The Impact of Supplemental Antioxidants on Visual Function in Nonadvanced Age-Related Macular Degeneration: A Head-to-Head Randomized Clinical Trial.

Purpose: The purpose of this study was to evaluate the impact of supplemental macular carotenoids (including versus not including meso-zeaxanthin) in combination with coantioxidants on visual function in patients with nonadvanced age-related macular degeneration. Methods: In this study, 121 participants were randomly assigned to group 1 (Age-Related Eye Disease Study 2 formulation with a low dose [25 mg] of zinc and an addition of 10 mg meso-zeaxanthin; n = 60) or group 2 (Age-Related Eye Disease Study 2 formulation with a low dose [25 mg] of zinc; n = 61). Visual function was assessed using best-corrected visual acuity, contrast sensitivity (CS), glare disability, retinal straylight, photostress recovery time, reading performance, and the National Eye Institute Visual Function Questionnaire-25. Macular pigment was measured using customized heterochromatic flicker photometry. Results: There was a statistically significant improvement in the primary outcome measure (letter CS at 6 cycles per degree [6 cpd]) over time (P = 0.013), and this observed improvement was statistically comparable between interventions (P = 0.881). Statistically significant improvements in several secondary outcome visual function measures (letter CS at 1.2 and 2.4 cpd; mesopic and photopic CS at all spatial frequencies; mesopic glare disability at 1.5, 3, and 6 cpd; photopic glare disability at 1.5, 3, 6, and 12 cpd; photostress recovery time; retinal straylight; mean and maximum reading speed) were also observed over time (P < 0.05, for all), and were statistically comparable between interventions (P > 0.05, for all). Statistically significant increases in macular pigment at all eccentricities were observed over time (P < 0.0005, for all), and the degree of augmentation was statistically comparable between interventions (P > 0.05). Conclusions: Antioxidant supplementation in patients with nonadvanced age-related macular degeneration results in significant increases in macular pigment and improvements in CS and other measures of visual function. (Clinical trial, http://www.isrctn.com/ISRCTN13894787).

Relationship between macular pigment and visual function in subjects with early age-related macular degeneration.

PURPOSE: To investigate the relationship between macular pigment (MP) and visual function in subjects with early age-related macular degeneration (AMD). METHODS: 121 subjects with early AMD enrolled as part of the Central Retinal Enrichment Supplementation Trial (CREST; ISRCTN13894787) were assessed using a range of psychophysical measures of visual function, including best corrected visual acuity (BCVA), letter contrast sensitivity (CS), mesopic and photopic CS, mesopic and photopic glare disability (GD), photostress recovery time (PRT), reading performance and subjective visual function, using the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). MP was measured using customised heterochromatic flicker photometry. RESULTS: Letter CS, mesopic and photopic CS, photopic GD and mean reading speed were each significantly (p<0.05) associated with MP across a range of retinal eccentricities, and these statistically significant relationships persisted after controlling for age, sex and cataract grade. BCVA, NEI VFQ-25 score, PRT and mesopic GD were unrelated to MP after controlling for age, sex and cataract grade (p>0.05, for all). CONCLUSIONS: MP relates positively to many measures of visual function in unsupplemented subjects with early AMD. The CREST trial will investigate whether enrichment of MP influences visual function among those afflicted with this condition. TRIAL REGISTRATION NUMBER: ISRCTN13894787.

Enrichment of Macular Pigment Enhances Contrast Sensitivity in Subjects Free of Retinal Disease: Central Retinal Enrichment Supplementation Trials - Report 1.

PURPOSE: The high-performance visual function associated with central vision is mediated by the macula (the central retina), which accumulates three diet-derived pigments (the carotenoids lutein [L], zeaxanthin [Z], and meso-zeaxanthin [MZ]). Our study sought to investigate the impact on visual function, including contrast sensitivity (CS), of supplementation with these naturally occurring carotenoids, in individuals with low retinal concentrations. METHODS: Subjects consumed daily a formulation containing 10 mg L, 2 mg Z, and 10 mg MZ (active group; n = 53) or placebo (n = 52) for a period of 12 months. Study visits were at baseline, 3, 6, and 12 months. Contrast sensitivity at 6 cycles per degree (cpd) was the primary outcome measure (POM). Secondary outcome measures included CS at other spatial frequencies, best-corrected visual acuity (BCVA), glare disability, photostress recovery, and light scatter. Macular pigment optical density (MPOD) was measured using dual-wavelength autofluorescence, and serum carotenoid concentrations were analyzed using high performance liquid chromatography (HPLC). RESULTS: Compared to placebo, statistically significant improvements from baseline CS were detected at 6 (P = 0.002) and 1.2 (P = 0.004) cpd in the active group. Additionally, improvements in CS were commensurate with the observed increases in retinal concentrations of these carotenoids (r = 0.342, P = 0.002 at 6 cpd). CONCLUSIONS: These results indicate that dietary fortification with the macular carotenoids can have meaningful effects on visual function.

