An interventional study of Carotenoids supplementation and Placebo in Vision Disorders, sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University. Not yet recruiting. Open to participants aged 35 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-01-23.
Sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University · Not applicable, Interventional, and Supportive care
The macula is a pigmented area at the center of the retina, and responsible for the central, high-resolution color vision. Age-related macular degeneration (AMD) is a disease of the macula and is the leading cause of irreversible vision impairment and blindness worldwide. The yellow pigment at the macula is referred to as macular pigment. There is now strong evidence showing that macular pigment (MP), which is composed of the dietary carotenoids lutein (L), meso-zeaxanthin (MZ), and zeaxanthin (Z) is protective against AMD and vision loss. MP is a powerful antioxidant and also filters short-wavelength (blue) light at the macula. The AREDS2 study concluded that supplementation of L and Z is beneficial for patients with non-advanced age-related macular degeneration (AMD). The CREST and other studies had reported that dietary supplementation of these carotenoids could enhance contrast sensitivity among the Caucasian population, whereas little information is known about the effect of dietary supplementation of carotenoids on contrast sensitivity among Chinese. Thus in this study, we aim to investigate whether supplementation of a formulation containing 10 mg L, 10 mg MZ, and 2mg Z on contrast sensitivity in Chinese subjects free of retinal disease. This study is a single-center, double-blinded, placebo-controlled, randomized clinical trial conducted at Zhongshan Ophthalmic Center (ZOC), Sun Yat-sen University, Guangzhou, China. Participants in the intervention group received oral supplementation of 10 mg L, 10 mg MZ, and 2mg Z in a formula base oil suspension as one soft gel capsule in the morning per day. Participants in the control group receive one soft gel capsule of placebo oil per day. The intervention and placebo supplements are identical in external appearance, and the two treatments are therefore indistinguishable from each other. The duration of the study intervention is 12 months, and study visits are conducted at baseline, 3 months, 6 months, and 12 months. The primary outcome measure is the change in contrast sensitivity (CS) at 6 cycles per degree (cpd) over the study course: Y=CS4-CS1, where CS1 is CS at 6 cpd at baseline, CS4 is the CS at 6cpd at the 12-month follow-up. The secondary outcomes of this study include CS at other cpds and at other study visits, best-corrected visual acuity, subjective visual function, and skin carotenoid levels at each study visit.
360 studies on the registry are indexed under Vision Disorders; 84 are open to participants now.
This study's planned enrollment of 220 is above the median of 78 across 244 interventional studies indexed under Vision Disorders.
Browse Vision Disorders studies →Zhongshan Ophthalmic Center, Sun Yat-sen University is the lead sponsor of 164 studies on the registry; 80 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants in the intervention group receive oral supplementation of 10 mg L, 10 mg MZ and 2mg Z in a formula base oil suspension as one soft gel capsule in the morning per day. Each capsule contains 22 mg of carotenoids (10+10+2mg), thus each participant in the intervention group will receive a total of 22 mg of carotenoids per day.
Dietary Supplement: Carotenoids supplementation
Participants in the control group receive one soft gel capsule of placebo oil per day.
Dietary Supplement: Placebo
Daily oral supplementation of a soft gel capsule containing 10mg lutein (L), 10mg meso-zeaxanthin (MZ) and 2mg zeaxanthin (Z).
Daily oral supplementation of a soft gel capsule containing only placebo oil
Change in contrast sensitivity (CS) at 6 cycles per degree (cpd) over 1 year
CS at 6 cpd at the 12-month follow-up minus CS at 6 cpd at baseline.
Time frame: 1 year
CS at other cpds and at other study visits
CS at 1.2, 2.4, 9.6 and 15.15 cpd at baseline, 3-month follow-up, 6-month follow-up and 12-month follow-up; as well as CS at 6 cpd at 3-month follow-up and 6-month follow-up
Time frame: 1 year
Best-corrected visual acuity
Best-corrected visual acuity at baseline, 3-month follow-up, 6-month follow-up and 12-month follow-up
Time frame: 1 year
Subjective visual function
Subjective visual function measured by questionnaire at baseline, 3-month follow-up, 6-month follow-up and 12-month follow-up
Time frame: 1 year
Skin carotenoids score
Skin carotenoids score at baseline, 3-month follow-up, 6-month follow-up and 12-month follow-up
Time frame: 1 year
No study locations are listed for this record.
Plan to share: No
This study is not yet recruiting, as verified in Jan 2026. You cannot join it, but the record below documents what was studied.
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