Effects of Light on the Choroid and Pupil

NCT05852782 | Completed

• 1 other identifier: STUDY00001524
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief 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. 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.

Conditions

Emmetropia; Myopia

Outcome Measures

Primary Outcomes (2)

• Choroidal Thickness

  The choroid will be imaged with OCT to determine choroidal thickness

  one hour

• Pupil response

  The pupil response will be measured before and after one hour to see if exposure to light affects the diameter

  one hour

Study Arms (4)

Light exposure broadband

EXPERIMENTAL

Participants will be exposed to indoor levels of light that appear colorless for one hour

Other: White Light therapy

Light exposure long wavelength

EXPERIMENTAL

Participants will be exposed to indoor levels of light that appear red for one hour

Other: Red light therapy

Light exposure short wavelength

EXPERIMENTAL

Participants will be exposed to indoor levels of light that appear blue for one hour

Other: Blue light therapy

Light exposure darkness

EXPERIMENTAL

Participants will be exposed to darkness for one hour

Other: Darkness

Interventions

White Light therapy OTHER

Participants will be exposed to broadband light for one hour

Light exposure broadband

Blue light therapy OTHER

Participants will be exposed to blue light for one hour

Light exposure short wavelength

Red light therapy OTHER

Participants will be exposed to re light for one hour

Light exposure long wavelength

Darkness OTHER

Participants will be in complete darkness for one hour

Light exposure darkness

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• University of Houston: lead

Study Sites (1)

University of Houston College of Optometry

Houston, Texas, 77004, United States

Location

Related Publications (1)

• 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.

  PMID: 32832970 RESULT

Related Links

• published manuscript

MeSH Terms

Conditions

Myopia

Interventions

Phototherapy; Darkness

Condition Hierarchy (Ancestors)

Refractive Errors; Eye Diseases

Intervention Hierarchy (Ancestors)

Therapeutics; Light; Optical Phenomena; Physical Phenomena

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: All subjects will participate in four conditions on separate days

Study Record Dates

• First Submitted: April 27, 2023
• First Posted: May 10, 2023
• Study Start: February 1, 2019
• Primary Completion: December 31, 2019
• Study Completion: February 2, 2020
• Last Updated: May 10, 2023

Record last verified: 2019-01

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)