Normal PhysiologyNCT05829044
Impact of Sex and Age on Non-visual Light Input That Affects Sleep and Circadian Rhythms
A study testing Pupillometry and Light box exposure in people with Normal Physiology, run by Massachusetts General Hospital at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 85 yearsHealthy volunteers can take part
- Conditions the study is for
- Normal Physiology
- What is being tested?
- Pupillometry and Light box exposure
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 48 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Dec 2023to 30 Jun 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 85 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- (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
Who cannot join
- (i) Color blind by Ishihara Color Blindness Test;
- (ii) any history of eye trauma, surgery or abnormality (e.g., retinopathy, glaucoma, cataracts, amblyopia, macular degeneration, congenital color vision deficiencies, or any type of blindness) besides correctable vision abnormalities (e.g., with glasses); any abnormalities on clinical eye exam (e.g., neuritis, Neuromyelitis optica, treated or untreated glaucoma) such that the ophthalmologist recommends the participant not be studied; Limited cataracts (e.g., Lens Opacities Classification (LOCS) III grade <2) will be allowed and documented during the eye exam. Eye drops that affect pupil size or contractility (e.g. mydriatics, miotics); drops to treat glaucoma (e.g., pilocarpine, brimonidine, other drops like artificial tear drops, or anti-inflammatory drops would not be exclusionary)
- (iii) current or history of neurologic or psychiatric disease including autonomic function disorder or migraines; psychiatric disorder requiring medications in a first degree relative (healthy controls only); limited-duration counseling without prescription medications will not be exclusionary; (iv) current or history of circadian rhythm sleep-wake disorder (healthy controls only);
- (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
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- (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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Massachusetts General Hospital
Boston, Massachusetts, 02114
Elizabeth Klerman, MD PhD, 857-507-0765, mgh_pulsar_study@mgb.org
About this study
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:
Read more
- 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
- Being tested
- Pupillometry, Light box exposure
- Keywords
- eye pupil response, circadian rhythms, light, melatonin
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PupillometryDevice
Pupillometer measurement of pupil size in response to different light stimuli
Light box exposureDevice
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)
| Study group | Role | What they receive |
|---|---|---|
| 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 Receives: Device: Pupillometry; Device: Light box exposure |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pupil size
Pupil size as measured by pupillometry
Measured: 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
Measured: 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
Measured: Night 1 and Night 2
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Apr 2023
- Study start1 Dec 2023
- Primary completion30 Jun 2027 (estimated)
- Study completion30 Jun 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Normal PhysiologyStudies of the same condition, open and under way.
- More trials run by Massachusetts General HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- 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.
- Masking
- None (open label)
- Enrolment
- 48 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Massachusetts General Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Elizabeth B Klerman MD PhD, Massachusetts General Hospital
- Investigators
- Elizabeth B Klerman, MD PhD, Principal investigator, Massachusetts General Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05829044
- Sponsor's protocol ID
- 2023P000904
- Status last verified
- Jul 2026
- First submitted
- 2 Apr 2023
- Last updated
- 13 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Data sharing will be conducted per National Institutes of Health (NIH) and MassGeneralBrigham (MGB) policies and regulations. Only de-identified data will be shared.
Study at a glance
From the registry record, last updated by the sponsor on 13 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of Sex and Age on Non-visual Light Input That Affects Sleep and Circadian Rhythms
- ClinicalTrials.gov ID
- NCT05829044
- Acronym / sponsor ID
- 2023P000904
- Conditions
- Normal Physiology
- Keywords
- eye pupil response, circadian rhythms, light, melatonin
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 48 participants (estimated)
- Lead sponsor
- Massachusetts General HospitalUniversity, hospital or other
- Study start
- 1 Dec 2023 (actual)
- Primary completion
- 30 Jun 2027 (estimated)
- Study completion
- 30 Jun 2027 (estimated)
- First posted
- 25 Apr 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- 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.
| Arm | Type | Receives |
|---|---|---|
| Testing non-visual light impacts on pupil response, circadian timing, and hormones | Experimental | Device: Pupillometry, Device: Light box exposure1. 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 |
Who may qualify
- Ages
- 18 to 85 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- (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.
Key exclusion criteria (9 listed)
- (i) Color blind by Ishihara Color Blindness Test;
- (ii) any history of eye trauma, surgery or abnormality (e.g., retinopathy, glaucoma, cataracts, amblyopia, macular degeneration, congenital color vision deficiencies, or any type of blindness) besides correctable vision abnormalities (e.g., with glasses); any abnormalities on clinical eye exam (e.g., neuritis, Neuromyelitis optica, treated or untreated glaucoma) such that the ophthalmologist recommends the participant not be studied; Limited cataracts (e.g., Lens Opacities Classification (LOCS) III grade <2) will be allowed and documented during the eye exam. Eye drops that affect pupil size or contractility (e.g. mydriatics, miotics); drops to treat glaucoma (e.g., pilocarpine, brimonidine, other drops like artificial tear drops, or anti-inflammatory drops would not be exclusionary)
- (iii) current or history of neurologic or psychiatric disease including autonomic function disorder or migraines; psychiatric disorder requiring medications in a first degree relative (healthy controls only); limited-duration counseling without prescription medications will not be exclusionary; (iv) current or history of circadian rhythm sleep-wake disorder (healthy controls only);
- (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;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PupillometryPupillometer measurement of pupil size in response to different light stimuli | Device | Testing non-visual light impacts on pupil response, circadian timing, and hormones |
| Light box exposureUsing 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) | Device | Testing non-visual light impacts on pupil response, circadian timing, and hormones |
Primary outcome
Pupil size
Time frame: During pupillometry testing on Day 1 afternoon, Day 1 evening, Day 2 morning, Day 2 evening
Pupil size as measured by pupillometry
Melatonin levels for circadian timing assessment
Time frame: Night 1
Melatonin levels from saliva collection during Night 1 light box red light exposure
Melatonin levels for hormone response
Time frame: Night 1 and Night 2
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
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Jul 2026.
- Individual participant dataSharing planned: Yes. Data sharing will be conducted per National Institutes of Health (NIH) and MassGeneralBrigham (MGB) policies and regulations. Only de-identified data will be shared.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Elizabeth B Klerman, MD PhD principal investigator
Massachusetts General Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Pupillometry and Light box exposure in people with Normal Physiology, run by Massachusetts General Hospital at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 13 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Elizabeth B Klerman, MD PhD (617-643-2424, ebklerman@mgh.harvard.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Pupil size (time frame: During pupillometry testing on Day 1 afternoon, Day 1 evening, Day 2 morning, Day 2 evening). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Jul 2026.