37,540 results match your criteria retinal pigment

A vicious cycle of bisretinoid formation and oxidation relevant to recessive Stargardt disease.

J Biol Chem 2021 Jan 7;296:100259. Epub 2021 Jan 7.

Department of Ophthalmology, Columbia University Medical Center, New York, New York, USA; Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York, USA. Electronic address:

The ability of iron to transfer electrons enables the contribution of this metal to a variety of cellular activities even as the redox properties of iron are also responsible for the generation of hydroxyl radicals (OH), the most destructive of the reactive oxygen species. We previously showed that iron can promote the oxidation of bisretinoid by generating highly reactive hydroxyl radical (OH). Now we report that preservation of iron regulation in the retina is not sufficient to prevent iron-induced bisretinoid oxidative degradation when blood iron levels are elevated in liver-specific hepcidin knockout mice. Read More

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January 2021

Multimodal imaging characteristics in eyes with vitreoretinal lymphoma treated with intravitreal rituximab.

Int Ophthalmol 2021 Apr 8. Epub 2021 Apr 8.

Medical Research Foundation, Shri Bhagwan Mahavir Vitreo-Retinal Services, Sankara Nethralaya, 18 College Road, Chennai, 600006, Tamilnadu, India.

Purpose: To characterize the imaging features in eyes with vitreoretinal lymphoma (VRL) using ultra-widefield fundus photography (UWF-FP), swept-source optical coherence tomography (SSOCT) and fundus autofluorescence (FAF) that are correlated to ongoing treatment with intravitreal Rituximab(IVR).

Methods: Retrospective observational imaging-based study of 15 treatment-naive eyes with VRL treated with IVR. All patients with primary VRL underwent vitreous biopsy using 23/25G microincision vitrectomy system for confirmation of diagnosis. Read More

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EYS mutations and implementation of minigene assay for variant classification in EYS-associated retinitis pigmentosa in northern Sweden.

Sci Rep 2021 Apr 8;11(1):7696. Epub 2021 Apr 8.

Medical Biosciences/Medical and Clinical Genetics, University of Umeå, 901 87, Umeå, Sweden.

Retinitis pigmentosa (RP) is a clinically and genetically heterogeneous group of inherited retinal degenerations. The ortholog of Drosophila eyes shut/spacemaker, EYS on chromosome 6q12 is a major genetic cause of recessive RP worldwide, with prevalence of 5 to 30%. In this study, by using targeted NGS, MLPA and Sanger sequencing we uncovered the EYS gene as one of the most common genetic cause of autosomal recessive RP in northern Sweden accounting for at least 16%. Read More

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Subretinal Rather Than Intravitreal Adeno-Associated Virus-Mediated Delivery of a Complement Alternative Pathway Inhibitor Is Effective in a Mouse Model of RPE Damage.

Invest Ophthalmol Vis Sci 2021 Apr;62(4):11

Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States.

Purpose: The risk for age-related macular degeneration has been tied to an overactive complement system. Despite combined attempts by academia and industry to develop therapeutics that modulate the complement response, particularly in the late geographic atrophy form of advanced AMD, to date, there is no effective treatment. We have previously demonstrated that pathology in the smoke-induced ocular pathology (SIOP) model, a model with similarities to dry AMD, is dependent on activation of the alternative complement pathway and that a novel complement activation site targeted inhibitor of the alternative pathway can be delivered to ocular tissues via an adeno-associated virus (AAV). Read More

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Long-term effects of human induced pluripotent stem cell-derived retinal cell transplantation in Pde6b knockout rats.

Exp Mol Med 2021 Apr 8. Epub 2021 Apr 8.

Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea.

Retinal degenerative disorders, including age-related macular degeneration and retinitis pigmentosa (RP), are characterized by the irreversible loss of photoreceptor cells and retinal pigment epithelial (RPE) cells; however, the long-term effect of implanting both human induced pluripotent stem cell (hiPSC)-derived RPE and photoreceptor for retinal regeneration has not yet been investigated. In this study, we evaluated the long-term effects of hiPSC-derived RPE and photoreceptor cell transplantation in Pde6b knockout rats to study RP; cells were injected into the subretinal space of the right eyes of rats before the appearance of signs of retinal degeneration at 2-3 weeks of age. Ten months after transplantation, we evaluated the cells using fundus photography, optical coherence tomography, and histological evaluation, and no abnormal cell proliferation was observed. Read More

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Investigation of the effectiveness of a new portable 'cryopen' probe for cryotherapy (CryoTreq®).

Int J Retina Vitreous 2021 Apr 7;7(1):28. Epub 2021 Apr 7.

Dept. Ophthalmology UZ Leuven, Herestraat 49, 3000, Leuven, Belgium.

Background: To test the effectiveness of a new, innovative, single-use handheld 'cryopen' (CryoTreq®), which has been developed and marketed by Vitreq.

Methods: Animal testing of cryopexy using the Cryotreq ® in two pig eyes was performed.

