scholarly journals CRISPR Technology for Ocular Angiogenesis

2020 ◽  
Vol 2 ◽  
Author(s):  
Sook Hyun Chung ◽  
Tzu-Ni Sin ◽  
Taylor Ngo ◽  
Glenn Yiu
Keyword(s):  
Genome Editing ◽  
Viral Vector ◽  
Developed Countries ◽  
Regulatory Elements ◽  
Age Related Macular Degeneration ◽  
Vegf Receptor ◽  
Retinal Diseases ◽  
Ocular Angiogenesis ◽  
Advantages And Disadvantages ◽  
Age Related

Among genome engineering tools, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based approaches have been widely adopted for translational studies due to their robustness, precision, and ease of use. When delivered to diseased tissues with a viral vector such as adeno-associated virus, direct genome editing can be efficiently achieved in vivo to treat different ophthalmic conditions. While CRISPR has been actively explored as a strategy for treating inherited retinal diseases, with the first human trial recently initiated, its applications for complex, multifactorial conditions such as ocular angiogenesis has been relatively limited. Currently, neovascular retinal diseases such as retinopathy of prematurity, proliferative diabetic retinopathy, and neovascular age-related macular degeneration, which together constitute the majority of blindness in developed countries, are managed with frequent and costly injections of anti-vascular endothelial growth factor (anti-VEGF) agents that are short-lived and burdensome for patients. By contrast, CRISPR technology has the potential to suppress angiogenesis permanently, with the added benefit of targeting intracellular signals or regulatory elements, cell-specific delivery, and multiplexing to disrupt different pro-angiogenic factors simultaneously. However, the prospect of permanently suppressing physiologic pathways, the unpredictability of gene editing efficacy, and concerns for off-target effects have limited enthusiasm for these approaches. Here, we review the evolution of gene therapy and advances in adapting CRISPR platforms to suppress retinal angiogenesis. We discuss different Cas9 orthologs, delivery strategies, and different genomic targets including VEGF, VEGF receptor, and HIF-1α, as well as the advantages and disadvantages of genome editing vs. conventional gene therapies for multifactorial disease processes as compared to inherited monogenic retinal disorders. Lastly, we describe barriers that must be overcome to enable effective adoption of CRISPR-based strategies for the management of ocular angiogenesis.

Gene editing prospects for treating inherited retinal diseases

2019 ◽  
Vol 57 (7) ◽  
pp. 437-444 ◽  
Author(s):  
Daniela Benati ◽  
Clarissa Patrizi ◽  
Alessandra Recchia
Keyword(s):  
Genome Editing ◽  
Genetic Disorder ◽  
Retinal Pigment ◽  
Treatment Options ◽  
Genetic Defect ◽  
Retinal Dystrophy ◽  
Retinal Pigment Epithelial Cells ◽  
Age Related Macular Degeneration ◽  
Retinal Diseases ◽  
Age Related

Retinal diseases (RD) include inherited retinal dystrophy (IRD), for example, retinitis pigmentosa and Leber’s congenital amaurosis, or multifactorial forms, for example, age-related macular degeneration (AMD). IRDs are clinically and genetically heterogeneous in nature. To date, more than 200 genes are known to cause IRDs, which perturb the development, function and survival of rod and cone photoreceptors or retinal pigment epithelial cells. Conversely, AMD, the most common cause of blindness in the developed world, is an acquired disease of the macula characterised by progressive visual impairment. To date, available therapeutic approaches for RD include nutritional supplements, neurotrophic factors, antiangiogenic drugs for wet AMD and gene augmentation/interference strategy for IRDs. However, these therapies do not aim at correcting the genetic defect and result in inefficient and expensive treatments. The genome editing technology based on clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein (Cas) and an RNA that guides the Cas protein to a predetermined region of the genome, represents an attractive strategy to tackle IRDs without available cure. Indeed, CRISPR/Cas system can permanently and precisely replace or remove genetic mutations causative of a disease, representing a molecular tool to cure a genetic disorder. In this review, we will introduce the mechanism of CRISPR/Cas system, presenting an updated panel of Cas variants and delivery systems, then we will focus on applications of CRISPR/Cas genome editing in the retina, and, as emerging treatment options, in patient-derived induced pluripotent stem cells followed by transplantation of retinal progenitor cells into the eye.

