Relationships Among Pupil Responses to Light, Circadian Rhythms, and Sleep (SCOPE)

September 4, 2026 updated by: Elizabeth B Klerman MD PhD

Documenting Relationships Among Pupil Responses to Light, Circadian Rhythms, and Sleep in Healthy People and Those With Disorders or Disease

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.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

100

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Elizabeth Klerman, MD PhD
  • Phone Number: 617-643-2424
  • Email: MGB_OSCAR@mgb.org

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • 18-85 years old.
  • stable medically
  • ability to speak, understand and read English at a high school level

Exclusion Criteria:

  • 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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Lighting intervention
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
One night of dim light exposure and one night of bright light exposure. Lighting from the portable light box

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Pupil size
Time Frame: 1 hour of pupillometry
Pupil size (mm) in response to pupillometry light stimuli using a pupillometry machine
1 hour of pupillometry

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Dim Light Melatonin Onset (DLMO) from saliva
Time Frame: 8 hours
Dim Light Melatonin Onset (DLMO) calculated from salivary melatonin collected during night of ocular dim light exposure
8 hours

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Melatonin suppression
Time Frame: 8 hours on Night 1 (ocular dim light exposure) and 8 hours on Night 2 (ocular bright light exposure)
Melatonin concentration Area Under the Curve (AUC) on Night2/Night1
8 hours on Night 1 (ocular dim light exposure) and 8 hours on Night 2 (ocular bright light exposure)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Elizabeth B Klerman MD PhD

Collaborators

Massachusetts General Hospital

Investigators

  • Principal Investigator: Elizabeth Klerman, MD PhD, MGB

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

September 1, 2027

Primary Completion (Estimated)

December 1, 2034

Study Completion (Estimated)

December 1, 2035

Study Registration Dates

First Submitted

March 17, 2026

First Submitted That Met QC Criteria

August 6, 2026

First Posted (Actual)

August 10, 2026

Study Record Updates

Last Update Posted (Actual)

September 8, 2026

Last Update Submitted That Met QC Criteria

September 4, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • 2025P002861

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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