EmmetropiaNCT05852782
Effects of Light on the Choroid and Pupil
A study testing White Light therapy, Blue light therapy and Red light therapy in people with Emmetropia and Myopia, run by University of Houston at 1 site in United States.
Trial summary
Monochromatic light creates longitudinal chromatic aberration, with short wavelength blue light forming a focal point in front of the retina and long wavelength red light forming a focal point behind the retina. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Emmetropia, Myopia
- What is being tested?
- White Light therapy, Blue light therapy and Red light therapy
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Feb 2019to 2 Feb 2020
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- ages 18-64
- must be able to comply with the experimental protocol, including collecting saliva and being present for the experiment in the lab on four separate occasions.
- must be willing to abstain from the use of sleep aids 12 hours prior to and for the duration of the study.
- must also be willing to abstain from alcohol and caffeinated beverages (coffee, espresso, energy drinks) or foods enriched with caffeine, such as power bars, the morning of and during each of the four experimental sessions.
Who cannot join
- age < 18 or >64 years old
- not willing to collect a saliva sample or be present in the lab on four separate occasions.
- ocular disease that may affect retinal light levels and function (e.g. glaucoma, significant cataract, etc.)
- use of prescription or over-the-counter medications known to affect sleep and cortisol levels.
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Houston College of Optometry
Houston, Texas, 77004
About this study
Official title: Effects of Narrowband and Broadband Light on Choroidal Thickness and Melanopsin-driven Pupil Response
Monochromatic light creates longitudinal chromatic aberration, with short wavelength blue light forming a focal point in front of the retina and long wavelength red light forming a focal point behind the retina. The investigators hypothesize that such chromatic aberrations, induced by exposure to red or blue LED lights, will cause the choroid behind the retina to respond to bring the image into focus by modulating its thickness, either thickening in the case of blue light or thinning in the case of red light. The magnitude and direction of this response is difficult to predict as previous studies have shown opposite findings in non-human primates and rodents. Furthermore, the investigators hypothesize that exposure to red or blue light will induce changes in how the pupil responds to light, because the cells in the eye that are involved in pupil control are most sensitive to blue light.
Read the detailed description
Ambient light exposure is associated with choroid thickness and eye growth. The spectral composition of light, which has been shown to play a role in eye growth, can differentially regulate changes in choroid thickness by forming a focal point either in front of the retina in the case of short wavelength blue light or behind the retina in the case of long wavelength red light. In addition, melatonin suppression and the pupil light response, specifically, that driven by the intrinsically photosensitive retinal ganglion cells (ipRGCs), are most sensitive to short wavelength blue light. Therefore, the role of the wavelength of light on eye growth may involve ipRGC activity. As such, it is relevant to determine whether exposure to monochromatic light will alter choroidal thickness, ipRGC activity and melatonin levels.
The purpose of this study is to compare the short-term changes in choroid thickness, melatonin concentration, and the ipRGC-driven pupillary light response following one hour of light therapy with either short wavelength blue light or long wavelength red light. It has previously been shown that a one week period of daily morning light therapy produces a short term increase in choroid thickness throughout the day. Therefore, the investigators hypothesize that one hour of morning light therapy with short wavelength blue light will result in different effects in the changes in choroid thickness, melatonin levels, and the ipRGC-driven pupillary light response compared to one hour of morning light therapy with long wavelength red light.
- Conditions
- Emmetropia, Myopia
- Being tested
- White Light therapy, Blue light therapy, Red light therapy, Darkness
- Medical subject headings
- Myopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
White Light therapyOther
Participants will be exposed to broadband light for one hour
Blue light therapyOther
Participants will be exposed to blue light for one hour
Red light therapyOther
Participants will be exposed to re light for one hour
DarknessOther
Participants will be in complete darkness for one hour
| Study group | Role | What they receive |
|---|---|---|
| Light exposure broadband | Experimental | Participants will be exposed to indoor levels of light that appear colorless for one hour Receives: Other: White Light therapy |
| Light exposure long wavelength | Experimental | Participants will be exposed to indoor levels of light that appear red for one hour Receives: Other: Red light therapy |
| Light exposure short wavelength | Experimental | Participants will be exposed to indoor levels of light that appear blue for one hour Receives: Other: Blue light therapy |
| Light exposure darkness | Experimental | Participants will be exposed to darkness for one hour Receives: Other: Darkness |
What is being measured
The primary outcome is the main question the study is designed to answer.
Choroidal Thickness
The choroid will be imaged with OCT to determine choroidal thickness
Measured: one hour
Pupil response
The pupil response will be measured before and after one hour to see if exposure to light affects the diameter
Measured: one hour
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 May 2023
- Study start1 Feb 2019
- Primary completion31 Dec 2019
- Study completion2 Feb 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for EmmetropiaStudies of the same condition, open and under way.
- 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
- Randomised
- Intervention model
- Crossover
- Model description
- All subjects will participate in four conditions on separate days
- Masking
- None (open label)
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Houston
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05852782
- Sponsor's protocol ID
- STUDY00001524
- Status last verified
- Jan 2019
- First submitted
- 27 Apr 2023
- Last updated
- 10 May 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Lou L, Ostrin LA. Effects of Narrowband Light on Choroidal Thickness and the Pupil. Invest Ophthalmol Vis Sci. 2020 Aug 3;61(10):40. doi: 10.1167/iovs.61.10.40.
