How glaucoma-related changes in light sensing affect sleep, mood, alertness, and thinking
Altered Non-Visual Photoreception in Patients With Glaucoma: Impacts on Sleep, Alertness, Mood, and Cognition
For adults 45–75 with glaucoma, this study will test whether reduced light sensitivity is linked to worse sleep, mood, alertness, and thinking, and whether safe full‑spectrum indoor light can help.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 120 (estimated) |
| Ages | 45 Years to 75 Years |
| Sex | All |
| Sponsor | National University of Singapore Academic / other |
| Drugs / interventions | radiation |
| Locations | 2 sites (Singapore and 1 other locations) |
| Trial ID | NCT07364929 on ClinicalTrials.gov |
What this trial studies
This mixed observational and interventional study will compare 60 adults with bilateral primary open‑angle glaucoma to 60 age‑matched healthy controls to measure non‑visual responses to light. Participants undergo eye exams, questionnaires, cognitive and alertness tests, and physiological measures of light sensitivity, followed by short exposures to full‑spectrum versus standard indoor lighting. The design aims to link ipRGC‑related light sensitivity to sleep, mood, alertness, and cognitive performance and to test whether altering indoor light improves these outcomes. Outcomes will be compared between groups and within individuals before and after light exposure.
Who should consider this trial
Good fit: Ideal candidates are adults aged 45–75 with bilateral primary open‑angle glaucoma, spared central vision, Humphrey visual field mean deviation better than −12 dB in at least one eye, and best‑corrected visual acuity better than 6/12.
Not a fit: People with very advanced vision loss beyond the study thresholds, major comorbid eye or neurological disorders, or who cannot attend in‑person visits or tolerate light exposure are unlikely to receive benefit from this protocol.
Why it matters
Potential benefit: If successful, the approach could offer a simple, noninvasive way to improve sleep, alertness, mood, and daytime function for people with glaucoma.
How similar studies have performed: Prior work links ipRGC loss to disrupted circadian rhythms and shows light therapy can improve sleep and alertness in other populations, but randomized evidence specifically in glaucoma is limited.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Patients with glaucoma must meet all of the inclusion criteria to participate in this study. * Patients diagnosed with primary open-angle glaucoma (POAG), as indicated by Humphrey Visual Field (HVF) mean deviation (VFMD) scores better than -12 dB in at least one eye during their most recent clinic visit. * Patients having spared central vision. * Patients aged 45 to 75 years old. * Patients with a best-corrected visual acuity better than 6/12 * English-speaking patients Healthy controls must meet all of the inclusion criteria to participate in this study: * Participants aged 50 to 70 years old. * Participants with a best-corrected visual acuity better than 6/12 * Normal ophthalmic examination * English-speaking participants Exclusion Criteria: * All subjects (patients and controls) meeting any of the exclusion criteria at baseline will be excluded from participation: * Participants with myopia exhibiting a refractive error exceeding -8.00 diopters (D) * Participants with a history of complicated previous intraocular surgery * Participants taking alpha-adrenergic agonist eye drops or other systemic medications or drugs that could affect the pupillary response * Participants with any past or current ocular condition (i.e., age-related retinal diseases (e.g., age-related macular degeneration), retinal pigment epithelium diseases (e.g., Best's disease), diabetic retinopathy, or other optic or generalized neuropathies, significant ocular trauma, or any eye condition affecting fixation (eg. Nystagmus)). * Participants diagnosed with cataracts at NS3+ (Nuclear Sclerosis) and above, as well as those with Posterior Subcapsular (PSC) cataracts * Participants with clinically diagnosed psychiatric or neurologic disorders, including cognitive impairment or dementia * Participants with diagnosed mood disorders * Participants engaged in night shift work within the past three months, are currently using sleeping pills, or have recently travelled across timezones within a month prior to the study * Participants with obstructive sleep apnea * Participants with abnormal auditory function * Participants with impaired color vision * Pre-menopausal women (last menstrual period \< 1 year) (If applicable) * Patients having unilateral glaucoma, congenital glaucoma, non-glaucomatous optic neuropathy, abnormal central vision * Diabetics on treatment
Where this trial is running
Singapore and 1 other locations
- National University Hospital — Singapore, Singapore (Not_yet_recruiting)
- Singapore National Eye Center — Singapore, Singapore (Recruiting)
Study contacts
- Principal investigator: Raymond P. Najjar, PhD — National University of Singapore
- Study coordinator: Daniella Mahfoud, MSc.
- Email: daniella.mahfoud@u.nus.edu
- Phone: +65 65165474
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.