Purchase this article with an account.
R.A. Bone, J.T. Landrum, B. Brener; Effects of Lutein Dose, Age and Competency of Subjects on Macular Pigment Measurements . Invest. Ophthalmol. Vis. Sci. 2006;47(13):3806.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate the effects of lutein (L) dose and ageof subjects on the rate of increase in macular pigment opticaldensity (MPOD) measured by heterochromatic flicker photometry(HFP), and the influence on the relationship of subject skillin HFP.
Subjects aged 18 to 30 were divided into 4 age–matchedgroups, each group receiving a 120 day supply of gel caps containing5, 10 or 20 mg of L, or a placebo. Additional subjects aged≥ 50 participated in a 120 day trial taking 20 mg/day of L. MPODwas measured twice per week in each eye by HFP.
For each eye of each subject, we determined the averagerate of increase in MPOD. The rates for the 18 to 30 year oldsubjects were averaged for each dosage group. See Fig 1. Forcomparison, results are included from an earlier study in which2 subjects took 30 mg per day of L. Competency in HFP was judgedby the uncertainty in subjects' rates of increase in MPOD. Asubject whose standard deviation was ≤ 0.25 mAU/day was designatedas competent. For competent subjects in each dosage group, weagain determined the average rate of increase in MPOD. See Fig.2. The average rates of increase in MPOD for the younger andolder 20 mg groups were 0.49 ± 0.63 and 0.13 ±0.66 mAU/day respectively.
The average rate ofincrease in MPOD correlates strongly with L dose, more so ifdata from competent subjects only are included. This resultimplies that more reliable data can be obtained with fewer subjects,provided they are screened for competency in HFP, than witha larger number of subjects who are not screened. Our comparisonof younger and older subjects suggests the potential importanceof age–matching of subjects when comparing effects ofdifferent L doses.
This PDF is available to Subscribers Only