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https://hdl.handle.net/2115/84187

Effects of different light incident angles via a head-mounted device on the magnitude of nocturnal melatonin suppression in healthy young subjects

英語

Humans

2022-01-21

Springer

Sleep and biological rhythms

20

247-254

Bright light is a primary zeitgeber (synchronizer) for the central circadian pacemaker in humans. Recently, head-mounted devices for light therapy have been developed to treat patients suffering from circadian rhythm sleep disorders. In this study, to evaluate the influence of the light incident angle of head-mounted devices on the human circadian pacemaker, we examined the effects of bright light (ca.10000 lx) from two different angles (55 degrees vs. 28 degrees) on the suppression of melatonin secretion at night. Twenty-nine subjects (25.1 +/- 6.3 SD years) participated in the present study. The subjects were kept under dim light conditions (< 5 lx) from 4 h before their habitual bedtime, followed by exposure to 1 h of bright light at two different angles during their habitual bedtime. Saliva samples were collected every hour under dim light conditions and then collected every 30 min during the bright light exposure. To assess the effect of the light incident angle on ipRGCs mediating light-evoked pupillary constriction, pupil size was measured in before and after exposure to bright light. Melatonin suppression in the group exposed to light at 28 degrees was significantly higher than that in the group with light at 55 degrees (p < 0.001). The pupillary constriction was significantly greater in the group exposed to light at 28 degrees than that in the group with light at 55 degrees (p < 0.001). The present findings suggest that the light incident angle is an important factor for bright light therapy and should be considered to effectively use head-mounted devices in home and clinical settings.

学術雑誌論文

Version of Record

1446-9235

1479-8425

AA11807852