Understanding how light affects sleep and body clocks based on age and sex

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This clinical trial investigates how the pupil's response to light stimuli varies with age and sex, and how these responses relate to sleep patterns and circadian rhythms in healthy individuals. Participants aged 18 to 85 will undergo a special eye exam and complete questionnaires to determine eligibility. Those who qualify will wear a monitoring device for a week and then stay in a research facility for three days to assess their pupil response, body clock timing, and hormonal reactions to light exposure. The study aims to enhance our understanding of the physiological mechanisms underlying sleep and circadian rhythms.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* (i) 18-85 years old.
* (ii) Habitual sleep onset 10 pm- 1 am (healthy controls only);
* (iii) Habitual wake onset 5:30 am- 8:30 am (healthy controls only);
* (iv) vision correctable to 20/30;
* (v) stable medically.
* (vi) ability to speak, understand, and read English at a high school level

Exclusion Criteria:

* (i) Color blind by Ishihara Color Blindness Test;
* (ii) any history of eye trauma, surgery or abnormality (e.g., retinopathy, glaucoma, cataracts, amblyopia, macular degeneration, congenital color vision deficiencies, or any type of blindness) besides correctable vision abnormalities (e.g., with glasses); any abnormalities on clinical eye exam (e.g., neuritis, Neuromyelitis optica, treated or untreated glaucoma) such that the ophthalmologist recommends the participant not be studied; Limited cataracts (e.g., Lens Opacities Classification (LOCS) III grade \<2) will be allowed and documented during the eye exam. Eye drops that affect pupil size or contractility (e.g. mydriatics, miotics); drops to treat glaucoma (e.g., pilocarpine, brimonidine, other drops like artificial tear drops, or anti-inflammatory drops would not be exclusionary)
* (iii) current or history of neurologic or psychiatric disease including autonomic function disorder or migraines; psychiatric disorder requiring medications in a first degree relative (healthy controls only); limited-duration counseling without prescription medications will not be exclusionary; (iv) current or history of circadian rhythm sleep-wake disorder (healthy controls only);
* (v) prescription or non-prescription drugs affecting the pupil (e.g., affecting autonomic function), sleep, melatonin (e.g., lithium, alpha- and beta-adrenergic antagonists), and/or circadian rhythms (e.g., beta blockers, non-steroidal anti-inflammatory drugs, tricyclics);
* (vi) Other disorders that can affect or may be affected by intrinsically photosensitive Retinal Ganglion Cell (ipRGC) function, including diabetes mellitus, multiple sclerosis, Parkinson's disease, seasonal affective disorder;
* (vii) shift- or night-work in past three months; history of night work in preceding 3 year period
* (viii) crossing more than 2 time zones in past three months;
* (ix) presence of depression as assessed by a Beck Depression Inventory (BDI) score \>14.
* (x) pregnant or less than 6 weeks post-partum or breast-feeding

Where it's running

• Massachusetts General Hospital
  Boston, Massachusetts, United States Recruiting

Study contacts

• Principal investigator: Elizabeth B Klerman, MD PhD — Massachusetts General Hospital
• Study coordinator: Elizabeth B Klerman, MD PhD
• Email: ebklerman@mgh.harvard.edu
• Phone: 617-643-2424

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.