Carotenoid Supplementation and Normal Ocular Health

The Bioavailability of Retinal Carotenoids in the Older Human Eye and Their Effects on Photoreceptor Performance

Normal ageing affects vision as a result of preretinal and retinal changes. Photoreceptors, the light sensitive cells in the retina, degenerate and the rods (responsible for night vision) are most susceptible to damage with increasing age. Rod loss leads to poor vision in the dark which increases the risk of accidents amongst the elderly. Macular pigment (located in the photoreceptors)is thought to protect the retina and reduce the risk of age related changes. Dark adaptation, mediated by the rods, slows down with age, and is also reduced in AMD (age-related macular degeneration). Recent evidence suggests that lutein (the main component of macular pigment) supplementation improves the dark adaptation deficit in AMD subjects. Research into the effects of lutein in a normal human has not been previously conducted. Since the older population is increasing, our aim is to firstly establish the extent of night vision loss (using dark adaptometry) and secondly to examine the possibility of slowing down or reversing this loss through lutein supplementation.

Study Overview

• Status: Completed
• Conditions: Retinal Ageing
• Intervention / Treatment: Dietary supplement: Placebo; Dietary supplement: VisionAce

Detailed Description

It is believed that the macular pigment protects the retina against photooxidative damage which can lead to agerelated macular degeneration (AMD). It is also hypothesized to enhance visual performance in normal human eyes. Much of the research into lutein supplementation has been centered around AMD subjects. AMD can result from agerelated retinal photoreceptor dysfunction which could hypothetically be prevented or slowed down through early supplementation. To our knowledge, the effects of lutein in normal ageing, have not been studied previously.

Macular pigment is composed of lutein and zeaxanthin. These compounds absorb blue light and therefore protect the retinal photoreceptors. They also possess powerful antioxidant properties and therefore help maintain the integrity of the macular region. With increasing age, the visual performance worsens as a result of preretinal and retinal changes such as photoreceptor degeneration. Rods (responsible for night vision) are highly susceptible to degeneration in a normal aging eye and in AMD. Older subjects often complain of reduced vision in the dark which can contribute to increased risk of road traffic accidents and falls. Since the older population is rapidly growing, it is vital to study the mechanics of photoreceptor degeneration and the possible beneficial effects of supplementation with retinal carotenoids, particularly lutein.

The supplement that will be used in this study will be the commercially available Visionace Plus (details attached). The manufacturer of Visionace Plus is Vitabiotics. The placebo will be soya-based, also manufactured by Vitabiotics.

• Study Type: Interventional
• Enrollment (Actual): 88
• Phase: Phase 2; Phase 3

Contacts and Locations

Study Locations

• United Kingdom
  • Manchester, United Kingdom, M13 9PL
    • University of Manchester

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years to 90 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Not on food supplements containing lutein or zeaxanthin
2. Visual acuity at least 0.4 logMAR units (6/15 Snellen)

4. Body mass index of less than 35 5. No diagnosed ocular disease (e.g. established AMD, cataract, glaucoma) 6. Age between 50 and 90

Exclusion Criteria:

1. Diabetes
2. Any diagnosed ocular disease (e.g. AMD, cataract, glaucoma)
3. Under 50 and over 90 years old

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Active lutein group; 44 participants taking VisionAce daily for a period of 1 year	Dietary supplement: VisionAce
Placebo Comparator: Placebo group; 44 participants taking placebo daily for a period of 1 year	Dietary supplement: Placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Changes in macular pigment optical density	12 months
Changes in serum lutein	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in visual performance	The following parameters of visual function will be assessed: Visual acuity Contrast Sensitivity Resolution limit Dark adaptation	12 months

Collaborators and Investigators

• Sponsor: University of Manchester
• Investigators: Study Director: Ian Murray, University of Manchester

Study record dates

Study Major Dates

• Study Start: November 1, 2011
• Primary Completion (Actual): April 1, 2014
• Study Completion (Actual): April 1, 2014

Study Registration Dates

• First Submitted: April 16, 2014
• First Submitted That Met QC Criteria: May 21, 2014
• First Posted (Estimate): May 26, 2014

Study Record Updates

• Last Update Posted (Estimate): May 26, 2014
• Last Update Submitted That Met QC Criteria: May 21, 2014
• Last Verified: April 1, 2014

More Information

Terms related to this study

• Keywords: Retinal ageing, macular pigment, visual function
• Other Study ID Numbers: BB/F017227/1

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No