CompletedNot Applicable

Impact of Red Light Therapy on Alleviating Visual Fatigue in Presbyopes

Hong Kong66 participantsStarted 2025-02-10

Plain-language summary

Visual fatigue, or asthenopia, occurs when visual demands exceed the capacity of the visual system, leading to various ocular discomfort and systemic symptoms. This condition can negatively affect personal activities, quality of life, and work productivity. Given the high prevalence of asthenopia in presbyopic population, finding effective methods to alleviate these symptoms is crucial. This study aims to evaluate the effects of repeated low-level red-light (RLRL) therapy on alleviating visual fatigue in individuals with presbyopia over a one-month period. Additionally, we will assess the potential benefits on accommodation function, cognition, and emotional effects of RLRL in this population. Interested individuals will be invited to the PolyU Optometry Clinic to undergo an eligibility examination. An estimated sample size of 66 participants will be recruited. The inclusion criteria specify individuals aged 40 years or older who self-report visual fatigue symptoms and require near correction in daily life. Exclusion criteria include those with ocular disease, systemic diseases, illiteracy, or an afterimage duration longer than 6 minutes. Eligible participants will be randomly assigned in a 1:1 ratio to either the intervention group or the control group. Each participant in the intervention group will be provided an RLRL therapy device, which they are required to use twice daily for 3 minutes per session, with a minimum interval of 4 hours between sessions, 7 days a week for one month. Participants in the control group will receive a sham device, following the same usage schedule. The study will evaluate changes in asthenopia questionnaire scores, CFF scores, other objective asthenopia indicators (i.e., eye movement, pupil parameters, and blink patterns), accommodation function, cognitive function, and emotional states at 2 weeks and 1 month compared to baseline. Statistical analysis will be conducted to explore evaluate within-subject changes over time and between-group differences in visual fatigue metrics, accommodation metrics, cognitive metrics, and emotional metrics. The findings will contribute to evaluating the effectiveness of RLRL therapy in reducing asthenopia and presbyopia symptoms, as well as its impact on cognitive function and emotional well-being.

Who can participate

Age range

40 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Individuals aged over 40 years old. * Self-reported visual fatigue symptoms. * Distance best-corrected visual acuity (BCVA) of 0.5 LogMAR or better, and near visual acuity worse than N8 (20/50) at 40 cm with the subject's habitual distance correction. * Require near correction in daily life. * No light therapy received in the past six months. * Giving informed written consent. Exclusion Criteria: * Presence of diseases that can cause eye pain or headaches, such as strabismus, glaucoma, ocular trauma, conjunctivitis, migraines, keratitis, iridocyclitis, or other self-reported diseases. * Systemic diseases (e.g., epilepsy, photosensitivity, seizure) or illiteracy. * Afterimage time longer than 6 minutes.

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1This trial used red light therapy for visual fatigue in people with presbyopia — is this type of treatment something that's been studied enough for my doctor to feel confident about its safety for my eyes?
2The trial measured changes in asthenopia questionnaire scores, which tracks symptoms like eye strain and fatigue — how meaningful is that kind of outcome compared to actual improvements in my vision or daily functioning?
3Since this trial is already completed, would my doctor be able to share or look up the results, and would those results change any recommendations for how I currently manage my visual fatigue?
4Red light therapy is delivered directly to the eyes — are there any known risks to the retina or other eye structures that I should weigh before considering this type of approach?
5Given that this was a Phase NA study — meaning it may not have followed the usual phase-by-phase safety and efficacy testing path — how much confidence can my doctor have in these findings compared to more conventionally tested treatments for presbyopia-related eye strain?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

change in the asthenopia questionnaire scores

Timeframe: at 2 weeks and 1 month compared to baseline

Trial details

NCT IDNCT06745661

SponsorThe Hong Kong Polytechnic University

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2025-05-23

View on ClinicalTrials.gov More Asthenopia trials