scholarly journals Retinoid analogs and polyphenols as potential therapeutics for age-related macular degeneration

2020 ◽  
Vol 245 (17) ◽  
pp. 1615-1625 ◽  
Author(s):  
Tanu Parmar ◽  
Joseph T Ortega ◽  
Beata Jastrzebska

Progressive retinal degeneration manifesting as age-related macular degeneration (AMD) in the elderly affects millions of individuals worldwide. Among various blinding diseases, AMD is the leading cause of central vision impairment in developed countries. Poor understanding of AMD etiology hampers the development of therapeutics against this devastating ocular disease. Currently, daily intravitreal injections of anti-angiogenic drugs, preventing abnormal vessel growth are the only treatment option for wet AMD. However, for dry AMD associated with retinal atrophy, at present there is no cure available. Recent clinical research has demonstrated beneficial effects of plant-derived compounds for various eye disorders. Thus, the ongoing efforts toward discovering efficient treatments preventing or delaying AMD progression focus on implementing a healthy diet rich in vitamins, including vitamin A, E, and C, minerals and carotenoids, in particular lutein and zeaxanthin, to reduce the disease burden. In addition, studies in cell culture and animal models indicated therapeutic potential of dietary polyphenolic compounds present in fruits and vegetables. These natural compounds protect visual function and retinal morphology likely due to their anti-oxidant and anti-inflammatory properties. Although understanding of the exact mechanism of these compounds’ positive effects requires further investigation, they provide non-invasive alternative to battle AMD-like condition. Additionally, studies carried in animal models mimicking AMD-like pathology, examining the pharmacological potential of particular retinoid analogs, demonstrated promising results for their use, and thus they should be considered as an option in developing therapies for AMD. In here, we summarize the most current knowledge regarding developments of therapeutic options to maintain ocular health and prevent vision loss associated with aging. Impact statement Age-related macular degeneration (AMD) is a devastating retinal degenerative disease. Epidemiological reports showed an expected increasing prevalence of AMD in the near future. The only one existing FDA-approved pharmacological treatment involves an anti-vascular endothelial growth factor (VEGF) therapy with serious disadvantages. This limitation emphasizes an alarming need to develop new therapeutic approaches to prevent and treat AMD. In this review, we summarize scientific data unraveling the therapeutic potential of the specific retinoid and natural compounds. The experimental results reported by us and other research groups demonstrated that retinoid analogs and compounds with natural product scaffolds could serve as lead compounds for the development of new therapeutic agents with potential to prevent or slow down the pathogenesis of AMD.

2019 ◽  
Vol 13 (1) ◽  
pp. 90-99
Author(s):  
Nasim Salimiaghdam ◽  
Mohammad Riazi-Esfahani ◽  
Paula S. Fukuhara ◽  
Kevin Schneider ◽  
M. Cristina Kenney

Age-related Macular Degeneration (AMD) is a type of maculopathy that results in irreversible visual impairment among the aged population in developed countries. The early stages of AMD can be diagnosed by the presence of drusen beneath the retinal pigment epithelial (RPE) cells. The advanced stages of AMD are geographical atrophy (dry type) and neovascular AMD (wet type), which lead to progressive and severe vision loss. The advanced stage of dry AMD can be identified by extensive large drusen, detachment of the RPE layer and finally degeneration of photoreceptors leading to central vision loss. The late stage of wet AMD is diagnosed by the presence of Choroidal Neovascularization (CNV) identified by Optical Coherence Tomography (OCT) or retinal angiography. The principal of AMD management is to impede the progression of early AMD to advanced levels. Patients with CNV are treated with anti-VEGF (Vascular Endothelial Growth Factor) compounds to inhibit blood vessel growth and thereby reducing vision loss. Although preventive methods for dry AMD are under investigation, there are no proven effective treatments. A variety of environmental and genetic related risk factors are associated with increased incidence and progression of AMD. The genetic factors are found in the complement, angiogenic and lipid pathways. However, environmental factors, such as smoking and nutrition, are also major risk factors. Smoking is a modifiable environmental risk factor, which greatly increases the incidence and progress of AMD compared to non-smokers. There is growing evidence for the positive influence of a healthy diet containing high levels of anti-oxidant supplements. The reduction of serum lipids is another effective strategy for prevention AMD. Although no single preventive approach has been identified, knowing the high risk factors of AMD, along with modification of lifestyle is important for this multifactorial disease, especially in populations with higher genetic susceptibility. Though recent progress in early diagnosis of the disease has facilitated early and efficient intervention, further studies are required to gain more clarification of specific pathophysiology. In spite of decades of focused research on AMD, the pathogenesis of AMD is still not completely understood. Recently, numerous novel methods, including imaging techniques, new drug delivery routes, and therapeutic strategies, are improving the management of AMD. In this review, we discuss the current knowledge related to epidemiology and classifications of AMD.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shigeru Honda ◽  
Yasuo Yanagi ◽  
Hideki Koizumi ◽  
Yirong Chen ◽  
Satoru Tanaka ◽  
...  

