The effect of indoor daylight spectrum and intensity on viability of indoor pathogens on different surface materials.

Built environments play a key role in the transmission of infectious diseases. Ventilation rates, air temperature, and humidity affect airborne transmission while cleaning protocols, material properties and light exposure can influence viability of pathogens on surfaces. We investigated how indoor daylight intensity and spectrum through electrochromic (EC) windows can impact the growth rate and viability of indoor pathogens on different surface materials (polyvinyl chloride [PVC] fabric, polystyrene, and glass) compared to traditional blinds. Results showed that tinted EC windows let in higher energy, shorter wavelength daylight than those with clear window and blind. The growth rates of pathogenic bacteria and fungi were significantly lower in spaces with EC windows compared to blinds: nearly 100% growth rate reduction was observed when EC windows were in their clear state followed by 41%-100% reduction in bacterial growth rate and 26%-42% reduction in fungal growth rate when EC windows were in their darkest tint. Moreover, bacterial viabilities were significantly lower on PVC fabric when they were exposed to indoor light at EC-tinted window. These findings are deemed fundamental to the design of healthy modern buildings, especially those that encompass sick and vulnerable individuals.

Is a 4 J/cm2 PpIX-Weighted Simulated Daylight (SDL-PDT) Dose Still Efficient for Photodynamic Therapy of Actinic Keratosis?

Background: Several solutions are now proposed to provide indoor illumination with so-called artificial white light or simulated daylight (SDL-PDT), resulting in an effective treatment for actinic keratosis (AK). However, the optimal PpIX-weighted light dose is still debated. Integrating the effective irradiance over the irradiation time yields the effective light dose, which is also known as the protoporphyrin IX-weighted light dose and is a key parameter for the efficacy of the treatment. Objectives: The paper aims to report the clinical outcomes of SDL-PDT when using the PpIX-weighted light dose of 4 J/cm2, in patients treated for AK lesions of the scalp or the face at our medical dermatology center (ClinicalTrials.gov NCT052036). Methods: A total of 30 patients (16 males, 14 females), with a mean age of 71.0 ± 10.2, with phototype 1 (16 patients) and phototype 2 (14 patients) with grade I-II AK were treated with a drug light interval (DLI) of 10 min and a light exposure of 35 min (Dermaris, Surgiris, Croix, France), corresponding to a PpIX-weighted light dose of 4 J/cm2. The primary endpoint was the cure rate of patients at six months post-treatment. Secondary endpoints included scores of pain, erythema, crusts, and discomfort during or/and post the treatment. Results: In total, 762 AK were treated. Six months following treatment, the cure rate of the patients was 77%. The median pain score was less than 1 out of 10 for most of the patients. Erythema was observed in all patients and lasted 3 days (±1.5 day). Crusts were seen in 28 patients. Discomfort was reported as mild or less in more than 97% of patients. Conclusions: The shortening of the PpIX-weighted light dose to 4 J/cm2, corresponding to an illumination duration of 35 min with the Dermaris, does not modify the efficacy of the SDL-PDT. This observation is in agreement with recent published data demonstrating that the light dose can be reduced. Furthermore, this clinical study confirmed that SDL-PDT is an effective and nearly painless treatment with minimal side effects for patients with AK lesions of the scalp.

A randomized split-face clinical trial of conventional vs indoor-daylight photodynamic therapy for the treatment of multiple actinic keratosis of the face and scalp and photoaging.

BACKGROUND: Recently, indoor daylight photodynamic therapy (idl-PDT) has been developed; however, its efficacy and tolerability remain to be assessed. OBJECTIVE: This is a not-inferiority study to compare treatment outcomes of cPDT with a red LED lamp and idlPDT with a polychromatic white LED lamp in adult patients affected by symmetrical AKs of face and/or scalp. METHODS: In this comparative, intra-patient, split-face, randomized clinical trial forty-three adult patients were enrolled. Two contralateral and symmetrical target areas of the face and/or scalp harboring at least 5 AKs were selected and randomized 1:1 to treatment with cPDT and idlPDT. The AKs number and cumulative area were assessed at baseline (T0). Efficacy and cosmetic outcome were assessed 3 months after treatment (T1). RESULTS: Total AKs number and area reduced significantly with both idlPDT (p < .0001) and cPDT (p < .0001) in comparison to baseline. cPDT was more painful (p < .0001) and induced a more severe inflammation (p < .0001). Twenty-nine patients (70.7%) gave their overall preference to idlPDT (p < .001). CONCLUSION: idlPDT may represent an alternative treatment protocol to cPDT for in-office treatment of AKs patients with better tolerability and a not inferior efficacy.

Bringing the gentle properties of daylight photodynamic therapy indoors: A systematic review of efficacy and safety.

