Effects of Blue-enriched White Light Therapy in Patients with Fibromyalgia

Fibromyalgia is a chronic condition with an unclear etiology. The syndrome includes symptoms such as chronic musculoskeletal pain, cognitive dysfunctions, fatigue, sleep disorders, and circadian rhythm disturbances. Fibromyalgia-related pain is associated with a substantial socioeconomic burden including greater health care costs and productivity loss from work. Light therapy can improve sleep quality and sleep architecture, advance sleep phases and reduce pain sensitivity and that the effect of light therapy on mood and cognitive function have been widely supported.This randomized controlled study aims to examine the effects of light therapy on sleep quality, depressive symptoms, psychomotor vigilance performance, and overall symptom severity in patients with fibromyalgia.

Fibromyalgia is a central sensitivity syndrome characterized by chronic widespread pain, cognitive dysfunctions, fatigue, sleep disorders, and circadian dysregulation. Light therapy can improve sleep quality and sleep architecture, advance sleep phases and reduce pain sensitivity and that the effect of light therapy on mood and cognitive function have been widely supported, research into the effect of light therapy for patients with fibromyalgia who often suffer from sleep and mood disturbance, pain, and cognitive impairments is of both research interest and therapeutic implications. This study will use a randomized, parallel group, assessor-blind, waiting-list controlled trial design. The primary outcome is symptom severity. The secondary outcomes include: sleep quality; depressive symptoms; psychomotor vigilance and attention; and sleep phase changes. The intervention will take 8 weeks with 30 minutes exposure at awakening to blue-enriched white light. A total of 80 participants, aged 20 to 64, with a diagnosis of fibromyalgia will be enrolled and randomly assigned into one of the two parallel groups: an intervention and a waiting list group. For the intervention group, outcomes will be assessed at baseline, immediately after, and 2 months after the 8-week intervention period. For the waiting list group, outcomes will be assessed at baseline, immediately after the 8-week waiting period, and 2 months after the intervention period.

Eligibility Criteria:
Inclusion Criteria:

1. Participants must be aged from 20 to 64 years old.
2. Participants must read and understand Chinese language.
3. Participants must be outpatients.
4. Participants must have a confirmed diagnosis of fibromyalgia according to the 2016 American College of Rheumatology diagnostic criteria.

Exclusion Criteria:

1. Subjects who are admitted to the hospital.
2. Subjects who have other significant chronic disease, past or present psychosis, or bipolar disorder.
3. Subjects who have ophthalmic pathology (cataract, macular degeneration, glaucoma, retinitis pigmentosa), eye surgery, diseases affecting the retina (retinopathy, diabetes, herpes, etc.), color blind, or taking photosensitizing medications.
4. Subjects who are taking opiates or benzodiazepines.
5. Subjects who work night shifts, or travel across more than two time zones in the month prior to enrolling in the study.
6. Subjects who are pregnant.
7. Subjects who have used light treatment in the last 6 months.