[The macular pigment: short- and intermediate-term changes of macular pigment optical density following supplementation with lutein and zeaxanthin and co-antioxidants. The LUNA Study]

[Practical application of ophthalmic nutraceuticals in patients with dry form of age-related macular degeneration]

Development and progression of age-related macular degeneration (AMD) is associated with insufficiency of protective antioxidant systems of the body. Nutraceutical medications can positively affect the course of the disease and the visual functions of patients with AMD.

PURPOSE

To conduct a placebo-controlled clinical monitoring of visual functions in patients with dry AMD while taking a drug Complex that corresponds to the AREDS 2 formula.

MATERIAL AND METHODS

The study included 90 people in 3 equivalent parallel groups, two of which were represented by patients with AMD who took the Complex for 3-6 months or Placebo for 3 months. The third group included healthy subjects of the same age. In addition to standard eye examination, participants underwent evaluation of the macular pigment optical density (MPOD), spatial-frequency contrast sensitivity (CS), photostress test, and reading parameters on the Salzburg Reading Desk device. The changes of blood plasma antioxidant activity (AOA) were also evaluated in the main group.

RESULTS

By day 90 of the study, patients of the main group showed statistically significant (p<0.001) growth of MPOD from 0.24±0.13 to 0.32±0.1, reduction of photostress recovery time from 68.2±17.8 to 57.3±17.5 seconds, improvement of high-spatial-frequency CS - from 25.0±8.2 to 30.6±6.8 dB, increase of near visual acuity logMAR from 0.22±0.04 to 0.19±0.03 and reading speed, and decrease of reading mistakes. Statistically significant (p<0.05) reduction of in AOA was seen during the observation period from 1.52±0.16 to 1.68±0.16. Patients of the main group who received the Complex for 180 days demonstrated additional improvements of visual functions.

CONCLUSION

The drug Complex corresponding to the AREDS 2 formula contributes to a significant increase in MPOD, improvements of visual functions and overall antioxidant status of patients, which confirms the feasibility of its use in patients with dry AMD.

An Evidence-Based Systematic Review of Lutein by the Natural Standard Research Collaboration

An evidence-based systematic review of lutein by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated, reproducible grading rationale. This article includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.

Macular xanthophylls, lipoprotein-related genes, and age-related macular degeneration

Plant-based macular xanthophylls (MXs; lutein and zeaxanthin) and the lutein metabolite meso-zeaxanthin are the major constituents of macular pigment, a compound concentrated in retinal areas that are responsible for fine-feature visual sensation. There is an unmet need to examine the genetics of factors influencing regulatory mechanisms and metabolic fates of these 3 MXs because they are linked to processes implicated in the pathogenesis of age-related macular degeneration (AMD). In this work we provide an overview of evidence supporting a molecular basis for AMD-MX associations as they may relate to DNA sequence variation in AMD- and lipoprotein-related genes. We recognize a number of emerging research opportunities, barriers, knowledge gaps, and tools offering promise for meaningful investigation and inference in the field. Overviews on AMD- and high-density lipoprotein (HDL)-related genes encoding receptors, transporters, and enzymes affecting or affected by MXs are followed with information on localization of products from these genes to retinal cell types manifesting AMD-related pathophysiology. Evidence on the relation of each gene or gene product with retinal MX response to nutrient intake is discussed. This information is followed by a review of results from mechanistic studies testing gene-disease relations. We then present findings on relations of AMD with DNA sequence variants in MX-associated genes. Our conclusion is that AMD-associated DNA variants that influence the actions and metabolic fates of HDL system constituents should be examined further for concomitant influence on MX absorption, retinal tissue responses to MX intake, and the capacity to modify MX-associated factors and processes implicated in AMD pathogenesis.

Diminishing risk for age-related macular degeneration with nutrition: a current view

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly. Clinical hallmarks of AMD are observed in one third of the elderly in industrialized countries. Preventative interventions through dietary modification are attractive strategies, because they are more affordable than clinical therapies, do not require specialists for administration and many studies suggest a benefit of micro- and macro-nutrients with respect to AMD with few, if any, adverse effects. The goal of this review is to provide information from recent literature on the value of various nutrients, particularly omega-3 fatty acids, lower glycemic index diets and, perhaps, some carotenoids, with regard to diminishing risk for onset or progression of AMD. Results from the upcoming Age-Related Eye Disease Study (AREDS) II intervention trial should be particularly informative.

The putative role of lutein and zeaxanthin as protective agents against age-related macular degeneration: promise of molecular genetics for guiding mechanistic and translational research in the field

Age-related macular degeneration (AMD) is the primary cause of vision loss in elderly people of western European ancestry. Genetic, dietary, and environmental factors affect tissue concentrations of macular xanthophylls (MXs) within retinal cell types manifesting AMD pathology. In this article we review the history and state of science on the putative role of the MXs (lutein, zeaxanthin, and meso-zeaxanthin) in AMD and report findings on AMD-associated genes encoding enzymes, transporters, ligands, and receptors affecting or affected by MXs. We then use this context to discuss emerging research opportunities that offer promise for meaningful investigation and inference in the field.

Macular pigment imaging in AREDS2 participants: an ancillary study of AREDS2 subjects enrolled at the Moran Eye Center

PURPOSE

Age-Related Eye Disease Study 2 (AREDS2) is a randomized, placebo-controlled study designed to determine whether supplementation with 10 mg of lutein and 2 mg of zeaxanthin per day can slow the rate of progression of age-related macular degeneration (AMD). Although some biomarkers of response to carotenoid supplementation such as serum concentrations are part of the AREDS2 protocol, measurement of carotenoid concentrations in the eye and other tissues is not. In this approved ancillary study, macular pigment optical density (MPOD), macular pigment distributions, and skin carotenoid levels at enrollment and at each annual visit were measured to assess baseline carotenoid status and to monitor response to assigned interventions.

