Impact of Sex and Age on Non-visual Light Input That Affects Sleep and Circadian Rhythms

NCT ID: NCT05829044

Last Updated: 2025-04-27

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 48 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-12-01
• Study Completion Date: 2026-06-30

Brief Summary

The goal of this clinical trial is to learn how the pupil responds to different light stimuli and how that relates to sleep and daily rhythms in healthy people of different ages.

The main questions it aims to answer are:

• Does the eye's pupil response to light stimuli differ by the sex and age of the participant?
• Is the eye's pupil response to light stimuli related to each participant's sleep timing, their body clock timing, and their hormone responses to light.

Participants will have a special eye exam and complete questionnaires before starting the study to see if they can participate. If they can participate, they will wear a special watch that monitors their activity and light levels for one week. Then they will live in a research room at the Mass General Hospital for 3 days/2 nights during which we will test their pupil response to light, their body clock timing, and their hormone responses to light.

Conditions

Normal Physiology

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Testing non-visual light impacts on pupil response, circadian timing, and hormones

1. Pupillometry on day 1 in afternoon and evening and on day 2 in morning and evening. Participants will be randomized to one of 8 different light stimuli within the pupillometry

2. Red light exposure on night 1 to determine circadian timing

3. Blue/green light exposure on night 2 to compare hormone response during blue/green light to that during red light on night 1

Group Type: EXPERIMENTAL

Pupillometry

Intervention Type: DEVICE

Pupillometer measurement of pupil size in response to different light stimuli

Light box exposure

Intervention Type: DEVICE

Using a light box to produce different wavelengths and intensities of light. Exposure to red light on Night 1 and blue/green light on Night 2 to determine circadian timing and suppression of hormone (melatonin)

Interventions

Pupillometry

Pupillometer measurement of pupil size in response to different light stimuli

Intervention Type: DEVICE

Light box exposure

Using a light box to produce different wavelengths and intensities of light. Exposure to red light on Night 1 and blue/green light on Night 2 to determine circadian timing and suppression of hormone (melatonin)

Intervention Type: DEVICE

Eligibility Criteria

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

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 85 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Massachusetts General Hospital

OTHER

Sponsor Role: lead

Responsible Party

Elizabeth B Klerman MD PhD

Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Elizabeth B Klerman, MD PhD

Role: PRINCIPAL_INVESTIGATOR

Massachusetts General Hospital

Locations

Massachusetts General Hospital

Boston, Massachusetts, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Elizabeth B Klerman, MD PhD

Role: CONTACT

ebklerman@mgh.harvard.edu

617-643-2424

Facility Contacts

Elizabeth Klerman, MD PhD

Role: primary

mgh_pulsar_study@mgb.org

857-507-0765

Other Identifiers

2023P000904

Identifier Type: -

Identifier Source: org_study_id