotics in refractory cases and oral contraceptive pills for female acne patients. Severe nodulocystic acne vulgaris responds best to oral isotretinoin therapy. In female patients with moderate to severe acne, facial hair, loss of scalp hair and irregular periods, polycystic ovarian syndrome should be considered and appropriate treatment with hormonal modulation given. Adjunctive procedures can also be considered for all acne patients.

IMPLEMENTATION

PITFALLS TO AVOID WHEN TREATING ACNE: treatment of acne in women of child-bearing age; familiarization of all acne treatments in order to individualize management for patients; indications for specialist referral.

New approaches in light/laser therapies and photodynamic treatment of acne

Acne is a domain in which the technology and understanding of light/laser therapeutic procedures have advanced considerably. The aim of the paper was to revisit adjunctive physical treatments of acne, including light/laser treatments and photodynamic therapy. This review summarizes findings about such treatment modalities with particular emphasis on efficacy and safety. A number of laser/light-based modalities have been developed to meet the increasing demand for new acne treatments. The current devices correspond, on the one hand, to light-emitting diode therapy and, on the other hand, to the 532-nm potassium titanyl phosphate laser, the 585- and 595-nm pulsed dye laser, the 1450-nm diode laser, the 1320-nm Nd:YAG laser and intense pulsed light. Photodynamic therapy is also available. It is claimed that light/laser treatments might induce a faster response compared with the 1-3 months needed for response to traditional oral and topical treatments. In conclusion, pulsed dye laser shows efficacy in some patients with mild to moderate acne. The relative effectiveness compared with other treatments is unconfirmed; from the published information, evidence-based efficacy assessment of light/laser therapies in acne remains almost impossible.