scholarly journals Organ Cultures for Retinal Diseases

2020 ◽  
Vol 14 ◽  
Author(s):  
José Hurst ◽  
Agnes Fietz ◽  
Teresa Tsai ◽  
Stephanie C. Joachim ◽  
Sven Schnichels
Keyword(s):  
Cellular Responses ◽  
Age Related Macular Degeneration ◽  
Model Systems ◽  
Retinal Diseases ◽  
Animal Testing ◽  
Organ Cultures ◽  
Histological Techniques ◽  
Advantages And Disadvantages ◽  
Age Related

The successful development of novel therapies is closely linked with understanding the underlying pathomechanisms of a disease. To do so, model systems that reflect human diseases and allow for the evaluation of new therapeutic approaches are needed. Yet, preclinical animal studies often have limited success in predicting human physiology, pathology, and therapeutic responses. Moreover, animal testing is facing increasing ethical and bureaucratic hurdles, while human cell cultures are limited in their ability to represent in vivo situations due to the lack of the tissue microenvironment, which may alter cellular responses. To overcome these struggles, organ cultures, especially those of complex organs such as the retina, can be used to study physiological reactions to substances or stressors. Human and animal organ cultures are now well established and recognized. This mini-review discusses how retinal organ cultures can be used to preserve tissue architecture more realistically and therefore better represent disease-related changes. It also shows how molecular biological, biochemical, and histological techniques can be combined to investigate how anatomical localization may alter cellular responses. Examples for the use of retinal organ cultures, including models to study age-related macular degeneration (AMD), retinitis pigmentosa (RP), central artery occlusion (CRAO), and glaucoma are presented, and their advantages and disadvantages are discussed. We conclude that organ cultures significantly improve our understanding of complex retinal diseases and may advance treatment testing without the need for animal testing.

scholarly journals Superior Properties of N-Acetylcysteine Ethyl Ester over N-Acetyl Cysteine to Prevent Retinal Pigment Epithelial Cells Oxidative Damage

2021 ◽  
Vol 22 (2) ◽  
pp. 600
Author(s):  
Gian Marco Tosi ◽  
Daniela Giustarini ◽  
Lorenzo Franci ◽  
Alberto Minetti ◽  
Francesco Imperatore ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Oxidative Damage ◽  
Ethyl Ester ◽  
Retinal Pigment ◽  
Developed Countries ◽  
Retinal Pigment Epithelial Cells ◽  
Age Related Macular Degeneration ◽  
Retinal Diseases ◽  
Rpe Cells ◽  
Age Related

Oxidative stress plays a key role in the pathophysiology of retinal diseases, including age-related macular degeneration (AMD) and diabetic retinopathy, which are the major causes of irreversible blindness in developed countries. An excess of reactive oxygen species (ROS) can directly cause functional and morphological impairments in retinal pigment epithelium (RPE), endothelial cells, and retinal ganglion cells. Antioxidants may represent a preventive/therapeutic strategy and reduce the risk of progression of AMD. Among antioxidants, N-acetyl-L-cysteine (NAC) is widely studied and has been proposed to have therapeutic benefit in treating AMD by mitigating oxidative damage in RPE. Here, we demonstrate that N-acetyl-L-cysteine ethyl ester (NACET), a lipophilic cell-permeable cysteine derivative, increases the viability in oxidative stressed RPE cells more efficiently than NAC by reacting directly and more rapidly with oxidizing agents, and that NACET, but not NAC, pretreatment predisposes RPE cells to oxidative stress resistance and increases the intracellular reduced glutathione (GSH) pool available to act as natural antioxidant defense. Moreover, we demonstrate the ability of NACET to increase GSH levels in rats’ eyes after oral administration. In conclusion, even if experiments in AMD animal models are still needed, our data suggest that NACET may play an important role in preventing and treating retinal diseases associated with oxidative stress, and may represent a valid and more efficient alternative to NAC in therapeutic protocols in which NAC has already shown promising results.

