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Author Souman, J.L.; Borra, T.; de Goijer, I.; Schlangen, L.J.M.; Vlaskamp, B.N.S.; Lucassen, M.P.
Title Spectral Tuning of White Light Allows for Strong Reduction in Melatonin Suppression without Changing Illumination Level or Color Temperature Type Journal Article
Year 2018 Publication Journal of Biological Rhythms Abbreviated Journal J Biol Rhythms
Volume 33 Issue 4 Pages 420-431
Keywords Human Health; Lighting
Abstract Studies with monochromatic light stimuli have shown that the action spectrum for melatonin suppression exhibits its highest sensitivity at short wavelengths, around 460 to 480 nm. Other studies have demonstrated that filtering out the short wavelengths from white light reduces melatonin suppression. However, this filtering of short wavelengths was generally confounded with reduced light intensity and/or changes in color temperature. Moreover, it changed the appearance from white light to yellow/orange, rendering it unusable for many practical applications. Here, we show that selectively tuning a polychromatic white light spectrum, compensating for the reduction in spectral power between 450 and 500 nm by enhancing power at even shorter wavelengths, can produce greatly different effects on melatonin production, without changes in illuminance or color temperature. On different evenings, 15 participants were exposed to 3 h of white light with either low or high power between 450 and 500 nm, and the effects on salivary melatonin levels and alertness were compared with those during a dim light baseline. Exposure to the spectrum with low power between 450 and 500 nm, but high power at even shorter wavelengths, did not suppress melatonin compared with dim light, despite a large difference in illuminance (175 vs. <5 lux). In contrast, exposure to the spectrum with high power between 450 and 500 nm (also 175 lux) resulted in almost 50% melatonin suppression. For alertness, no significant differences between the 3 conditions were observed. These results open up new opportunities for lighting applications that allow for the use of electrical lighting without disturbance of melatonin production.
Address Philips Lighting Research, Department Lighting Applications, Eindhoven, The Netherlands
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0748-7304 ISBN Medium
Area Expedition Conference
Notes PMID:29984614 Approved no
Call Number (up) GFZ @ kyba @ Serial 1985
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Author Ostrin, L.A.
Title Ocular and systemic melatonin and the influence of light exposure Type Journal Article
Year 2018 Publication Clinical & Experimental Optometry Abbreviated Journal Clin Exp Optom
Volume in press Issue Pages in press
Keywords Vision; Review; Human Health
Abstract Melatonin is a neurohormone known to modulate a wide range of circadian functions, including sleep. The synthesis and release of melatonin from the pineal gland is heavily influenced by light stimulation of the retina, particularly through the intrinsically photosensitive retinal ganglion cells. Melatonin is also synthesised within the eye, although to a much lesser extent than in the pineal gland. Melatonin acts directly on ocular structures to mediate a variety of diurnal rhythms and physiological processes within the eye. The interactions between melatonin, the eye, and visual function have been the subject of a considerable body of recent research. This review is intended to provide a broad introduction for eye-care practitioners and researchers to the topic of melatonin and the eye. The first half of the review describes the anatomy and physiology of melatonin production: how visual inputs affect the pineal production of melatonin; how melatonin is involved in a variety of diurnal rhythms within the eye, including photoreceptor disc shedding, neuronal sensitivity, and intraocular pressure control; and melatonin production and physiological roles in retina, ciliary body, lens and cornea. The second half of the review describes clinical implications of light/melatonin interactions. These include light exposure and photoreceptor contributions in melatonin suppression, leading to consideration of how blue blockers, cataract, and light therapy might affect sleep and mood in patients. Additionally, the interactions between melatonin, sleep and refractive error development are discussed. A better understanding of environmental factors that affect melatonin and subsequent effects on physiological processes will allow clinicians to develop treatments and recommend modifiable behaviours to improve sleep, increase daytime alertness, and regulate ocular and systemic processes related to melatonin.
Address University of Houston College of Optometry, Houston, Texas, USA
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0816-4622 ISBN Medium
Area Expedition Conference
Notes PMID:30074278 Approved no
Call Number (up) GFZ @ kyba @ Serial 1986
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Author Mard, J.; Di Baldassarre, G.; Mazzoleni, M.
Title Nighttime light data reveal how flood protection shapes human proximity to rivers Type Journal Article
Year 2018 Publication Science Advances Abbreviated Journal Sci Adv
Volume 4 Issue 8 Pages eaar5779
Keywords Remote Sensing
Abstract To understand the spatiotemporal changes of flood risk, we need to determine the way in which humans adapt and respond to flood events. One adaptation option consists of resettling away from flood-prone areas to prevent or reduce future losses. We use satellite nighttime light data to discern the relationship between long-term changes in human proximity to rivers and the occurrence of catastrophic flood events. Moreover, we explore how these relationships are influenced by different levels of structural flood protection. We found that societies with low protection levels tend to resettle further away from the river after damaging flood events. Conversely, societies with high protection levels show no significant changes in human proximity to rivers. Instead, such societies continue to rely heavily on structural measures, reinforcing flood protection and quickly resettling in flood-prone areas after a flooding event. Our work reveals interesting aspects of human adaptation to flood risk and offers key insights for comparing different risk reduction strategies. In addition, this study provides a framework that can be used to further investigate human response to floods, which is relevant as urbanization of floodplains continues and puts more people and economic assets at risk.
Address IHE Delft Institute for Water Education, 2611 AX Delft, Netherlands
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2375-2548 ISBN Medium
Area Expedition Conference
Notes PMID:30140738; PMCID:PMC6105301 Approved no
Call Number (up) GFZ @ kyba @ Serial 1989
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Author Wilson IV, J.; Reid, K.J.; Braun, R.I.; Abbott, S.M.; Zee, P.C.
Title Habitual Light Exposure Relative to Circadian Timing in Delayed Sleep-Wake Phase Disorder Type Journal Article
Year 2018 Publication Sleep Abbreviated Journal
Volume in press Issue Pages
Keywords Human Health
Abstract Study Objectives

