Wearing blue light-blocking glasses in the evening advances circadian rhythms in the patients with delayed sleep phase disorder: An open-label trial

ABSTRACT

It has been recently discovered that blue wavelengths form the portion of the visible electromagnetic spectrum that most potently regulates circadian rhythm. We investigated the effect of blue light-blocking glasses in subjects with delayed sleep phase disorder (DSPD). This open-label trial was conducted over 4 consecutive weeks. The DSPD patients were instructed to wear blue light-blocking amber glasses from 21:00 p.m. to bedtime, every evening for 2 weeks. To ascertain the outcome of this intervention, we measured dim light melatonin onset (DLMO) and actigraphic sleep data at baseline and after the treatment. Nine consecutive DSPD patients participated in this study. Most subjects could complete the treatment with the exception of one patient who hoped for changing to drug therapy before the treatment was completed. The patients who used amber lens showed an advance of 78 min in DLMO value, although the change was not statistically significant (p = 0.145). Nevertheless, the sleep onset time measured by actigraph was advanced by 132 min after the treatment (p = 0.034). These data suggest that wearing amber lenses may be an effective and safe intervention for the patients with DSPD. These findings also warrant replication in a larger patient cohort with controlled observations.

KEYWORDS:

• Delayed sleep phase disorder
• amber lens
• blue light
• sleep onset
• dim light melatonin onset

Acknowledgments

The authors are grateful to the patients who participated in this study and thank MARUZEN Editing Light service (http://kw.maruzen.co.jp/kousei-honyaku/) for English language review.

Declaration of interest statement

The authors report no conflicts of interest in this research. Dr Kitajima has received speaker’s honoraria from Eizai, Mitsubishi Tanabe, Otsuka, Takeda, Eli Lilly, MSD, Yoshitomi, Fukuda, Dainippon Sumitomo, and Shionogi and has received research grant from Eizai, MSD and Takeda. Dr. Iwata has received speaker’s honoraria from Astellas, Dainippon Sumitomo, Eli Lilly, GlaxoSmithKline, Janssen, Yoshitomi, Otsuka, Meiji, Shionogi, Novartis, and Pfizer and has research grants from Dainippon Sumitomo, GlaxoSmithKline, Tanabe-Mitsubishi and Otsuka.