Macular pigment determinants

Bone, R. A. et al. (2007a). Macular pigment, photopigments and melanin Distributions in young subjects determined by four-wavelength reflectometry. Vision Research 47 3259-3268. 

Berendschot TTJM and van Norren D (2004), Objective determination of the macular pigment optical density using fundus reflectance spectroscopy, Arch. Biochem. Biophys. 430 149-155. 

Based on anatomical studies, we can conclude that it is very unlikely that subjects exist with no L and Z within their retinas. Although it is somewhat common to report zero MP levels in the literature, the determination of zero is made based on calculations derived from relative stimulus conditions used within the study. All retinal L and Z are derived from the diet3 and L, for instance, is a relatively ubiquitous nutrient. No macular pigment within the retina would imply no L and Z within the diet for a relatively long period (analogous to the controlled diet study of Malinow et al.93). This occurrence is certainly possible but would be very rare in developed countries. Individuals with very low intake (e.g., from impoverished countries), however, might be expected to have only trace amounts of L and Z within their retinas. An alternative hypothesis is discussed later (see Genetics and Heritability ). 

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