Relationships Among Pupil Responses to Light, Circadian Rhythms, and Sleep

NCT07753889 | Recruiting

• 1 other identifier: 2025P002861
• Study Type: interventional
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

The investigators are studying relationships among eye pathology, pupil responses to light, sleep, circadian rhythms, and hormones in healthy individuals and those with various medical disorders or illnesses. All participants will:

• Answer questionnaires about their health
• Receive an eye exam,
• For one week at home, participants will track their sleep and wake using actigraphy (wrist worn wearable) and an online sleep diary.
• Complete a pupillometry session (measuring pupil size in response to different lighting) at MGH Participants may also choose to participate in the following additional procedures in any order:
• Within one week of their pupillometry session, an at-home saliva collection under dim light. Saliva melatonin can be analyzed to determine Dim-Light-Melatonin-Onset (DLMO), a marker of circadian timing.
• If participants participate in one night saliva collection, a second night of at-home saliva collection with a bright light exposure to calculate melatonin suppression in response to light.

Conditions

Circadian Rhythm; Pupillometry; Sleep

Keywords

Pupil (eye); Light; Circadian Rhythms; Sleep

Outcome Measures

Primary Outcomes (1)

• Pupil size

  Pupil size (mm) in response to pupillometry light stimuli using a pupillometry machine

  1 hour of pupillometry

Secondary Outcomes (1)

• Dim Light Melatonin Onset (DLMO) from saliva

  8 hours

Other Outcomes (1)

• Melatonin suppression

  8 hours on Night 1 (ocular dim light exposure) and 8 hours on Night 2 (ocular bright light exposure)

Study Arms (1)

Lighting intervention

EXPERIMENTAL

Pupillometry at MGH following by saliva collection during one night of dim light and then one night of bright light

Other: Ocular light exposure from portable light box

Interventions

Ocular light exposure from portable light box OTHER

One night of dim light exposure and one night of bright light exposure. Lighting from the portable light box

Lighting intervention

Eligibility Criteria

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

You may qualify if:

• years old.
• stable medically
• ability to speak, understand and read English at a high school level

You may not qualify if:

• any history of eye trauma or surgery besides correctable vision abnormalities (e.g., with glasses); any abnormalities on clinical eye exam (e.g., neuritis, Neuromyelitis optica, untreated glaucoma) such that the ophthalmologist recommends the participant not be studied;
• 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\\
• shift- or night-work in past three months;
• crossing more than 2 time zones in past three months;
• pregnant or less than 6 months post-partum or breastfeeding.

Sponsors & Collaborators

• Elizabeth B Klerman MD PhD: lead
• Massachusetts General Hospital: collaborator

Study Sites (1)

MassGeneralBrigham

Boston, Massachusetts, 02114, United States

RECRUITING

Study Officials

• Elizabeth Klerman, MD PhD

  MGB

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Elizabeth Klerman, MD PhD

CONTACT

617-643-2424; MGB_OSCAR@mgb.org

Study Design

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

Study Record Dates

• First Submitted: March 17, 2026
• First Posted: August 10, 2026
• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): December 1, 2034
• Study Completion (Estimated): December 1, 2035
• Last Updated: August 10, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)