METHODS

All subjects enrolled at the Moran Eye Center had MPOD and macular pigment spatial distributions measured by dual-wavelength autofluorescence imaging and total skin carotenoids measured by resonance Raman spectroscopy. Results. Baseline MPOD in enrolled subjects was unusually high relative to an age-matched control group that did not consume carotenoid supplements regularly, consistent with the high rate of habitual lutein and zeaxanthin consumption in Utah AREDS2 subjects prior to enrollment. MPOD did not correlate with serum or skin carotenoid measurements.

CONCLUSIONS

Useful information is provided through this ancillary study on the ocular carotenoid status of AREDS2 participants in the target tissue of lutein and zeaxanthin supplementation: The macula. When treatment assignments are unmasked at the conclusion of the study, unique tissue-based insights will be provided on the progression of AMD in response to long-term, high-dose carotenoid supplementation versus diet alone. (ClinicalTrials.gov number, NCT00345176.).

Nutritional modulation of age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly worldwide. It affects 30-50 million individuals and clinical hallmarks of AMD are observed in at least one third of persons over the age of 75 in industrialized countries (Gehrs et al., 2006). Costs associated with AMD are in excess of $340 billion US (American-Health-Assistance-Foundation, 2012). The majority of AMD patients in the United States are not eligible for clinical treatments (Biarnes et al., 2011; Klein et al., 2011). Preventive interventions through dietary modulation are attractive strategies because many studies suggest a benefit of micro- and macronutrients with respect to AMD, as well as other age-related debilities, and with few, if any, adverse effects (Chiu, 2011). Preservation of vision would enhance quality of life for millions of elderly people, and alleviate the personal and public health financial burden of AMD (Frick et al., 2007; Wood et al., 2011). Observational studies indicate that maintaining adequate levels of omega-3 fatty acids (i.e. with 2 servings/week of fish) or a low glycemic index diet may be particularly beneficial for early AMD and that higher levels of carotenoids may be protective, most probably, against neovascular AMD. Intervention trials are needed to better understand the full effect of these nutrients and/or combinations of nutrients on retinal health. Analyses that describe effects of a nutrient on onset and/or progress of AMD are valuable because they indicate the value of a nutrient to arrest AMD at the early stages. This comprehensive summary provides essential information about the value of nutrients with regard to diminishing risk for onset or progress of AMD and can serve as a guide until data from ongoing intervention trials are available.

Effect of 1-year lutein supplementation on macular pigment optical density and visual function

BACKGROUND

Although it is known that antioxidants including lutein can affect macular pigment optical density (MPOD) and visual function, we still have much to learn about their effect. Our aim was to assess the 1-year changes in MPOD and visual function in response to supplementation containing lutein.

METHODS

We prospectively measured the MPOD level of those who received a supplement containing 6 mg of lutein daily for 1 year. MPOD level was measured every 3 months by using autofluorescence spectrometry with the two-wavelength method. Other examinations, including contrast sensitivity and retinal sensitivity were also measured every 3 or 6 months. Stepwise regression analysis was performed to determine the factors that correlated with the changes observed in those examinations.

RESULTS

Forty-three eyes of 43 Japanese subjects, including five normal eyes, five fellow eyes with central serous chorioretinopathy (CSC), and 33 fellow eyes with age-related macular degeneration (AMD) were enrolled. The higher baseline MPOD level was correlated with the eye with a clear intraocular lens (IOL). Although no time-dependent changes in the MPOD level were obtained in any area, subjects without cardiovascular diseases showed higher increase in the MPOD level. We observed significant increases in the contrast sensitivity at 1 year (p = 0.0124) and in the retinal sensitivity at 6 months (p < 0.0001) and 1 year (p < 0.0001). Stepwise regression analysis showed that nonsmokers had increased contrast sensitivity (p = 0.0173), and the fellow eye of those with CSC had less of an increase in retinal sensitivity (p = 0.0491).

CONCLUSIONS

Daily supplementation with 6 mg of lutein did not affect the MPOD level for 1 year, suggesting that 6 mg of lutein may be insufficient to increase the MPOD level. However, supplementation seems to improve visual functions such as contrast sensitivity and retinal sensitivity.

Retinal light toxicity

The ability of light to enact damage on the neurosensory retina and underlying structures has been well understood for hundreds of years. While the eye has adapted several mechanisms to protect itself from such damage, certain exposures to light can still result in temporal or permanent damage. Both clinical observations and laboratory studies have enabled us to understand the various ways by which the eye can protect itself from such damage. Light or electromagnetic radiation can result in damage through photothermal, photomechanical, and photochemical mechanisms. The following review seeks to describe these various processes of injury and many of the variables, which can mitigate these modes of injury.

The value of measurement of macular carotenoid pigment optical densities and distributions in age-related macular degeneration and other retinal disorders

There is increasing recognition that the optical and antioxidant properties of the xanthophyll carotenoids lutein and zeaxanthin play an important role in maintaining the health and function of the human macula. In this review article, we assess the value of non-invasive quantification of macular pigment levels and distributions to identify individuals potentially at risk for visual disability or catastrophic vision loss from age-related macular degeneration, and we consider the strengths and weaknesses of the diverse measurement methods currently available.