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Dive into the research topics where Maria Makridaki is active.

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Featured researches published by Maria Makridaki.


Investigative Ophthalmology & Visual Science | 2013

Lutein supplementation over a one-year period in early AMD might have a mild beneficial effect on visual acuity: the CLEAR study.

Ian J. Murray; Maria Makridaki; Rob L. P. van der Veen; David Carden; Neil R. A. Parry; Tos T. J. M. Berendschot

PURPOSE We investigated the effect of daily supplementation with lutein (L) capsules on macular pigment optical density (MPOD) and visual acuity (VA) in patients with early age-related macular degeneration (AMD). METHODS A randomized, double-blind, placebo-controlled, two-center investigation of the effects of L supplementation in early AMD was conducted. The duration of the trial was 12 months. The centers were Manchester, United Kingdom and Maastricht, the Netherlands. L capsules (10 mg Ester) or a placebo (P) were taken daily. There were 72 patients (mean age 70.5 ± 8.7) assigned randomly to either L (n = 36) or P (n = 36) groups. MPOD using a flicker-based technique (MPS9000) and best corrected VA (LogMAR) were measured at the beginning and at 4-month intervals over the duration of the 12-month supplementation period. Blood serum samples were collected to monitor compliance. RESULTS At the end of the trial, an overall increase in the mean MPOD level was found for the L group from 0.38 ± 0.19 to 0.53 ± 0.22 optical density (OD) units. According to a mixed design ANOVA, this was statistically significant (P < 0.001). No change in MPOD was found for the P group. There was no significant change in VA in the L group (n = 36). The P group (n = 36) showed a statistically significant deterioration from 0.05 ± 0.13 to 0.09 ± 0.13 (P < 0.05). When comparing the change in VA over the supplementation period, there was a significant difference between the two groups (P < 0.05). To avoid ceiling effects, 2 subgroups of patients with VA worse than 0.06 at baseline were reanalyzed. In the L subgroup (n = 19) a mean improvement in VA from 0.23 ± 0.12 at baseline to 0.16 ± 0.10 at visit 4 was observed (P < 0.05). In the P subgroup (n = 14), there was a small deterioration from 0.18 ± 0.13 to 0.19 ± 0.12 (P = 0.70). The improvement in VA in the L subgroup was compared to the deterioration in VA in the P group and this effect reached statistical significance (P < 0.05). CONCLUSIONS L supplementation increases MPOD levels in early stage AMD patients. According to the VA measurements, the progress of the disease might be slowed in some patients with augmented levels of MP. (ClinicalTrials.gov number NCT01042860.).


Journal of Biomedical Optics | 2009

Correspondence between retinal reflectometry and a flicker-based technique in the measurement of macular pigment spatial profiles

Rob L. P. van der Veen; Tos T. J. M. Berendschot; Maria Makridaki; Fred Hendrikse; David Carden; Ian J. Murray

A comparison of macular pigment optical density (MPOD) spatial profiles determined by an optical and a psychophysical technique is presented. We measured the right eyes of 19 healthy individuals, using fundus reflectometry at 0, 1, 2, 4, 6, and 8 deg eccentricity; and heterochromatic flicker photometry (HFP) at 0, 0.5, 1, 2, 3, 4, 5, 6, and 7 deg, and a reference point at 8 deg eccentricity. We found a strong correlation between the two techniques. However, the absolute estimates obtained by fundus reflectometry data were higher than by HFP. These differences could partly be explained by the fact that at 8 deg eccentricity the MPOD is not zero, as assumed in HFP. Furthermore, when performing HFP for eccentricities of <1 deg, we had to assume that subjects set flicker thresholds at 0.4 deg horizontal translation when using a 1-deg stimulus. MPOD profiles are very similar for both techniques if, on average, 0.05 DU is added to the HFP data at all eccentricities. An additional correction factor, dependent on the steepness of the MPOD spatial distribution, is required for 0 deg.


PLOS ONE | 2013

The effect of lutein supplementation on blood plasma levels of complement factor D, C5a and C3d.

Yuan Tian; Aize Kijlstra; Rob L. P. van der Veen; Maria Makridaki; Ian J. Murray; Tos T. J. M. Berendschot

