NCT07753889 · Elizabeth B Klerman MD PhD
Relationships Among Pupil Responses to Light, Circadian Rhythms, and Sleep
(SCOPE)
What this study is about
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.
View original scientific description
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.
Interventions
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
Primary outcome measures
Pupil size
Time frame: 1 hour of pupillometry
Pupil size (mm) in response to pupillometry light stimuli using a pupillometry machine
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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.
Where
- Boston, Massachusetts
Collaborators
Massachusetts General Hospital
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Aug 10, 2026 · Source of record for eligibility and locations