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Purpose: Accurate assessment of the amount of macular pigment (MPOD) is necessary to investigate the role of carotenoids and their assumed protective functions. High repeatability and reliability are important to monitor patients in studies investigating the influence of diet and supplements on MPOD. We evaluated the Macuscope (Macuvision Europe Ltd., Lapworth, Solihull, UK), a recently introduced device for measuring MPOD using the technique of heterochromatic flicker photometry (HFP). We determined agreement with another HFP device (QuantifEye; MPS 9000 series: Tinsley Precision Instruments Ltd., Croydon, Essex, UK) and a fundus reflectance method., Methods: The right eyes of 23 healthy subjects (mean age 33.9 ± 15.1 years) were measured. We determined agreement with QuantifEye and correlation with a fundus reflectance method. Repeatability of QuantifEye was assessed in 20 other healthy subjects (mean age 32.1 ± 7.3 years). Repeatability was also compared with measurements by a fundus reflectance method in 10 subjects., Results: We found low agreement between test and retest measurements with Macuscope. The average difference and the limits of agreement were -0.041 ± 0.32. We found high agreement between test and retest measurements of QuantifEye (-0.02 ± 0.18) and the fundus reflectance method (-0.04 ± 0.18). MPOD data obtained by Macuscope and QuantifEye showed poor agreement: -0.017 ± 0.44. For Macuscope and the fundus reflectance method, the correlation coefficient was r = 0.05 (P = 0.83). A significant correlation of r = 0.87 (P<0.001) was found between QuantifEye and the fundus reflectance method., Conclusions: Because repeatability of Macuscope measurements was low (ie, wide limits of agreement) and MPOD values correlated poorly with the fundus reflectance method, and agreed poorly with QuantifEye, the tested Macuscope protocol seems less suitable for studying MPOD.

Purpose: Macular pigment is composed of 2 dietary carotenoids, lutein and zeaxanthin, and is mainly present at the nerve fiber layers and ganglion cell layers of the retina, with peak concentrations in the fovea. It is thought to function as a blue-light filter and antioxidant, and therefore protect the retina from damaging influences that are thought to play a role in the pathogenesis of age-related macular degeneration. This study was performed to investigate the suggested positive relationship between foveal macular pigment optical density (MPOD) and foveal retinal thickness., Methods: We determined MPOD and foveal thickness in the right eyes of 40 healthy Caucasian subjects (5 men, 35 women) recruited at the University of Maastricht, The Netherlands. Their mean age was 24.4+/-8.7 years. MPOD was determined by using a novel method of heterochromatic flicker photometry (HFP), where subjects have to detect flicker instead of conventionally minimizing a present flicker motion. Foveal thickness parameters were obtained using optical coherence tomography (OCT 3)., Results: We found a positively significant correlation between MPOD and central foveal thickness (r=0.359, p=0.027). In addition, we found a negatively significant correlation between foveal thickness and foveal width (r= -0.558, p<0.001)., Conclusions: Our data confirm the previously suggested positively significant correlation between MPOD and central foveal thickness. The observed negative relationship between foveal thickness and foveal width may be explained by eccentric scans on the OCT.

Recently, a unique distribution, namely a reduction of macular pigment optical density (MPOD) within the central retina with a surrounding ring-like structure of preserved MPOD at about 6 degrees eccentricity was suggested to be a common finding in macular telangiectasia (MacTel) type 2. In order to quantify this reduced MPOD, 28 eyes of 14 patients with MacTel type 2 were investigated by fundus reflectometry and two wavelengths fundus autofluorescence (FAF; at 488 nm and 514 nm). Fundus reflectometry showed a reduced MPOD within the central 4 degrees eccentricity that was most absent temporal to the foveola. At 6 degrees, MP density was not different from normative values. Two wavelengths FAF was in accordance with these findings. Fundus reflectometry also allowed separate determination of lutein and zeaxanthin. The patients with MacTel type 2 showed a disproportionally high zeaxanthin reduction. The study suggests that in MacTel type 2, there might be an inability to accumulate MP in the central retina. This disease might serve as a model to further study abnormalities of MP distribution in retinal disorders and to elucidate the mechanisms of MP deposition in the retina.

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.

Purpose: To determine the distribution of macular pigment in type 2 idiopathic macular telangiectasia (IMT)., Methods: Twenty-two eyes of 12 patients with type 2 IMT were examined by means of best-corrected visual acuity testing, fundus biomicroscopy, fundus photography, fluorescein angiography, and optical coherence tomography. Macular pigment optical density (MPOD) was assessed using a modified confocal scanning laser ophthalmoscope whereby MPOD was calculated from fundus autofluorescence images acquired at two different excitation wavelengths (488 and 514 nm). The results were verified with a method that provides density maps after digital subtraction of log fundus reflectance maps (four patients) and by means of heterochromatic flicker photometry (four patients)., Results: MOPD distribution showed an abnormal pattern for all patients with type 2 IMT. In correspondence to the late-phase hyperfluorescent areas shown by fluorescein angiography, MPOD was reduced in the macular area, while there was preserved MPOD at 5 degrees to 7 degrees eccentricity., Conclusions: The central depletion of macular pigment represents a novel phenotypic characteristic of type 2 IMT. Recording of macular pigment distribution may prove useful in the diagnosis of type 2 IMT and implicates an impaired trafficking or storage of lutein and zeaxanthin in the disease process.