|   | 
Details
   web
Records
Author Ostrin, L.A.
Title Ocular and systemic melatonin and the influence of light exposure Type Journal Article
Year 2018 Publication (up) 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 GFZ @ kyba @ Serial 1986
Permanent link to this record
 

 
Author Lowden, A.; Lemos, N.; Gonçalves, B.; Öztürk, G.; Louzada, F.; Pedrazzoli, M.; Moreno, C.
Title Delayed Sleep in Winter Related to Natural Daylight Exposure among Arctic Day Workers Type Journal Article
Year 2018 Publication (up) Clocks & Sleep Abbreviated Journal Clocks & Sleep
Volume 1 Issue 1 Pages 105-116
Keywords Human Health
Abstract Natural daylight exposures in arctic regions vary substantially across seasons. Negative consequences have been observed in self-reports of sleep and daytime functions during the winter but have rarely been studied in detail. The focus of the present study set out to investigate sleep seasonality among indoor workers using objective and subjective measures. Sleep seasonality among daytime office workers (n = 32) in Kiruna (Sweden, 67.86° N, 20.23° E) was studied by comparing the same group of workers in a winter and summer week, including work and days off at the weekend, using actigraphs (motion loggers) and subjective ratings of alertness and mood. Actigraph analyses showed delayed sleep onset of 39 min in winter compared to the corresponding summer week (p < 0.0001) and shorter weekly sleep duration by 12 min (p = 0.0154). A delay of mid-sleep was present in winter at workdays (25 min, p < 0.0001) and more strongly delayed during days off (46 min, p < 0.0001). Sleepiness levels were higher in winter compared to summer (p < 0.05). Increased morning light exposure was associated with earlier mid-sleep (p < 0.001), while increased evening light exposure was associated with delay (p < 0.01). This study confirms earlier work that suggests that lack of natural daylight delays the sleep/wake cycle in a group of indoor workers, despite having access to electric lighting. Photic stimuli resulted in a general advanced sleep/wake rhythm during summer and increased alertness levels.
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 2624-5175 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2137
Permanent link to this record
 

 
Author Prayag, A.; Münch, M.; Aeschbach, D.; Chellappa, S.; Gronfier, C.
Title Light Modulation of Human Clocks, Wake, and Sleep Type Journal Article
Year 2019 Publication (up) Clocks & Sleep Abbreviated Journal Clocks & Sleep
Volume 1 Issue 1 Pages 193-208
Keywords Human Health; Review
Abstract Light, through its non-imaging forming effects, plays a dominant role on a myriad of physiological functions, including the human sleep–wake cycle. The non-image forming effects of light heavily rely on specific properties such as intensity, duration, timing, pattern, and wavelengths. Here, we address how specific properties of light influence sleep and wakefulness in humans through acute effects, e.g., on alertness, and/or effects on the circadian timing system. Of critical relevance, we discuss how different characteristics of light exposure across the 24-h day can lead to changes in sleep–wake timing, sleep propensity, sleep architecture, and sleep and wake electroencephalogram (EEG) power spectra. Ultimately, knowledge on how light affects sleep and wakefulness can improve light settings at home and at the workplace to improve health and well-being and optimize treatments of chronobiological disorders.
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 2624-5175 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2266
Permanent link to this record
 

 
Author Walbeek, T.J.; Harrison, E.M.; Soler, R.R.; Gorman, M.R.
Title Enhanced Circadian Entrainment in Mice and Its Utility under Human Shiftwork Schedules Type Journal Article
Year 2019 Publication (up) Clocks & Sleep Abbreviated Journal Clocks & Sleep
Volume 1 Issue 3 Pages 394-413
Keywords Animals
Abstract The circadian system is generally considered to be incapable of adjusting to rapid changes in sleep/work demands. In shiftworkers this leads to chronic circadian disruption and sleep loss, which together predict underperformance at work and negative health consequences. Two distinct experimental protocols have been proposed to increase circadian flexibility in rodents using dim light at night: rhythm bifurcation and T-cycle (i.e., day length) entrainment. Successful translation of such protocols to human shiftworkers could facilitate alignment of internal time with external demands. To assess entrainment flexibility following bifurcation and exposure to T-cycles, mice in Study 1 were repeatedly phase-shifted. Mice from experimental conditions rapidly phase-shifted their activity, while control mice showed expected transient misalignment. In Study 2 and 3, mice followed a several weeks-long intervention designed to model a modified DuPont or Continental shiftwork schedule, respectively. For both schedules, bifurcation and nocturnal dim lighting reduced circadian misalignment. Together, these studies demonstrate proof of concept that mammalian circadian systems can be rendered sufficiently flexible to adapt to multiple, rapidly changing shiftwork schedules. Flexible adaptation to exotic light-dark cycles likely relies on entrainment mechanisms that are distinct from traditional entrainment.
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 2624-5175 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2661
Permanent link to this record
 

 
Author Aarts, M.P.J.; Hartmeyer, S.L.; Morsink, K.; Kort, H.S.M.; de Kort, Y.A.W.
Title Can Special Light Glasses Reduce Sleepiness and Improve Sleep of Nightshift Workers? A Placebo-Controlled Explorative Field Study Type Journal Article
Year 2020 Publication (up) Clocks & Sleep Abbreviated Journal Clocks & Sleep
Volume 2 Issue 2 Pages 225-245
Keywords Human Health
Abstract Nightshift workers go against the natural sleep–wake rhythm. Light can shift the circadian clock but can also induce acute alertness. This placebo-controlled exploratory field study examined the effectiveness of light glasses to improve alertness while reducing the sleep complaints of hospital nurses working nightshifts. In a crossover within-subjects design, 23 nurses participated, using treatment glasses and placebo glasses. Sleepiness and sleep parameters were measured. A linear mixed model analysis on sleepiness revealed no significant main effect of the light intervention. An interaction effect was found indicating that under the placebo condition, sleepiness was significantly higher on the first nightshift than on the last night, while under the treatment condition, sleepiness remained stable across nightshift sessions. Sleepiness during the commute home also showed a significant interaction effect, demonstrating that after the first nightshift, driver sleepiness was higher for placebo than for treatment. Subjective sleep quality showed a negative main effect of treatment vs. placebo, particularly after the first nightshift. In retrospect, both types of light glasses were self-rated as effective. The use of light glasses during the nightshift may help to reduce driver sleepiness during the commute home, which is relevant, as all participants drove home by car or (motor) bike.
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 2624-5175 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2977
Permanent link to this record