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

NCT05829044 | Recruiting

• 1 other identifier: 2023P000904
• Study Type: interventional
• Target: 48
• Locations: 1 country
• Sites: 1

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

Keywords

eye pupil response; circadian rhythms; light; melatonin

Outcome Measures

Primary Outcomes (3)

• Pupil size

  Pupil size as measured by pupillometry

  During pupillometry testing on Day 1 afternoon, Day 1 evening, Day 2 morning, Day 2 evening

• Melatonin levels for circadian timing assessment

  Melatonin levels from saliva collection during Night 1 light box red light exposure

  Night 1

• Melatonin levels for hormone response

  Melatonin levels from saliva collection during Night 2 light box blue/green light exposure compared to those during Night 1 light box red light exposure

  Night 1 and Night 2

Study Arms (1)

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

EXPERIMENTAL

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

Device: Pupillometry; Device: Light box exposure

Interventions

Pupillometry DEVICE

Pupillometer measurement of pupil size in response to different light stimuli

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

Light box exposure 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)

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

Eligibility Criteria

• Age: 18 Years - 85 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• (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

You may not qualify if:

• (i) Color blind by Ishihara Color Blindness Test;
• (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

Sponsors & Collaborators

• Massachusetts General Hospital: lead

Study Sites (1)

Massachusetts General Hospital

Boston, Massachusetts, 02114, United States

RECRUITING

Study Officials

• Elizabeth B Klerman, MD PhD

  Massachusetts General Hospital

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Elizabeth B Klerman, MD PhD

CONTACT

617-643-2424; ebklerman@mgh.harvard.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Model Details: All participants will have the same study conditions and schedule except for the order combinations of light stimuli within the pupillometer testing. There are 8 different order combinations of light stimuli. Participants will be randomized to one of those combinations.

Study Record Dates

• First Submitted: April 2, 2023
• First Posted: April 25, 2023
• Study Start: December 1, 2023
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): June 30, 2026
• Last Updated: April 27, 2025

Record last verified: 2025-04

Data Sharing

• IPD Sharing: Will share

Locations

US (1)