Understanding Circadian Responses to Light in Persons With Mild Cognitive Impairment

Understanding Circadian Responses to Light in Persons With Mild Cognitive Impairment and Alzheimer's Disease

The purpose of this research study is to investigate the relationship between light, the thickness of the pigment at the back of your eye, melatonin levels, and memory. The study will investigate whether changing light distribution pattern from "on-axis"' (i.e., directed along the eye's visual axis to the fovea) to "off-axis" (i.e., directed on the periphery of the eye's visual axis) impact melatonin suppression in 24 mild cognitive impairment participants and 24 healthy, age-matched controls.

Study Overview

• Status: Completed
• Conditions: Alzheimer Disease; Mild Cognitive Impairment
• Intervention / Treatment: Device: Lighting Intervention Blue light; Device: Lighting Intervention Green light; Other: Dim-light control condition

Detailed Description

Eligible enrolled subjects will be exposed to 4 different lighting conditions in addition to one dark control condition. There will be 5 study session and each one will last for 90 minutes and will be separated by one week. Subjects will collect 3 saliva samples, each one 30 minutes apart for melatonin levels during each study session.

• Study Type: Interventional
• Enrollment (Actual): 36
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New York
    • Menands, New York, United States, 12204
      • Light and Health Research Center at Mount Sinai

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 55 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• mild cognitive impairment
• age matched healthy control
• macular pigment density either < 0.3 or > 0.5

Exclusion Criteria:

• extensive brain vascular disease
• Parkinson's disease
• bipolar disorder
• seasonal depression
• diabetes
• high blood pressure
• obstructing cataracts
• macular degeneration
• diabetic retinopathy
• use of melatonin supplements
• use of beta blockers
• use of sleep medications
• use of antidepressant medication

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Participants with Mild Cognitive Impairment; Every participant experienced all 5 conditions: Blue light (λmax = 451 nm) on axis and off axis. Green light (λmax = 522 nm) on and off axis Dim-light control condition (< 5 lux at the eye) for 30 min each narrowband source will have distinct lighting distribution patterns but calibrated to deliver the same targeted levels of circadian light (CLA) and circadian stimulus (CS) at the eye.

Device: Lighting Intervention Blue light; Custom made lighting fixture that will deliver the blue lighting intervention. Blue light (λmax = 451 nm) on axis and off axis.; Device: Lighting Intervention Green light; Custom made lighting fixture that will deliver the green lighting intervention. Green light (λmax = 522 nm) on and off axis; Other: Dim-light control condition; (< 5 lux at the eye) for 30 min

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Melatonin Levels	Saliva samples collected for melatonin levels for the different conditions. Blue light (λmax = 451 nm) on axis and off axis: for each narrowband source, designated on-axis or off-axis, will have distinct lighting distribution patterns but calibrated to deliver the same targeted levels of circadian light (CLA) and circadian stimulus (CS) at the eye. Green light (λmax = 522 nm) on and off axis: for each narrowband source, designated on-axis or off-axis, will have distinct lighting distribution patterns but calibrated to deliver the same targeted levels of circadian light (CLA) and circadian stimulus (CS) at the eye. Dim-light control condition: (< 5 lux at the eye) for 30 min	post-intervention (60 minutes) on each night of intervention (one night a week for 5 weeks)

Collaborators and Investigators

• Sponsor: Icahn School of Medicine at Mount Sinai
• Collaborators: National Institute on Aging (NIA)
• Investigators: Principal Investigator: Mariana Figueiro, PhD, Icahn School of Medicine

Study record dates

Study Major Dates

• Study Start (Actual): June 14, 2021
• Primary Completion (Actual): May 31, 2024
• Study Completion (Actual): May 31, 2024

Study Registration Dates

• First Submitted: June 2, 2022
• First Submitted That Met QC Criteria: June 6, 2022
• First Posted (Actual): June 9, 2022

Study Record Updates

• Last Update Posted (Actual): June 24, 2025
• Last Update Submitted That Met QC Criteria: June 5, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Mental Disorders; Neurocognitive Disorders; Cognition Disorders; Dementia; Tauopathies; Neurodegenerative Diseases; Cognitive Dysfunction; Alzheimer Disease
• Other Study ID Numbers: GCO 21-0400; R21AG070713 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No