AbstractThe chronic eye disorder, neovascular age-related macular degeneration (nAMD), is a common cause of permanent vision impairment and blindness among the elderly in developed countries, including Japan. This study aimed to investigate the disease burden of nAMD patients under treatment, using data from the Japan National Health and Wellness surveys 2009–2014. Out of 147,272 respondents, 100 nAMD patients reported currently receiving treatment. Controls without nAMD were selected by 1:4 propensity score matching. Healthcare Resource Utilisation (HRU), Health-Related Quality of Life (HRQoL), and work productivity loss were compared between the groups. Regarding HRU, nAMD patients had significantly increased number of visits to any healthcare provider (HCP) (13.8 vs. 8.2), ophthalmologist (5.6 vs. 0.8), and other HCP (9.5 vs. 7.1) compared to controls after adjusting for confounding factors. Additionally, nAMD patients had reduced HRQoL and work productivity, i.e., reduced physical component summary (PCS) score (46.3 vs. 47.9), increased absenteeism (18.14% vs. 0.24%), presenteeism (23.89% vs. 12.44%), and total work productivity impairment (33.57% vs. 16.24%). The increased number of ophthalmologist visits were associated with decreased PCS score, increased presenteeism and total work productivity impairment. The current study highlighted substantial burden for nAMD patients, requiring further attention for future healthcare planning and treatment development.


Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 84
Author(s):  
Rimjhim Agarwal ◽  
Hung T. Hong ◽  
Alice Hayward ◽  
Stephen Harper ◽  
Neena Mitter ◽  
...  

Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries, such as Australia. Lutein and zeaxanthin are the only two carotenoids found in the macular region of the eye. Studies have shown that an intake of 10 mg and 2 mg per day of lutein and zeaxanthin, respectively, can reduce the rate of progression of AMD. The supply of these carotenoids can only be met through dietary sources or supplements, as these compounds cannot be synthesised by humans. Although lutein is relatively abundant in dietary sources, zeaxanthin has limited sources. In this study, eight orange and three red capsicum varieties were analysed for their carotenoid profiles by UHPLC-DAD-APCI-MS. It was observed that the principal carotenoid for seven of the orange varieties was zeaxanthin, and capsanthin for the three red varieties. One orange variety, which had a darker orange hue, had capsanthin and violaxanthin as its principal carotenoids instead of zeaxanthin. Zeaxanthin concentration (the principal carotenoid) in the seven orange varieties varied from 2.6 ± 0.5 mg/100 g to 25.27 ± 9.4 mg/100 FW, suggesting that as little as 7 g of the high-zeaxanthin line could meet the recommended daily dietary intake of 2 mg/person/day.


Nanoscale ◽  
2017 ◽  
Vol 9 (40) ◽  
pp. 15461-15469 ◽  
Author(s):  
Na-Kyung Ryoo ◽  
Jihwang Lee ◽  
Hyunjoo Lee ◽  
Hye Kyoung Hong ◽  
Hyejin Kim ◽  
...  

Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries and is characterized by the development of choroidal neovascularization (CNV).


2020 ◽  
Vol 77 (5) ◽  
pp. 779-780 ◽  
Author(s):  
Anu Kauppinen

AbstractProlonged life expectancies contribute to the increasing prevalence of age-related macular degeneration (AMD) that is already the leading cause of severe vision loss among the elderly in developed countries. In dry AMD, the disease culminates into vast retinal atrophy, whereas the wet form is characterized by retinal edema and sudden vision loss due to neovascularization originating from the choroid beneath the Bruch’s membrane. There is no treatment for dry AMD and despite intravitreal injections of anti-vascular endothelial growth factor (VEGF) that suppress the neovessel formation, also wet AMD needs new therapies to prevent the disease progression and to serve patients lacking of positive response to current medicines. Knowledge on disease mechanisms is a prerequisite for the drug development, which is hindered by the multifactorial nature of AMD. Numerous distinguished publications have revealed AMD mechanisms at the cellular and molecular level and in this multi-author review, we take a bit broader look at the topic with some novel aspects.


