The Role of Macular Pigment Density Measures in Future Clinical Studies of Age-Related Macular Degeneration

2017 ◽  
Vol 135 (11) ◽  
pp. 1266
Author(s):  
Anne S. Lindblad
Keyword(s):  
Macular Degeneration ◽  
Clinical Studies ◽  
Macular Pigment ◽  
Age Related Macular Degeneration ◽  
Age Related

Integrity of Foveal Cones in Early Age-related Macular Degeneration

2009 ◽  
Vol 03 (01) ◽  
pp. 68
Author(s):  
Dirk van Norren ◽  
Martijn Kanis ◽  
◽  
Keyword(s):  
Macular Degeneration ◽  
Macular Pigment ◽  
Unique Property ◽  
Age Related Macular Degeneration ◽  
Directional Sensitivity ◽  
Early Age ◽  
Age Related ◽  
The Mean ◽  
Retinal Element

In this article, we highlight a method that probes the directional sensitivity of cones, in particular those in the fovea. Directional sensitivity is a unique property of cones, i.e. it is not shared by any other retinal element, and can be taken as a measure of the health of cones. In a group of healthy subjects, the directional reflection was 1.78%. In early age-related macular degeneration (AMD), despite a healthy-looking fovea, the mean directional reflection was 0.92%; in late AMD, the figure decreased further to 0.86%. These findings point to a malfunctioning of the outer segments. In addition, the method yields an estimate of the optical density of macular pigment. In early AMD, the macular pigment did not differ from normal; this finding did not point to a protecting role of macular pigment in AMD.

scholarly journals Complement C5 is not critical for the formation of sub-RPE deposits in Efemp1 mutant mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Donita L. Garland ◽  
Eric A. Pierce ◽  
Rosario Fernandez-Godino
Keyword(s):  
Macular Degeneration ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Deposit Formation ◽  
Genetic Ablation ◽  
Age Related ◽  
Complement Dysregulation

AbstractThe complement system plays a role in the formation of sub-retinal pigment epithelial (RPE) deposits in early stages of age-related macular degeneration (AMD). But the specific mechanisms that connect complement activation and deposit formation in AMD patients are unknown, which limits the development of efficient therapies to reduce or stop disease progression. We have previously demonstrated that C3 blockage prevents the formation of sub-RPE deposits in a mouse model of EFEMP1-associated macular degeneration. In this study, we have used double mutant Efemp1R345W/R345W:C5-/- mice to investigate the role of C5 in the formation of sub-RPE deposits in vivo and in vitro. The data revealed that the genetic ablation of C5 does not eliminate the formation of sub-RPE deposits. Contrarily, the absence of C5 in RPE cultures promotes complement dysregulation that results in increased activation of C3, which likely contributes to deposit formation even in the absence of EFEMP1-R345W mutant protein. The results also suggest that genetic ablation of C5 alters the extracellular matrix turnover through an effect on matrix metalloproteinases in RPE cell cultures. These results confirm that C3 rather than C5 could be an effective therapeutic target to treat early AMD.

scholarly journals Macular Pigment Optical Density and Photoreceptor Outer Segment Length as Predisease Biomarkers for Age-Related Macular Degeneration

2020 ◽  
Vol 9 (5) ◽  
pp. 1347 ◽  
Author(s):  
Norihiro Nagai ◽  
Sakiko Minami ◽  
Misa Suzuki ◽  
Hajime Shinoda ◽  
Toshihide Kurihara ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Optical Density ◽  
Outer Segment ◽  
Macular Pigment ◽  
Age Related Macular Degeneration ◽  
Segment Length ◽  
Macular Pigment Optical Density ◽  
Photoreceptor Outer Segment ◽  
Age Related ◽  
Fellow Eyes