Die Zukunft der Anti-VEGF-A-Therapie

2021 ◽  
pp. 1-2
Author(s):  
Olaf Strauß
Keyword(s):  
Drug Delivery ◽  
Severe Infection ◽  
Posterior Segment ◽  
Age Related Macular Degeneration ◽  
Retinal Diseases ◽  
Sustained Delivery ◽  
Advantages And Disadvantages ◽  
Sustained Drug Delivery ◽  
Anti Vegf ◽  
Age Related

Anti-vascular endothelial growth factors (anti-VEGF) have become the most common treatment modality for many retinal diseases. These include neovascular age-related macular degeneration (n-AMD), proliferative diabetic retinopathy (PDR) and retinal vein occlusions (RVO). However, these drugs are administered via intravitreal injections that are associated with sight-threatening complications. The most feared of these complications is endophthalmitis, a severe infection of the eye with extremely poor visual outcomes. Patients with retinal diseases typically have to undergo multiple injections before achieving the desired therapeutic effect. Each injection incurs the risk of the sight-threatening complications. As such, there has been great interest in developing sustained delivery platforms for anti-VEGF agents to the posterior segment of the eye. In recent years, there have been various strategies that have been conceptualised. These include non-biodegradable implants, nano-formulations and hydrogels. In this review, the barriers of drug delivery to the posterior segment of the eye will be explained. The characteristics of an ideal sustained delivery platform will then be discussed. Finally, the current available strategies will be analysed with the above-mentioned characteristics in mind to determine the advantages and disadvantages of each sustained drug delivery modality. Through the above, this review attempts to provide an overview of the sustained delivery platforms in their various phases of development.

scholarly journals Development of a Fundus Image-Based Deep Learning Diagnostic Tool for Various Retinal Diseases

2021 ◽  
Vol 11 (5) ◽  
pp. 321
Author(s):  
Kyoung Min Kim ◽  
Tae-Young Heo ◽  
Aesul Kim ◽  
Joohee Kim ◽  
Kyu Jin Han ◽  
...  
Keyword(s):  
Network Models ◽  
Retinal Disease ◽  
Age Related Macular Degeneration ◽  
Diagnostic Tools ◽  
Retinal Images ◽  
Dense Layer ◽  
Retinal Diseases ◽  
Fundus Image ◽  
Neural Network Models ◽  
Age Related

Artificial intelligence (AI)-based diagnostic tools have been accepted in ophthalmology. The use of retinal images, such as fundus photographs, is a promising approach for the development of AI-based diagnostic platforms. Retinal pathologies usually occur in a broad spectrum of eye diseases, including neovascular or dry age-related macular degeneration, epiretinal membrane, rhegmatogenous retinal detachment, retinitis pigmentosa, macular hole, retinal vein occlusions, and diabetic retinopathy. Here, we report a fundus image-based AI model for differential diagnosis of retinal diseases. We classified retinal images with three convolutional neural network models: ResNet50, VGG19, and Inception v3. Furthermore, the performance of several dense (fully connected) layers was compared. The prediction accuracy for diagnosis of nine classes of eight retinal diseases and normal control was 87.42% in the ResNet50 model, which added a dense layer with 128 nodes. Furthermore, our AI tool augments ophthalmologist’s performance in the diagnosis of retinal disease. These results suggested that the fundus image-based AI tool is applicable for the medical diagnosis process of retinal diseases.

