Pigment Density

Density is determined by pyknometry at a standard temperature of 25°C. For standards, see Table 1.1 ( Density ). Apparatus pyknometer, vacuum pump or centrifuge. 

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JOHNSON E J, HAMMOND B R, YEUM K, J, QIN J, WANG X D, CASTANEDA C, SNODDERLY D M and RUSSELL R M (2000) Relation among serum and tissue concentrations of lutein and zeaxanthin and macular pigment density. Am J Clin Nutr. 71(6) 1555-62. 

Bour, L. J. et al. (2002). Fundus photography for measurement of macular pigment density distribution in children. Investigative Ophthalmology and Visual Science 43 1450-1455. 

Delori, F. C. et al. (2001). Macular pigment density measured by autofluorescence spectrometry Comparison with reflectometry and heterochromatic flicker photometry. Journal of the Optical Society of America A 18 1212-1230. 

Hammond Jr., B. R. and K. Fuld (1992). Interocular differences in macular pigment density. Investigative Ophthalmology Visual Science 33 350-355. 

Robson, A. G. et al. (2003). Macular pigment density and distribution Comparison of fundus autofluorescence with minimum motion photometry. Vision Research 43(16) 1765-1775. 

Rodriguez-Carmona, M. et al. (2006). The effects of supplementation with lutein and/or zeaxanthin on human macular pigment density and colour vision. Ophthalmic and Physiological Optics 26 137-147. 

Van de Kraats, J. et al. (2006). Fast assessment of the central macular pigment density with natural pupil using the macular pigment reflectometer. Journal of Biomedical Optics 11 064031. 

Werner, J. S. et al. (1987). Aging and the human macular pigment density. Appended with translations from the work of Max Schultz and Ewald Hering. Vision Research 27 257-68. 

Wtistemeyer, H. et al. (2002). A new instrument for the quantification of macular pigment density First results in patients with AMD and healthy subjects. Graefe s Archive for Clinical and Experimental Ophthalmology. 240 666-671. 

Bone, R. A., J. T. Landrum et al. (2003). Lutein and zeaxanthin dietary supplements raise macular pigment density and serum concentrations of these carotenoids in humans. J. Nutr. 133(4) 992-998. 

Wolf-Schnurrbusch, U. E. K., N. Roosli et al. (2007). Ethnic differences in macular pigment density and distribution. Invest. Ophthalmol. Vis. Sci. 48(8) 3783-3787. 

Yolton, D., B. DeRuyter et al. (2002). Failure of oral supplement containing lutein to change macular pigment density. Optom. Vis. Sci. 79(12) 104. 

As the therapy of AMD is very limited, there is an urgent need to develop an intervention to prevent vision loss. The epidemiological data together with the well-documented antioxidant properties of carotenoids in studies in vitro and with proven increases in macular pigment density in most people via dietary supplementation (Beatty et al., 2004 Berendschot et al., 2000 Bone et al., 2003 Hammond et al., 1997 Iannaccone et al., 2007 Landrum et al., 1997), including patients with early AMD (Koh et al., 2004 Obana et al., 2008 Richer et al., 2007 Trieschmann... 

Furthermore, several studies have shown that in some individuals an increased intake of xanthophylls does not lead to increased levels of xanthophylls in their plasmas and/or retinas, and macular pigment densities do not exhibit a positive correlation with plasma levels of lutein and zeaxanthin (Aleman et al., 2001 Bernstein et al., 2002b Bone et al., 2000, 2001, 2003 Hammond et al., 1995,1997). These apparently conflicting epidemiological results need to be interpreted with caution as a diet rich in fruit and vegetables includes a great variety of phytochemicals that may independently, or in cooperation with lutein or zeaxanthin, and other dietary components affect carotenoid uptake and function in the retina. 

Hammond, BR, Fuld, K, and Currancelentano, J, 1995. Macular pigment density in monozygotic twins. Invest Ophthalmol Vis Sci 36, 2531-2541. 

Hammond, BR, Johnson, EJ, Russell, RM, Krinsky, NI, Yeum, KJ, Edwards, RB, and Snodderly, DM, 1997. Dietary modification of human macular pigment density. Invest Ophthalmol Vis Sci 38, 1795-1801. 

LaRowe, TL, Mares, JA, Snodderly, DM, Klein, ML, Wooten, BR, and Chappell, R, 2008. Macular pigment density and age-related maculopathy in the Carotenoids in Age-Related Eye Disease Study. An ancillary study of the women s health initiative. Ophthalmology 115, 876-883 e871. 

Werner, JS, Donnelly, SK, and Kliegl, R, 1987. Aging and human macular pigment density. Vision Res 27, 257-268. 

Fig. 12.16. Resonance Raman images of macular pigment distributions obtained for the same subject with the Raman method (a) and with a fluorescence-based imaging method (b) (c) comparison of integrated pigment densities obtained for 16 volunteer subjects with both imaging methods. A high correlation coefficient of R=0.89 is obtained for the correlation between both methods...

Ciulla, T. A., and Hammond, B.R. Macular pigment density and aging, assessed in the normal elderly and those with cataracts and age-related macular degeneration, Am. J. Ophthalmol., 138(4), 582-587, 2004. 

Pigments Density (g cm-3) Refractive index a(BET) (m2 g"1) Crystal size (pm)... 

Zinc Sulfide (1851) n. Pigment white 7 (77975). ZnS. Yellowish white pigment, soluble in acids, and insoluble in water. Certain specially treated grades of this pigment are used as fluorescent pigments. Density, 4.0g/cm (33.3lb/gal) O.A., 13 particle size, 0.25 pm refractive index, 2.37. 

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