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Macular Pigment Optical Density (macular + pigment_optical_density)

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Medical Sciences100%

Selected Abstracts

Macular pigment optical density at four retinal loci during 120 days of lutein supplementation

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 4 2007
Adam J. Wenzel
Abstract Background:, Increased consumption of lutein and zeaxanthin has been shown to increase macular pigment optical density (MPOD) in some individuals. Most interventions either obtained infrequent measures of MPOD or measured MPOD at a single retinal locus. Purpose:, The aim of this study was to measure acute changes in MPOD at four retinal loci during lutein intervention. Methods:, For 120 days, three subjects consumed 30 mg of lutein and 2.7 mg of zeaxanthin supplement per day. MPOD was measured with heterochromatic flicker photometry at 20,, 30,, 60, and 120, eccentricity three or four times per week. High-performance liquid chromatography was used to measure serum carotenoid concentrations in blood samples collected at baseline and at 30-day intervals. Results:, At the two most central loci, MPOD significantly increased in all three subjects with a mean change of approximately 0.09 log units at 20, eccentricity and 0.08 log units at 30, eccentricity. MPOD significantly increased in two subjects at 60, eccentricity, and in one subject at 120, eccentricity. The increases in MPOD appeared to be linear and continued after treatment was ended. In all three subjects, log sensitivity at the reference locus decreased linearly. Serum lutein and serum zeaxanthin increased from baseline, reaching peak concentrations after 30 days of supplementation. Conclusion:, The changes in MPOD suggest that carotenoid deposition occurs linearly and may be biased towards the central retina. Further, carotenoid deposition may occur outside the central fovea in interventions with pharmacological doses of carotenoid, resulting in underestimations of psychophysical measures of MPOD. [source]

A new desktop instrument for measuring macular pigment optical density based on a novel technique for setting flicker thresholds

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 2 2009
Rob L. P. Van Der Veen
Abstract A rapid portable technique for estimating macular pigment optical density (MPOD) in large populations is described. The new instrument utilises a novel method for setting flicker thresholds which is undemanding for naïve and elderly observers and easily operated by a non-technical person. The method has good repeatability (r = 0.97) and the data are comparable with an optical method based on retinal reflectometry (r = 0.78). MPOD spatial profiles are presented for seven normal observers and these are well described (r = 0.99) by a decaying exponential function consistent with previous reports. MPOD values are presented from 5581 (2435 females and 3146 males) individuals measured in 48 optometric practices. The mean MPOD of this population was 0.33 (S.D. ± 0.187) which is similar to previous large scale studies of MP. [source]

Macular pigment optical density at four retinal loci during 120 days of lutein supplementation

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 4 2007
Adam J. Wenzel
Abstract Background:, Increased consumption of lutein and zeaxanthin has been shown to increase macular pigment optical density (MPOD) in some individuals. Most interventions either obtained infrequent measures of MPOD or measured MPOD at a single retinal locus. Purpose:, The aim of this study was to measure acute changes in MPOD at four retinal loci during lutein intervention. Methods:, For 120 days, three subjects consumed 30 mg of lutein and 2.7 mg of zeaxanthin supplement per day. MPOD was measured with heterochromatic flicker photometry at 20,, 30,, 60, and 120, eccentricity three or four times per week. High-performance liquid chromatography was used to measure serum carotenoid concentrations in blood samples collected at baseline and at 30-day intervals. Results:, At the two most central loci, MPOD significantly increased in all three subjects with a mean change of approximately 0.09 log units at 20, eccentricity and 0.08 log units at 30, eccentricity. MPOD significantly increased in two subjects at 60, eccentricity, and in one subject at 120, eccentricity. The increases in MPOD appeared to be linear and continued after treatment was ended. In all three subjects, log sensitivity at the reference locus decreased linearly. Serum lutein and serum zeaxanthin increased from baseline, reaching peak concentrations after 30 days of supplementation. Conclusion:, The changes in MPOD suggest that carotenoid deposition occurs linearly and may be biased towards the central retina. Further, carotenoid deposition may occur outside the central fovea in interventions with pharmacological doses of carotenoid, resulting in underestimations of psychophysical measures of MPOD. [source]

Supplementation with the carotenoids lutein or zeaxanthin improves human visual performance

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 4 2006
Jessica Kvansakul
Abstract Background:, Macular pigment (MP) is found in diurnal primate species when vision spans a range of ambient illumination and is mediated by cone and rod photoreceptors. The exact role of MP remains to be determined. In this study we investigate two new hypotheses for possible MP functions. Objective:, As MP absorption coincides partly with that of rhodopsin, MP may reduce rod signal effectiveness in the mesopic range, thus extend the usefulness of cone-mediated vision into the mesopic range. Forward light scatter in the eye can reduce retinal image contrast. If blue light contributes significantly to intraocular scatter, selective blue light absorption by MP could reduce the effects of scatter. Design:, We investigated 34 subjects from a carotenoid supplementation trial. The measurements included high mesopic contrast acuity thresholds (CATs), macular pigment optical density (MPOD), wavefront aberrations, and scattered light. The measurements were made after 6 months of daily supplementation with zeaxanthin (Z, OPTISHARPÔ), lutein (L), a combination of the two (C), or placebo (P), and again after a further 6 months of doubled supplementation. Results:, The data reveal a trend toward lower CATs in all groups supplemented, with a statistically significant improvement in the lutein group (p = 0.001), although there was no correlation with MPOD. Light scattering in the eye and the root-mean-square wavefront aberrations show decreasing trends as a result of supplementation, but no correlation with MPOD. Conclusions:, The results suggest that supplementation with L or Z increases MPOD at the fovea and at 2.5°, and that supplementation can improve CATs at high mesopic levels and hence visual performance at low illumination. [source]

Repeated measures of macular pigment optical density to test reproducibility of heterochromatic flicker photometry

ACTA OPHTHALMOLOGICA, Issue 2 2010
Stefan Hagen
Abstract. Purpose:, To report the reproducibility of macular pigment optical density (MPOD) values assessed with heterochromatic flicker photometry (HFP) in healthy individuals. Methods:, Twenty-four volunteers from our department underwent MPOD testing of both eyes by flicker photometry on three separate occasions. To test reproducibility of MPOD, the coefficient of variance was calculated separately for right and left eyes. In addition, we investigated MPOD averages of right and left eyes and interocular correlations (Pearson's r) at every visit. Results:, The mean MPODs at the first visit were 0.61 ± 0.24 and 0.72 ± 0.27 in right and left eyes, respectively. Mean values of 0.58 ± 0.29 and 0.60 ± 0.21 (second visit) and 0.62 ± 0.27 and 0.63 ± 0.24 (third visit) were assessed for right and left eyes, respectively. Differences of the mean values between eyes were not significant. Correlations were weak at visits one and two (r = 0.49, p < 0.014 and r = 0.43, p < 0.038, respectively) and moderate at visit three (r = 0.58, p < 0.003). The coefficients of variance were 36.1% and 23% for right and left eyes, respectively. Conclusion:, Our mean MPODs are higher and the interocular correlations weaker compared to the literature. The coefficient of variance in both eyes is high and does not imply good reproducibility of obtained MPOD values. [source]