Macular Pigment and Glare Disability

University of Georgia109 enrolled

Overview

The purpose of this study is: I. To measure MP optical density (MPOD) in two groups (experimental and placebo) of 50 subjects each (N = 100), during an Lutein + Zeaxanthin supplementation period of 12 months. II. To test the hypothesis that increases in MP (via 12 mg daily Lutein + Zeaxanthin supplementation) will result in significantly improved visual performance under disability glare conditions. III. To test the hypothesis that increases in MP (via 12 mg daily L + Z supplementation) will result in significantly reduced photostress recovery times. IV. To test the hypothesis that increases in MP (via 12 mg daily L + Z supplementation) will result in improved contrast enhancement.

The following measurements will be taken, before and after supplementation with lutein and zeaxanthin: Macular pigment optical density (MPOD) Visual performance under glare conditions Photostress recovery times chromatic contrast sensitivity.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

QUADRUPLE

Enrollment

109

Conditions

Vision, Entoptic

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 40 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Gender: male or female * Age: 18 - 40 years * BMI: 20-30 * No anticipated changes in dieting habits (as relevant to xanthophyll intake). * No anticipated surgical procedures. * Assessed as healthy, based on a pre-study examination including medical history, physical examination, and clinical laboratory. The examination will be performed by an MD or a Nurse Practitioner. * Willingness and ability to give written informed consent and willingness and ability to comply with the study requirements. * Corrected visual acuity (ETDRS): better than 20/60 Exclusion Criteria: * BMI \<20 or \>30 * Age \<18 or \>40 years * Smokers * Current or history of relevant diseases (such as AMD) * Corrected visual acuity worse than 20/60 * Inability to reliably perform MPOD measurements by heterochromatic flicker photometry or any of the other ophthalmic tests of the study. * Any condition likely to interfere with normal gastro-intestinal absorption of xanthophylls. * Current use of xanthophyll containing supplements * Use of xanthophyll containing supplements in the past 6 months * Participation in any other study during last 1 month. * Blood donation during the last 3 months. * Known hypersensitivity or allergy to xanthophylls. * Regular intake of medications or supplements, which the principal investigator deems likely to confound the study outcomes. * Suspected lack of compliance with any requirements of the study. * Childbearing potential and unwillingness to refrain from acceptable anticonceptive measures (not including abstinence). * Current pregnancy or breast feeding * Any relevant abnormalities in the routine laboratory tests

Outcomes

Primary Outcomes

Macular Pigment Optical Density

optical density of macular pigment layer of the neural retina at 30-minutes of retinal eccentricity

Time frame: every three months for one year; 12-month measure reported.

Secondary Outcomes

Glare Disability

light energy needed to obscure or veil a visual target; calculated as log-relative energy, which is the physical energy needed for the subject to report that the visual target has been veiled, given the intensity of the target, logged.

Time frame: 12-month data point only

Photostress Recovery Time

amount of time needed to recover from exposure to a bright light, and to regain sight of a visual target

Time frame: improvement in recovery time; baseline recovery time (sec) minus 12-month recovery time (sec)

Heterochromatic Contrast Sensitivity

amount of short-wave light energy necessary to obscure of veil a visual target, calculated as log-relative energy, which is the physical energy needed for the subject to report that the visual target has been veiled, given the intensity of the target, logged.