Classic photodynamic therapy (PDT) is an effective, but painful, treatment of actinic keratosis (AK). Daylight PDT with simultaneous activation of protoporphyrin IX during its formation is almost painless and as effective. Recent studies suggest that this gentle simultaneous activation can be performed indoors by replacing daylight with a suitable light source. We aimed to systematically review efficacy and tolerability of indoor gentle PDT of AKs using various light sources. We systematically searched MEDLINE, Embase, and the Cochrane Library for clinical studies of treatment efficacy or adverse events. Indoor gentle PDT consists of application of methyl aminolevulinate or 5-aminolevulinic acid on the skin prior to long time illumination, starting no later than one hour after application. Fifteen studies met the selection criteria, enrolling 518 patients with more than 5,000 AKs undergoing indoor gentle PDT. The studies mainly included thin AKs comprised of 8 uncontrolled studies and 7 randomized controlled trials (RCT) of which 3 were designed as non-inferiority RCTs. Results from both controlled and uncontrolled trials indicated good treatment tolerability with very low pain scores like those of daylight PDT. Reduction of AK lesions 3 months after indoor gentle PDT in RCTs ranged from 52% to 79%, which is comparable to classic and daylight PDT. All 3 non-inferiority RCTs reported that indoor gentle PDT was non-inferior in terms of efficacy to classic PDT. The included studies used varying treatment protocols with different pretreatments, incubation time, light sources, and irradiation time. No standard protocol for indoor gentle PDT exists yet.

Randomized Clinical Trial of Conventional versus Indoor Daylight Photodynamic Therapy for Treatment of Actinic Cheilitis.

INTRODUCTION: Actinic cheilitis (AC) is the biologic precursor of invasive squamous cell carcinoma (SCC) of the vermilion, and different treatment options have been investigated, but their efficacy is hampered by local inflammation, pain and slow recovery. Daylight photodynamic therapy (dl-PDT) has been demonstrated to represent a valuable treatment option for AC, but its feasibility is limited by weather conditions and latitude. METHODS: Our study proposed to compare the efficacy and tolerability of conventional photodynamic therapy (c-PDT) and indoor daylight photodynamic therapy (idl-PDT) with a white LED lamp for the treatment of AC. Sixteen patients were enrolled in the study: 8 (50%) treated with c-PDT and 8 (50%) treated with idl-PDT. All patients completed the study protocol. RESULTS: Both idl-PDT and c-PDT were demonstrated to be highly effective in terms of reduction of the cumulative lesional area and severity of the clinical score. Neither treatment was inferior to the other. The inflammatory reaction and the pain scores were milder with idl-PDT, whereas the cosmetic outcome was not different. CONCLUSION: The present findings confirm that idl-PDT can represent a valid therapeutic strategy for AC patients as well, despite the procedural difficulties and the risk of poor tolerability related to the body site.

The Effect of Indoor Daylight Levels on Hospital Costs and Length of Stay of Patients Admitted to General Surgery.

BACKGROUND: Indoor daylight levels can directly affect the physical and psychological state of people. However, the effect of indoor daylight levels on the clinical recovery process of the patient remains controversial. This study was to evaluate the effect of indoor daylight levels on hospital costs and the average length of stay (LOS) of a large patient population in general surgery wards. METHODS: Data were collected retrospectively and analyzed of patients in the Second Affiliated Hospital of Zhejiang University, School of Medicine between January 2015 and August 2020. We measured daylight levels in the patient rooms of general surgery and assessed their association with the total hospital costs and LOS of the patients. RESULTS: A total of 2,998 patients were included in this study with 1,478 each assigned to two daylight level groups after matching. Overall comparison of hospital total costs and LOS among patients according to daylight levels did not show a significant difference. Subgroup analysis showed when exposed to higher intensity of indoor daylight, illiterate patients had lower total hospital costs (CNY ¥13070.0 vs. ¥15210.3, p = 0.018) and shorter LOS (7 vs. 10 days, p = 0.011) as compared to those exposed to a lower intensity. CONCLUSIONS: Indoor daylight levels were not associated with the hospital costs and LOS of patients in the wards of general surgery, except for those who were illiterate. It might be essential to design guidelines for medical staff and healthcare facilities to enhance the indoor environmental benefits of daylight for some specific populations.

Dementia Enlightened?! A Systematic Literature Review of the Influence of Indoor Environmental Light on the Health of Older Persons with Dementia in Long-Term Care Facilities.

Light therapy for older persons with dementia is often administered with light boxes, even though indoor ambient light may more comfortably support the diverse lighting needs of this population. Our objective is to investigate the influence of indoor daylight and lighting on the health of older adults with dementia living in long-term care facilities. A systematic literature search was performed within PubMed, CINAHL, PsycINFO, Web of Science and Scopus databases. The included articles (n=37) were published from 1991 to 2020. These articles researched the influence of existing and changed indoor light conditions on health and resulted in seven categories of health outcomes. Although no conclusive evidence was found to support the ability of indoor light to decrease challenging behaviors or improve circadian rhythms, findings of two studies indicate that exposure to (very) cool light of moderate intensity diminished agitation. Promising effects of indoor light were to reduce depressive symptoms and facilitate spatial orientation. Furthermore, there were indications that indoor light improved one's quality of life. Despite interventions with dynamic lighting having yielded little evidence of its efficacy, its potential has been insufficiently researched among this study population. This review provides a clear and comprehensive description of the impact of diverse indoor light conditions on the health of older adults with dementia living in long-term care facilities. Variation was seen in terms of research methods, (the description of) light conditions, and participants' characteristics (types and severity of dementia), thus confounding the reliability of the findings. The authors recommend further research to corroborate the beneficial effects of indoor light on depression and to clarify its role in supporting everyday activities of this population. An implication for practice in long-term care facilities is raising the awareness of the increased lighting needs of aged residents.