PubMed 32832970
Study at a glance
From the registry record, last updated by the sponsor on 10 May 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Narrowband and Broadband Light on Choroidal Thickness and Melanopsin-driven Pupil Response
- ClinicalTrials.gov ID
- NCT05852782
- Acronym / sponsor ID
- STUDY00001524
- Conditions
- Emmetropia, Myopia
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- University of HoustonUniversity, hospital or other
- Study start
- 1 Feb 2019 (actual)
- Primary completion
- 31 Dec 2019 (actual)
- Study completion
- 2 Feb 2020 (actual)
- First posted
- 10 May 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.
Monochromatic light creates longitudinal chromatic aberration, with short wavelength blue light forming a focal point in front of the retina and long wavelength red light forming a focal point behind the retina. The investigators hypothesize that such chromatic aberrations, induced by exposure to red or blue LED lights, will cause the choroid behind the retina to respond to bring the image into focus by modulating its thickness, either thickening in the case of blue light or thinning in the case of red light. The magnitude and direction of this response is difficult to predict as previous studies have shown opposite findings in non-human primates and rodents. Furthermore, the investigators hypothesize that exposure to red or blue light will induce changes in how the pupil responds to light, because the cells in the eye that are involved in pupil control are most sensitive to blue light.
Detailed description
Ambient light exposure is associated with choroid thickness and eye growth. The spectral composition of light, which has been shown to play a role in eye growth, can differentially regulate changes in choroid thickness by forming a focal point either in front of the retina in the case of short wavelength blue light or behind the retina in the case of long wavelength red light. In addition, melatonin suppression and the pupil light response, specifically, that driven by the intrinsically photosensitive retinal ganglion cells (ipRGCs), are most sensitive to short wavelength blue light. Therefore, the role of the wavelength of light on eye growth may involve ipRGC activity. As such, it is relevant to determine whether exposure to monochromatic light will alter choroidal thickness, ipRGC activity and melatonin levels.
The purpose of this study is to compare the short-term changes in choroid thickness, melatonin concentration, and the ipRGC-driven pupillary light response following one hour of light therapy with either short wavelength blue light or long wavelength red light. It has previously been shown that a one week period of daily morning light therapy produces a short term increase in choroid thickness throughout the day. Therefore, the investigators hypothesize that one hour of morning light therapy with short wavelength blue light will result in different effects in the changes in choroid thickness, melatonin levels, and the ipRGC-driven pupillary light response compared to one hour of morning light therapy with long wavelength red light.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 4
- Model description
- All subjects will participate in four conditions on separate days
| Arm | Type | Receives |
|---|---|---|
| Light exposure broadband | Experimental | Other: White Light therapyParticipants will be exposed to indoor levels of light that appear colorless for one hour |
| Light exposure long wavelength | Experimental | Other: Red light therapyParticipants will be exposed to indoor levels of light that appear red for one hour |
| Light exposure short wavelength | Experimental | Other: Blue light therapyParticipants will be exposed to indoor levels of light that appear blue for one hour |
| Light exposure darkness | Experimental | Other: DarknessParticipants will be exposed to darkness for one hour |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- ages 18-64
- must be able to comply with the experimental protocol, including collecting saliva and being present for the experiment in the lab on four separate occasions.
- must be willing to abstain from the use of sleep aids 12 hours prior to and for the duration of the study.
- must also be willing to abstain from alcohol and caffeinated beverages (coffee, espresso, energy drinks) or foods enriched with caffeine, such as power bars, the morning of and during each of the four experimental sessions.
Key exclusion criteria (4 listed)
- age < 18 or >64 years old
- not willing to collect a saliva sample or be present in the lab on four separate occasions.
- ocular disease that may affect retinal light levels and function (e.g. glaucoma, significant cataract, etc.)
- use of prescription or over-the-counter medications known to affect sleep and cortisol levels.
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 |
|---|---|---|
| White Light therapyParticipants will be exposed to broadband light for one hour | Other | Light exposure broadband |
| Blue light therapyParticipants will be exposed to blue light for one hour | Other | Light exposure short wavelength |
| Red light therapyParticipants will be exposed to re light for one hour | Other | Light exposure long wavelength |
| DarknessParticipants will be in complete darkness for one hour | Other | Light exposure darkness |
Primary outcome
Choroidal Thickness
Time frame: one hour
The choroid will be imaged with OCT to determine choroidal thickness
Pupil response
Time frame: one hour
The pupil response will be measured before and after one hour to see if exposure to light affects the diameter
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 May 2023.
- Results publication: PubMed 32832970Lou L, Ostrin LA. Effects of Narrowband Light on Choroidal Thickness and the Pupil. Invest Ophthalmol Vis Sci. 2020 Aug 3;61(10):40. doi: 10.1167/iovs.61.10.40.
- published manuscriptLink provided by the sponsor.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing White Light therapy, Blue light therapy and Red light therapy in people with Emmetropia and Myopia, run by University of Houston 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 4 inclusion and 4 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: finished, as of the sponsor's last update on 10 May 2023. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Choroidal Thickness (time frame: one hour). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05852782, which also lists 1 linked publication.
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 10 May 2023.