To compare melatonin timing, a well validated marker for endogenous circadian phase, and habitual light exposure patterns in adults with delayed sleep-wake phase disorder (DSWPD) and intermediate chronotype controls.

Methods

12 individuals with DSWPD (5 females, mean age 31.1) and 12 age matched controls (6 females, mean age 33.6) underwent a minimum of seven days of light and activity monitoring followed by an inpatient hospital stay, where blood was taken to assess melatonin timing (calculated as dim light melatonin onset – DLMO). Habitual light exposure patterns were then compared to a human phase response curve (PRC) to light.

Results

Relative to clock time, individuals with DSWPD had a later light exposure pattern compared to controls, but their light exposure pattern was earlier relative to DLMO. According to the human phase response curve (PRC) to light, individuals with DSWPD had less daily advancing light exposure compared to controls. The primary difference was seen in the late portion of the advancing window, in which individuals with DSWPD were exposed to fewer pulses of light of equivalent duration and intensity compared to controls.

Conclusions

Diminished advancing light exposure may play a role in the development and perpetuation of delayed sleep-wake timing in individuals with DSWPD. Enhancing light exposure during the later portion of the advancing window represents an innovative and complementary strategy that has the potential to improve the effectiveness of bright light therapy in DSWPD.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0161-8105 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number (up) GFZ @ kyba @ Serial 1990
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Author Suh, Y.-W.; Na, K.-H.; Ahn, S.-E.; Oh, J.
Title Effect of Ambient Light Exposure on Ocular Fatigue during Sleep Type Journal Article
Year 2018 Publication Journal of Korean Medical Science Abbreviated Journal J Korean Med Sci
Volume 33 Issue 38 Pages
Keywords Human Health
Abstract Background

To investigate the influence of nocturnal ambient light on visual function and ocular fatigue.

Methods

Sixty healthy subjects (30 males and 30 females) aged 19 through 29 years with no history of ocular disease were recruited. All subjects spent 3 consecutive nights in the sleep laboratory. During the first and second nights, the subjects were not exposed to light during sleep, but during the third night, they were exposed to ambient light, measuring 5 or 10 lux at the eye level, which was randomly allocated with 30 subjects each. The visual function and ocular fatigue were assessed at 7 a.m. on the 3rd and 4th mornings, using best-corrected visual acuity, refractive error, conjunctival hyperemia, tear break-up time, maximal blinking interval, ocular surface temperature, and subjective symptoms reported on a questionnaire.

Results

Three male and three female subjects failed to complete the study (4 in the 5 lux; 2 from the 10 lux). For the entire 54 subjects, tear break-up time and maximal blinking interval decreased (P = 0.015; 0.010, respectively), and nasal and temporal conjunctival hyperemia increased significantly after sleep under any ambient light (P < 0.001; 0.021, respectively). Eye tiredness and soreness also increased (P = 0.004; 0.024, respectively). After sleep under 5 lux light, only nasal conjunctival hyperemia increased significantly (P = 0.008). After sleep under 10 lux light, nasal and temporal conjunctival hyperemia, eye tiredness, soreness, difficulty in focusing, and ocular discomfort increased significantly (P < 0.05).

Conclusion

Nocturnal ambient light exposure increases ocular fatigue. Avoiding ambient light during sleep could be recommended to prevent ocular fatigue.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1011-8934 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number (up) GFZ @ kyba @ Serial 1991
Permanent link to this record