scholarly journals Impact of neovascular age-related macular degeneration: burden of patients receiving therapies in Japan

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shigeru Honda ◽  
Yasuo Yanagi ◽  
Hideki Koizumi ◽  
Yirong Chen ◽  
Satoru Tanaka ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Productivity Loss ◽  
Work Productivity ◽  
The Elderly ◽  
Developed Countries ◽  
Age Related Macular Degeneration ◽  
Resource Utilisation ◽  
Total Work ◽  
Healthcare Resource Utilisation ◽  
Age Related

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.

scholarly journals Carotenoid Profiling of Orange-Coloured Capsicums: In Search of High-Zeaxanthin Varieties for Eye Health

Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 84
Author(s):  
Rimjhim Agarwal ◽  
Hung T. Hong ◽  
Alice Hayward ◽  
Stephen Harper ◽  
Neena Mitter ◽  
...  
Keyword(s):  
Dietary Intake ◽  
Macular Degeneration ◽  
Developed Countries ◽  
Age Related Macular Degeneration ◽  
Daily Dietary Intake ◽  
Eye Health ◽  
Age Related ◽  
Rate Of Progression ◽  
Red Capsicum

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.

FUNCTIONAL METHODS OF EARLY DIAGNOSTICS OF AGE MACULAR DEGENERATION.(LITERATURE REVIEW)

2021 ◽  
Vol Special issue (2) ◽  
pp. 61-67
Author(s):  
Azamat Yusupov ◽  
◽  
Mukhiddin Ziyoviddinov ◽  
Shavkat Mukhanov ◽  
O.O. Sobirov
Keyword(s):  
Literature Review ◽  
Macular Degeneration ◽  
Contrast Sensitivity ◽  
Morphological Changes ◽  
Pigment Epithelium ◽  
Sensitivity Study ◽  
Age Related Macular Degeneration ◽  
Functional Diagnostics ◽  
Advantages And Disadvantages ◽  
Age Related

This article provides an unsystematic literature review devoted to analyzing the currently existing methods of functional diagnostics for age-related macular degeneration.The essence, advantages and disadvantages, and literature data on the use of such methods asphotostresstest, electrooculography, dark adaptation study, contrast sensitivity function assessment, light and color sensitivity study,electroretinographyand critical flicker fusion frequencyare described.Based on the analysis of literature data, itis shownthat currently, there is a need to searchfor informative and accessible methods of functional diagnostics in age-related macular degeneration, especially for its early diagnosis. The analysis has shown that the existing methods are mainly aimed either at fixing secondary morphological changes in the layer of pigment epithelial cells, at identifying the pathology of the pigment epithelium in conjunction with determining the function of photoreceptor elements, or at a comprehensive assessment of the structures of several layers of the retina. Keywords:age-related macular degeneration; methods of functional diagnostics; photostress test; electrooculography; contrast sensitivity

Therapeutic effects of a novel siRNA-based anti-VEGF (siVEGF) nanoball for the treatment of choroidal neovascularization

Nanoscale ◽  
2017 ◽  
Vol 9 (40) ◽  
pp. 15461-15469 ◽  
Author(s):  
Na-Kyung Ryoo ◽  
Jihwang Lee ◽  
Hyunjoo Lee ◽  
Hye Kyoung Hong ◽  
Hyejin Kim ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Choroidal Neovascularization ◽  
Developed Countries ◽  
Age Related Macular Degeneration ◽  
Therapeutic Effects ◽  
Anti Vegf ◽  
Age Related

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

scholarly journals Introduction to the multi-author review on macular degeneration

2020 ◽  
Vol 77 (5) ◽  
pp. 779-780 ◽  
Author(s):  
Anu Kauppinen
Keyword(s):  
Macular Degeneration ◽  
Vision Loss ◽  
The Elderly ◽  
Developed Countries ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Severe Vision Loss ◽  
Author Review ◽  
Dry Amd ◽  
Endothelial Growth Factor

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.

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