Lutein is selectively taken up by the primate retina and plays an important role as a filter for harmful blue light and as an antioxidant. Recent studies have shown that lutein has systemic anti-inflammatory properties. Dietary lutein has been associated with reduced circulating levels of inflammatory biomarkers such as CRP and sICAM. Whether lutein also affects activation of the complement system has not yet been addressed and was the purpose of the study described here. Seventy-two subjects with signs of early macular degeneration were randomly assigned to receive either a 10 mg lutein supplement or a placebo during one year. EDTA blood samples were collected at 0, 4, 8 and 12 months. Complement factor D (CFD), a rate limiting component of the alternative pathway of complement activation and the complement activation products C5a and C3d were determined in the plasma samples by ELISA. A significant 0.11 µg/ml monthly decrease in plasma CFD concentration was observed in the lutein group (p<0.001), resulting in a 51% decrease from 2.3 µg/ml at baseline to 1.0 µg/ml at 12 months. The C5a concentration showed a significant 0.063ng/ml monthly decrease in the lutein group (p<0.001) resulting in a 36% decrease from 2.2ng/ml at baseline to 1.6ng/ml at 12 months. The C3d concentration showed a significant 0.19µg/ml monthly decrease in the lutein group (p=0.004) that gave rise to a 9% decrease from 15.4µg/ml at baseline to 14.4µg/ml at 12 months. In the placebo group we found a significant 0.04 µg/ml monthly decrease in plasma CFD concentration, whereas no changes were observed for C5a and C3d. Lutein supplementation markedly decreases circulating levels of the complement factors CFD, C5a and C3d levels, which might allow a simple method to control this inflammatory pathway of the innate immune system.


Ophthalmic and Physiological Optics | 2009

Macular pigment measurement in clinics: controlling the effect of the ageing media

Maria Makridaki; David Carden; Ian J. Murray

We report a series of experiments designed to ensure that Macular Pigment Optical Density (MPOD) measurements obtained with a clinical instrument are not influenced by lens yellowing and ocular media optical density. These effects were determined in six subjects using seven Lee Colour Temperature Correcting filters to simulate changes in the transmittance of the ocular media with age. Calculated simulated age matched the data linking age and optical density reported in the literature, and the MPOD was independent of simulated age. The instrument allows an estimation of MPOD to be made which is based only on a foveal (centre‐only) measurement rather than, as is conventional, making a comparison between foveal and peripheral measurements. We assessed the performance of this facility by comparing the centre‐only estimate of MPOD with that obtained from both central and peripheral measurements in 5616 eyes. The 95% limits of agreement for the two estimates was 0.13 OD units.


Acta Ophthalmologica | 2011

Assessment of macular pigment optical density (MPOD) in patients with unilateral wet age-related macular degeneration (AMD)

Chrysanthi Tsika; Miltiadis K. Tsilimbaris; Maria Makridaki; Georgios A. Kontadakis; Sotiris Plainis; Joanna Moschandreas

Purpose:  To compare the macular pigment optical density (MPOD) of patients with unilateral wet age‐related macular degeneration (AMD) with the MPOD of bilateral dry AMD patients and healthy elderly individuals.


Acta Ophthalmologica | 2015

Lutein supplementation leads to decreased soluble complement membrane attack complex sC5b-9 plasma levels

Yuan Tian; Aize Kijlstra; R.L.P. van der Veen; Maria Makridaki; Ian J. Murray; Tos T. J. M. Berendschot

The purpose of this study was to investigate the effect of lutein on systemic complement activation in elderly individuals.


Acta Ophthalmologica | 2012

Assessment of macular pigment optical density in patients with unilateral wet age‐related macular degeneration: authors reply

Chrysanthi Tsika; Miltiadis K. Tsilimbaris; Maria Makridaki; Georgios A. Kontadakis; Sotiris Plainis; Joanna Moschandreas

Department of Ophthalmology, Faculty of Medicine, University Hospital of Heraklion, Crete, Heraklion, Greece Institute of Vision & Optics, Faculty of Medicine, School of Health Sciences, University of Crete, Crete, Greece Department of Optometry and Neuroscience, Faculty of Life Sciences, University of Manchester, Manchester, UK Preventive Medicine and Nutrition Clinic, Division of Social Medicine, Faculty of Medicine, School of Health Sciences, University of Crete, Crete, Greece


Investigative Ophthalmology & Visual Science | 2011

The Clear (combination (of) Lutein Effects (on) Aging Retina) Study; Lutein Supplementation Improves Visual Acuity And Night Vision In Early Amd; A Two-centre, Placebo-controlled Study

Tos T. J. M. Berendschot; Maria Makridaki; Rob L. P. van der Veen; Neil Ra Parry; Dave Carden; Ian J. Murray


Investigative Ophthalmology & Visual Science | 2009

Assessment of Macular Pigment Optical Density in Patients With Unilateral Wet Amd

Chrysanthi Tsika; Georgios A. Kontadakis; Maria Makridaki; Sotiris Plainis; Joanna Moschandreas; Ioannis G. Pallikaris; M Tsilimbaris


Investigative Ophthalmology & Visual Science | 2013

Lutein supplementation leads to a decreased level of circulating complement factors

Tos T. J. M. Berendschot; Yuan Tian; Ian J. Murray; Maria Makridaki; Rob L. P. van der Veen; Aize Kijlstra

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David Carden

University of Manchester

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Ian J. Murray

University of Manchester

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I. J. Murray

University of Manchester

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