Lisa M. Renzi

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BACKGROUND the xanthophylls lutein (L) and zeaxanthin (Z) exist in relatively high concentration in multiple central nervous tissues (e.g. cortex and neural retina). L + Z in macula (i.e. macular pigment, MP) are thought to serve multiple functions, including protection and improvement of visual performance. Also, L + Z in the macula are related to L + Z in(More)
Low carotenoid status (especially of the xanthophylls, lutein [L], and zeaxanthin [Z]) is common in older adults and has been associated with a number of degenerative diseases of the central nervous system ranging from retina (e.g., macular degeneration) to brain (e.g., Alzheimer's disease). In this study, we tested whether retinal measures of L + Z(More)
PURPOSE To compare visual performance in eyes with intraocular lenses (IOLs) that filter short-wave blue light versus contralateral eyes with IOLs that do not filter visible blue light. METHODS In this prospective, assessor-masked study that was conducted at five clinics in the US, eligible candidates were at least 12 months postimplantation of a control(More)
Many applications require knowledge of lens absorption. Measuring lens optical density (OD), however, is often difficult and time-consuming. For example, psychophysical measurement typically requires a long period of dark adaptation (e.g. about 40 min) and assessment of absolute scotopic thresholds. In this study, we examined efficient scotopic and photopic(More)
OBJECTIVES Lutein (L), zeaxanthin (Z), and meso-zeaxanthin are the dominant carotenoids within the central retina (there, termed macular pigment, MP). L is also the dominant carotenoid in the brain. The presence of L and Z in both motor and visual areas of the central nervous system is consistent with a role of these carotenoids in visual-motor behavior.(More)
Critical flicker fusion (CFF), a measure of visual processing speed, has often been regarded as a basic metric underlying a number of higher cognitive functions. To test this, we measured CFF, global cognition, and several cognitive subdomains. Because age is a strong covariate for most of these variables, both younger (n = 72) and older (n = 57) subjects(More)
Macular pigment (MP) selectively filters short-wave light and may improve visual performance via this mechanism. This study was designed to test the hypothesis that MP alters contrast between an object and its background, and thus alters the object's detectability. In order to test this hypothesis, participants of a variety of ages were recruited into two(More)
Lutein and zeaxanthin are major carotenoids in the eye but are also found in post-receptoral visual pathways. It has been hypothesized that these pigments influence the processing of visual signals within and post-retina, and that increasing lutein and zeaxanthin levels within the visual system will lead to increased visual processing speeds. To test this,(More)
Lutein (L) and zeaxanthin (Z) are the dominant carotenoids within the central retina (there, termed macular pigment, MP) and brain (approximately 70% of total carotenoid concentration). Past studies have shown that MP is related to many static indicators of visual performance, such as visibility and disability glare. It has also been shown that MP is(More)
Lutein, a carotenoid found in dark green, leafy vegetables, has been implicated as being protective against the acquired ocular diseases, such as cataracts and age-related macular degeneration. In the eye, lutein may act as an antioxidant and as a blue light filter to protect the underlying tissues from phototoxic damage. Average intakes of lutein in the(More)