The relation between the macular carotenoids, lutein and zeaxanthin, and temporal vision

Abstract

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 related to a dynamic measure of visual performance, the critical flicker fusion threshold (CFF). In this study, we examine whether MP is related to CFF in a larger sample. We also test the relation between MP and the more complete temporal contrast sensitivity function (TCSF). A total of 70 participants were assessed for a comparison of MP and the full temporal function. A separate pool of 354 participants was assessed for a MP and CFF comparison. Peak MP density was measured psychophysically (via heterochromatic flicker photometry) using a 1-degree diameter test. CFF was measured using a 1-degree 570 nm test varied at 100% modulation. The full TCSF was measured centrally using a 1-degree, 660 nm test (the modulation depth of which could be adjusted directly by the subject) centered within a 5.5-degree, 660 nm surround. A small fixation point was used to test a 7-degree parafoveal site. MP density was positively related to temporal function as assessed by the full TCSF in the center (n = 70, r = -0.29, p < 0.01) but not at the parafoveal location (p < 0.07). MP was also positively related to critical flicker fusion thresholds (n = 354, r = 0.21, p < 0.0001).

Low macular pigment optical density is associated with lower cognitive performance in a large, population-based sample of older adults

“…CRT is a measure of processing speed, which has been proposed by some researchers to underpin age--related decline in many domains of cognition (Finkel et al, 2005(Finkel et al, , 2009Salthouse, 1996Salthouse, , 2000Verhaeghen and Salthouse, 1997). MP has also been shown to correlate with visual processing ability (Renzi and Hammond, 2010). However, additionally adjusting our results for CRT did not attenuate other observed relationships, suggesting that processing speed does not mediate the relationship between cognitive function and MPOD that we observed.…”

“…However, findings to date regarding the relationship between age and MPOD have been somewhat mixed (Berendschot and van Norren, 2005;Delori et al, 2001;Dietzel et al, 2011;Hammond and Caruso--Avery, 2000;Renzi and Hammond, 2010); therefore, such a relationship cannot be assumed. Furthermore, although there is strong theoretical and empirical support for the protective effect of xanthophyll carotenoids on neural integrity, we sought to explore the possibility that cognition influences the measurement of MPOD by cHFP and whether such confounding (if any) would bias MPOD values toward zero.…”

Why lutein is important for the eye and the brain

“…It is also capable of enhancing contrast by adding luminance contrast information to an edge (Liu et al, 2015;Renzi and Hammond, 2010a). It has been related to visual performance and temporal vision (Renzi and Hammond, 2010b) and it is strongly related to improvements in glare disability and photo stress recovery (Stringham and Hammond, 2007).…”

Overview of Glare Types and Their Relationship With Macular Pigment Optical Density.

“…If MP absorbs short wavelength light from the target and background in equivalent amounts, the ratio will remain comparable regardless of the MP density level. In this instance, high MPOD may diminish visual discomfort but it will not increase target visibility 43,44 . Strictly speaking, MP does not provide direct optical absorption of the glare source but instead filters the masking luminance of the target proportional to the MPOD.…”