The Impact of Cataract, and Its Surgical Removal, on Measures of Macular Pigment Using the Heidelberg Spectralis HRA+OCT MultiColor Device.

PURPOSE: To investigate the effect of cataract (and cataract surgery) on macular pigment (MP) measurements using the Heidelberg Spectralis HRA+OCT MultiColor device. METHODS: Thirty-six patients (age, 54-87 years) scheduled for cataract surgery at the Institute of Eye Surgery, Ireland, were enrolled in this study. Cataracts were graded using the Lens Opacities Classification System (LOCS) III, and surgery was performed using standard phacoemulsification technique with implantation of a Tecnis ZCB00 or Tecnis ZCT intraocular lens. Macular pigment was measured before and after cataract surgery in the operated (study) eye and in the fellow (control) eye. RESULTS: In the study eye, there was statistically significant disagreement in measures of MP taken before and after surgery. At all eccentricities, and also for MP volume, the postsurgery measurements were significantly (P < 0.05) greater, ranging from an average 16% greater at 1.72° to an average 35% greater at 0.23° eccentricity. Eyes exhibiting large disagreement between pre- and postsurgery measurements at a given eccentricity also generally exhibited substantial disagreement at other eccentricities. Overall severity of cataract contributed to greater disagreement between pre- and postoperative measures of MP, as did grade of nuclear opalescence, nuclear color, and posterior subcapsular cataract. In control eyes, there was no statistically significant disagreement in terms of measures of MP taken before and after cataract surgery (P > 0.05 for all; 1-sample t-test). CONCLUSIONS: Macular pigment measurements using the Spectralis are affected by cataract. Accordingly, we recommend that cataract be graded when measuring MP with a device that utilizes dual-wavelength fundus autofluorescence and propose the employment of a correction factor to compensate for cataract when measuring MP.

Concordance of Macular Pigment Measurement Using Customized Heterochromatic Flicker Photometry and Fundus Autofluorescence in Age-Related Macular Degeneration.

PURPOSE: We compared macular pigment (MP) measurements using customized heterochromatic flicker photometry (Macular Metrics Densitometer) and dual-wavelength fundus autofluorescence (Heidelberg Spectralis HRA + OCT MultiColor) in subjects with early age-related macular degeneration (AMD). METHODS: Macular pigment was measured in 117 subjects with early AMD (age, 44-88 years) using the Densitometer and Spectralis, as part of the Central Retinal Enrichment Supplementation Trial (CREST; ISRCTN13894787). Baseline and 6-month study visits data were used for the analyses. Agreement was investigated at four different retinal eccentricities, graphically and using indices of agreement, including Pearson correlation coefficient (precision), accuracy coefficient, and concordance correlation coefficient (ccc). RESULTS: Agreement was poor between the Densitometer and Spectralis at all eccentricities, at baseline (e.g., at 0.25° eccentricity, accuracy = 0.63, precision = 0.35, ccc = 0.22) and at 6 months (e.g., at 0.25° eccentricity, accuracy = 0.52, precision = 0.43, ccc = 0.22). Agreement between the two devices was significantly greater for males at 0.5° and 1.0° of eccentricity. At all eccentricities, agreement was unaffected by cataract grade. CONCLUSIONS: In subjects with early AMD, MP measurements obtained using the Densitometer and Spectralis are not statistically comparable and should not be used interchangeably in either the clinical or research setting. Despite this lack of agreement, statistically significant increases in MP, following 6 months of supplementation with macular carotenoids, were detected with each device, confirming that these devices are capable of measuring change in MP within subjects over time. (http://www.controlled-trials.com number, ISRCTN13894787.).