To explore predisease biomarkers, which may help screen for the risk of age-related macular degeneration (AMD) at very early stages, macular pigment optical density (MPOD) and photoreceptor outer segment (PROS) length were analyzed. Thirty late AMD fellow eyes, which are at high risk and represent the predisease condition of AMD, were evaluated and compared with 30 age-matched control eyes without retinal diseases; there was no early AMD involvement in the AMD fellow eyes. MPOD was measured using MPS2® (M.E. Technica Co. Ltd., Tokyo, Japan), and PROS length was measured based on optical coherence tomography images. MPOD levels and PROS length in the AMD fellow eyes were significantly lower and shorter, respectively, than in control eyes. MPOD and PROS length were positively correlated in control eyes (R = 0.386; p = 0.035) but not in AMD fellow eyes. Twenty (67%) AMD fellow eyes met the criteria of MPOD < 0.65 and/or PROS length < 35 μm, while only five (17%) control eyes did. After adjusting for age and sex, AMD fellow eyes more frequently satisfied the definition (p < 0.001; 95% confidence interval, 3.50–60.4; odds ratio, 14.6). The combination of MPOD and PROS length may be a useful biomarker for screening predisease AMD patients, although further studies are required in this regard.

scholarly journals Age-Related Macular Degeneration: Role of Oxidative Stress and Blood Vessels

2021 ◽  
Vol 22 (3) ◽  
pp. 1296
Author(s):  
Yue Ruan ◽  
Subao Jiang ◽  
Adrian Gericke
Keyword(s):  
Oxidative Stress ◽  
Macular Degeneration ◽  
Vascular Function ◽  
Vascular Dysfunction ◽  
Therapeutic Strategies ◽  
Vision Impairment ◽  
Age Related Macular Degeneration ◽  
Oxygen Species ◽  
Age Related

Age-related macular degeneration (AMD) is a common irreversible ocular disease characterized by vision impairment among older people. Many risk factors are related to AMD and interact with each other in its pathogenesis. Notably, oxidative stress and choroidal vascular dysfunction were suggested to be critically involved in AMD pathogenesis. In this review, we give an overview on the factors contributing to the pathophysiology of this multifactorial disease and discuss the role of reactive oxygen species and vascular function in more detail. Moreover, we give an overview on therapeutic strategies for patients suffering from AMD.

The role of Aflibercept in the management of age-related macular degeneration

2016 ◽  
Vol 16 (5) ◽  
pp. 699-709 ◽  
Author(s):  
Muhammad Hassan ◽  
Rubbia Afridi ◽  
Mohammad Ali Sadiq ◽  
Mohamed Kamel Soliman ◽  
Aniruddha Agarwal ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Age Related Macular Degeneration ◽  
Age Related

scholarly journals A Review of the Role of the Intestinal Microbiota in Age-Related Macular Degeneration

2021 ◽  
Vol 10 (10) ◽  
pp. 2072
Author(s):  
Phoebe Lin ◽  
Scott M. McClintic ◽  
Urooba Nadeem ◽  
Dimitra Skondra
Keyword(s):  
Macular Degeneration ◽  
Intestinal Microbiota ◽  
Retinal Disease ◽  
Age Related Macular Degeneration ◽  
Intestinal Microbiome ◽  
Age Related ◽  
Intestinal Dysbiosis ◽  
Apo E ◽  
Dry Amd

Blindness from age-related macular degeneration (AMD) is an escalating problem, yet AMD pathogenesis is incompletely understood and treatments are limited. The intestinal microbiota is highly influential in ocular and extraocular diseases with inflammatory components, such as AMD. This article reviews data supporting the role of the intestinal microbiota in AMD pathogenesis. Multiple groups have found an intestinal dysbiosis in advanced AMD. There is growing evidence that environmental factors associated with AMD progression potentially work through the intestinal microbiota. A high-fat diet in apo-E-/- mice exacerbated wet and dry AMD features, presumably through changes in the intestinal microbiome, though other independent mechanisms related to lipid metabolism are also likely at play. AREDS supplementation reversed some adverse intestinal microbial changes in AMD patients. Part of the mechanism of intestinal microbial effects on retinal disease progression is via microbiota-induced microglial activation. The microbiota are at the intersection of genetics and AMD. Higher genetic risk was associated with lower intestinal bacterial diversity in AMD. Microbiota-induced metabolite production and gene expression occur in pathways important in AMD pathogenesis. These studies suggest a crucial link between the intestinal microbiota and AMD pathogenesis, thus providing a novel potential therapeutic target. Thus, the need for large longitudinal studies in patients and germ-free or gnotobiotic animal models has never been more pressing.

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