Actively Recruiting
Altered Non-Visual Photoreception in Patients With Glaucoma: Impacts on Sleep, Alertness, Mood, and Cognition
Led by National University of Singapore · Updated on 2026-01-23
120
Participants Needed
2
Research Sites
8 weeks
Total Duration
On this page
Sponsors
N
National University of Singapore
Lead Sponsor
S
Singapore National Eye Centre
Collaborating Sponsor
AI-Summary
What this Trial Is About
This research aims to understand how light sensitivity in the eye influences sleep, mood, alertness, and thinking skills in adults with glaucoma compared to healthy individuals aged 45 to 75 years. It explores whether people with glaucoma have poorer sleep and mood due to damage to special retinal cells called intrinsically photosensitive retinal ganglion cells (ipRGCs) and whether exposure to safe, full-spectrum indoor light can improve these functions. Participants include 60 patients with primary open-angle glaucoma and 60 healthy adults matched by age. Each participant undergoes two laboratory visits: the first includes eye exams and questionnaires about sleep, mood, and cognition. They then wear a wrist device for 8 to 16 days to track sleep and light exposure. The second visit involves exposure to two types of light conditions—standard indoor light (~300 lux) and full-spectrum white light (~1000 lux)—in a randomized crossover design, followed by cognitive and attention tests with eye tracking. During the study, participants complete various cognitive tasks and mood assessments before and after light exposure sessions. Researchers measure sleep quality, alertness, mood, cognitive function, pupil responses, and risk-taking behavior. The study monitors changes over time and between light conditions to evaluate the impact of glaucoma on brain function beyond vision and the potential benefits of light therapy for wellbeing.
CONDITIONS
Brief Title
Altered Non-Visual Photoreception in Patients With Glaucoma: Impacts on Sleep, Alertness, Mood, and Cognition
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Patients diagnosed with primary open-angle glaucoma with Humphrey Visual Field mean deviation better than -12 dB in at least one eye
- Patients having spared central vision
- Patients aged 45 to 75 years old
- Patients with best-corrected visual acuity better than 6/12
- English-speaking patients
- Healthy controls aged 50 to 70 years old
- Healthy controls with best-corrected visual acuity better than 6/12
- Healthy controls with normal eye exams
- English-speaking healthy controls
You will not qualify if you...
- Participants with myopia worse than -8.00 diopters
- History of complicated previous intraocular surgery
- Use of alpha-adrenergic agonist eye drops or systemic medications affecting pupil response
- Any past or current eye conditions such as age-related macular degeneration, diabetic retinopathy, optic neuropathies, significant trauma, or fixation problems
- Cataracts at NS3+ or Posterior Subcapsular cataracts
- Psychiatric or neurologic disorders including cognitive impairment or dementia
- Diagnosed mood disorders
- Night shift work in past 3 months, current sleeping pill use, or recent travel across time zones
- Obstructive sleep apnea
- Abnormal hearing function
- Impaired color vision
- Pre-menopausal women with last menstrual period less than 1 year ago
- Patients with unilateral glaucoma, congenital glaucoma, non-glaucomatous optic neuropathy, or abnormal central vision
- Diabetics on treatment
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 8 to 16 days
Participants undergo a comprehensive eye examination and complete questionnaires assessing sleep quality, daytime sleepiness, mood, and cognitive function. Non-visual light sensitivity is also measured. Participants are provided with a wrist-worn device to record sleep-wake cycles and light exposure at home.
1 visit (in-person) and home monitoring for 8 to 16 days
Duration - 1 day
Participants attend a laboratory visit where they are exposed to two different lighting conditions in a randomized cross-over design: standard indoor light and full-spectrum white light. Cognitive and attention tests are performed alongside eye tracking and pupillometry to assess alertness, sleepiness, mood, and cognitive function during and after light exposure.
1 visit (in-person) with two sessions of light exposure and cognitive testing
Trial Site Locations
Total: 2 locations
1
National University Hospital
Singapore, Singapore
Not Yet Recruiting
2
Singapore National Eye Center
Singapore, Singapore
Actively Recruiting
Research Team
D
Daniella Mahfoud, MSc.
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
RANDOMIZED
Model
CROSSOVER
Primary Purpose
SUPPORTIVE_CARE
Number of Arms
2
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