Retina ◽  
2013 ◽  
Vol 33 (8) ◽  
pp. 1487-1502 ◽  
Author(s):  
Raul Velez-Montoya ◽  
Scott C. N. Oliver ◽  
Jeffrey L. Olson ◽  
Stuart L. Fine ◽  
Naresh Mandava ◽  
...  

2014 ◽  
Vol 91 (8) ◽  
pp. 878-886 ◽  
Author(s):  
Erica L. Fletcher ◽  
Andrew I. Jobling ◽  
Ursula Greferath ◽  
Samuel A. Mills ◽  
Michelle Waugh ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Serge Camelo ◽  
Mathilde Latil ◽  
Stanislas Veillet ◽  
Pierre J. Dilda ◽  
René Lafont

Age-related macular degeneration (AMD) is the commonest cause of severe visual loss and blindness in developed countries among individuals aged 60 and older. AMD slowly progresses from early AMD to intermediate AMD (iAMD) and ultimately late-stage AMD. Late AMD encompasses either neovascular AMD (nAMD) or geographic atrophy (GA). nAMD is defined by choroidal neovascularization (CNV) and hemorrhage in the subretinal space at the level of the macula. This induces a rapid visual impairment caused by the death of photoreceptor cells. Intravitreal injection of anti-vascular endothelial growth factor (VEGF) antibodies is the standard treatment of nAMD but adds to the burden of patient care. GA is characterized by slowly expanding photoreceptor, and retinal pigment epithelium (RPE) degeneration patches progressively leading to blindness. There is currently no therapy to cure GA. Late AMD continues to be an unmet medical need representing a major health problem with millions of patients worldwide. Oxidative stress and inflammation are recognized as some of the main risk factors to developing late AMD. The antioxidant formulation AREDS (Age-Related Eye Disease Studies), contains β-carotene, which has been replaced by lutein and zeaxanthin in AREDS2, are given to patients with iAMD but have a limited effect on the incidence of nAMD and GA. Thus, to avoid or slowdown the development of late stages of AMD (nAMD or GA), new therapies targeting iAMD are needed such as crocetin obtained through hydrolysis of crocin, an important component of saffron (Crocus sativus L.), and norbixin derived from bixin extracted from Bixa orellana seeds. We have shown that these apocarotenoids preserved more effectively RPE cells against apoptosis following blue light exposure in the presence of A2E than lutein and zeaxanthin. In this review, we will discuss the potential use of apocarotenoids to slowdown the progression of iAMD, to reduce the incidence of both forms of late AMD.


2020 ◽  
Vol 2020 ◽  
pp. 1-19 ◽  
Author(s):  
Samuel Abokyi ◽  
Chi-Ho To ◽  
Tim T. Lam ◽  
Dennis Y. Tse

Age-related macular degeneration (AMD) is a common cause of visual impairment in the elderly. There are very limited therapeutic options for AMD with the predominant therapies targeting vascular endothelial growth factor (VEGF) in the retina of patients afflicted with wet AMD. Hence, it is important to remind readers, especially those interested in AMD, about current studies that may help to develop novel therapies for other stages of AMD. This study, therefore, provides a comprehensive review of studies on human specimens as well as rodent models of the disease, to identify and analyze the molecular mechanisms behind AMD development and progression. The evaluation of this information highlights the central role that oxidative damage in the retina plays in contributing to major pathways, including inflammation and angiogenesis, found in the AMD phenotype. Following on the debate of oxidative stress as the earliest injury in the AMD pathogenesis, we demonstrated how the targeting of oxidative stress-associated pathways, such as autophagy and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling, might be the futuristic direction to explore in the search of an effective treatment for AMD, as the dysregulation of these mechanisms is crucial to oxidative injury in the retina. In addition, animal models of AMD have been discussed in great detail, with their strengths and pitfalls included, to assist inform in the selection of suitable models for investigating any of the molecular mechanisms.


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