Effect of Morning Light Glasses and Night Short-Wavelength Filter Glasses on Sleep-Wake Rhythmicity in Medical Inpatients

Abstract

Sleep and circadian rhythm disorders are common amongst medical inpatients. They are caused by a mixture of factors, including noise, loss of habitual daily routines, and abnormal exposure to light, which tends to be insufficient in the day and too high at night. The aim of the present study was to test the efficacy of morning light therapy plus night short-wavelength filter glasses on sleep quality/timing, and sleepiness/mood over the daytime hours, in a group of well-characterized medical inpatients. Thirty-three inpatients were enrolled and randomized (2:1) to either treatment (n = 22; 13 males, 48.3 ± 13.3 years) or standard of care (n = 11; 8 males, 56.9 ± 12.9 years). On admission, all underwent a baseline assessment of sleep quality/timing and diurnal preference. During hospitalization they underwent monitoring of sleep quality/timing (sleep diaries and actigraphy), plus hourly assessment of sleepiness/mood during the daytime hours on one, standard day of hospitalization. Patients in the treatment arm were administered bright light through glasses immediately after awakening, and wore short-wavelength filter glasses in the evening hours. Treated and untreated patients were comparable in terms of demographics, disease severity/comorbidity, diurnal preference and pre-admission sleep quality/timing. During hospitalization, sleep diaries documented a trend for a lower number of night awakenings in treated compared to untreated patients (1.6 ± 0.8 vs. 2.4 ± 1.3, p = 0.057). Actigraphy documented significantly earlier day mode in treated compared to untreated patients (06:39 ± 00:35 vs. 07:44 ± 00:40, p = 0.008). Sleepiness during a standard day of hospitalization, recorded between 09:30 and 21:30, showed physiological variation in treated compared to untreated patients, who exhibited a more blunted profile. The level of sleepiness reported by treated patients was lower over the 09:30-14:30 interval, i.e., soon after light administration (interaction effect: F = 2.661; p = 0.026). Mood levels were generally higher in treated patients, with statistically significant differences over the 09:30-14:30 time interval, i.e., soon after light administration (treatment: F = 5.692, p = 0.026). In conclusion, treatment with morning bright light and short-wavelength filter glasses in the evening, which was well tolerated, showed positive results in terms of sleepiness/mood over the morning hours and a trend for decreased night awakenings.

Sleep, Circadian Rhythmicity and Response to Chronotherapy in University Students: Tips from Chronobiology Practicals

“…Treatment was well tolerated, none of the students reported any side effects, and sleep onset latency decreased significantly. This, considering that the course of treatment was very short and no control whatsoever exercised on compliance, is impressive, especially by comparison with results we have previously obtained in patients [42,43]. Of course, in this instance we treated young healthy adults of an age when: i) the retinalhypothalamic-pineal tract is expected to be unimpaired in anatomy and physiology; ii) features of delayed sleep phase disorder are still fairly common, especially in males, and iii) poor light-dark hygiene is also common, in relation to the widespread use of light emitting devices such as computers, tablets and smart-phones in the evening and night hours.…”

“…Of great interest, promising results were obtained from a short, locally-developed chronotherapy protocol, based on the combination of light administration in the morning and shading in the evening, which we have previously tested in a pilot study of patients with hospitalisation-related insomnia [ 42 ]. Treatment was well tolerated, none of the students reported any side effects, and sleep onset latency decreased significantly.…”

“…• The Horne-Östberg (HÖ) questionnaire, which defines chronotype as definitely morning (score 70-86), moderately morning (59-69), intermediate (42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58), moderately evening (31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41), and definitely evening (16-30) based on 19 self-administered questions aimed at identifying preferred time of day for carrying out certain activities [24,25].…”

Biological Rhythms, Disorders and their Energetic : A Review

“…Advanced nap stage syndrome: Early to bed and early to wake condition is more frequent in the elderly, and it may be treated with bright light in the evening and light-blocking eyewear in the morning [25].…”

Current and Future Perspectives on Light Therapy Using Wearable Devices

“…Users are recommended to wear these glasses before bedtime. Treatment with morning bright light and shortwavelength filter glasses in the evening improves sleepiness, morning mood, and night awakenings [58]. Light avoidance during evening is associated with increased total sleep time [59].…”