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NCT Number: NCT07753889

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

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.

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Key information

Conditions

Circadian Rhythm Pupillometry Sleep

Age range

18 year–85 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

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

Primary outcomes

  1. Pupil size

    Time frame: 1 hour of pupillometry

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

Secondary outcomes

  1. 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

Other outcomes

  1. 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

Study contacts

Contact information is provided by the study sponsor or research team.

Elizabeth Klerman, MD PhD

CONTACT

[email protected]

617-643-2424

Sponsors and collaborators

Lead sponsor

Elizabeth B Klerman MD PhD

Other

Collaborators

  • Massachusetts General Hospital

Registry information

Official study title

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

Acronym: SCOPE

Important dates

Study start
2027
Primary completion
2034
Study completion
2035
First posted
Aug 10, 2026
Registry last updated
Sep 8, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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