Results: The biological effects of cryopexy were observed. Read More

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Design and Characterization of Biomimetic Kerateine Aerogel-Electrospun Polycaprolactone Scaffolds for Retinal Cell Culture.

Ann Biomed Eng 2021 Apr 6. Epub 2021 Apr 6.

Department of Chemical, Paper and Biomedical Engineering, Miami University, 650 East High Street, Oxford, OH, 45056, USA.

Age-related macular degeneration (AMD) is a retinal disease that affects 196 million people and causes nearly 9% of blindness worldwide. While several pharmacological approaches slow the effects of AMD, in our opinion, cell-based strategies offer the most likely path to a cure. We describe the design and initial characterization of a kerateine (obtained by reductive extraction from keratin proteins) aerogel-electrospun polycaprolactone fiber scaffold system. Read More

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Mitochondria-dependent phase separation of disease-relevant proteins drives pathological features of age-related macular degeneration.

JCI Insight 2021 Apr 6. Epub 2021 Apr 6.

Department of Ophthalmology, University of California, San Francisco, San Francisco, United States of America.

Age-related macular degeneration (AMD) damages the retinal pigment epithelium (RPE), the tissue that safeguards photoreceptor health, leading to irreversible vision loss. Polymorphisms in cholesterol and complement genes are implicated in AMD, yet mechanisms linking risk variants to RPE injury remain unclear. We sought to determine how allelic variants in the apolipoprotein E cholesterol transporter modulate RPE homeostasis and function. Read More

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LncRNA SNHG4 sponges miR-200b to inhibit cell apoptosis in diabetic retinopathy.

Arch Physiol Biochem 2021 Apr 6:1-6. Epub 2021 Apr 6.

Department of Ophthalmology, The First Affiliated Hospital of Bengbu Medical College, Bengbu City, People's Republic of China.

This study aimed to investigate the role of long non-coding RNA (lncRNA) small nucleolar RNA host gene 4 (SNHG4) in diabetic retinopathy (DR). We found that SNHG4 was downregulated in DR. SNHG4 could directly interact with miR-200b, while overexpression of miR-200b did not affect the expression of SNHG4 in human retinal pigment epithelial cells ARPE-19. Read More

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Measurement of drusen and their correlation with visual symptoms in patients affected by age-related macular degeneration.

Arch Ital Biol 2020 Dec;158(3-4):82-104

Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa (Italy) - Email:

Age-related macular degeneration (AMD) is a common retinal disorder, which became more and more prevalent in the last decades. AMD is now the most prevalent cause of blindness in the western world. The disorder is classified into two phenotypes named dry and wet AMD. Read More

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December 2020

Cone-Enriched Cultures from the Retina of Chicken Embryos to Study Rod to Cone Cellular Interactions.

J Vis Exp 2021 Mar 20(169). Epub 2021 Mar 20.

Department of Genetics - Sorbonne Université, INSERM, CNRS, Institut de la Vision;

Human daytime vision relies on the function of cone photoreceptors at the center of the retina, the fovea. Patients suffering from the most prevalent form of inherited retinal degeneration, retinitis pigmentosa, lose night vision because of mutation driven loss of rod photoreceptors, a phenomenon followed by a progressive loss of function and death of cones leading to blindness. Geneticists have identified many genes with mutations causing this disease, but the first mutations identified questioned the mechanisms of secondary cone degeneration and how a dominant mutation in the rhodopsin gene encoding for the visual pigment expressed exclusively in rods can trigger cone degeneration. Read More

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Bilateral retinal toxicity as a result of poisoning with pure iodine.

Rom J Ophthalmol 2021 Jan-Mar;65(1):73-75

Ophthalmology Department, University of Health Sciences Ulucanlar Eye Training and Research Hospital, Ankara, Turkey.

Iodine is an essential mineral that is necessary for the synthesis of thyroid hormones, which can cause many diseases in the body. The application of adding potassium iodate to table salts started in Turkey in 1998. High doses of iodate cause retinal toxicity, leading to significant vision loss. Read More

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Influences of advanced glycosylation end products on the inner blood-retinal barrier in a co-culture cell model .

Open Life Sci 2020 24;15(1):619-628. Epub 2020 Aug 24.

Department of Ophthalmology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610072, Sichuan Province, People's Republic of China.

Advanced glycosylation end products (AGEs) are harmful factors that can damage the inner blood-retinal barrier (iBRB). Rat retinal microvascular endothelial cells (RMECs) were isolated and cultured, and identified by anti-CD31 and von Willebrand factor polyclonal antibodies. Similarly, rat retinal Müller glial cells (RMGCs) were identified by H&E staining and with antibodies of glial fibrillary acidic protein and glutamine synthetase. Read More

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Iron Accumulation and Lipid Peroxidation in the Aging Retina: Implication of Ferroptosis in Age-Related Macular Degeneration.

Aging Dis 2021 Apr 1;12(2):529-551. Epub 2021 Apr 1.

1Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China.

Iron is an essential component in many biological processes in the human body. It is critical for the visual phototransduction cascade in the retina. However, excess iron can be toxic. Read More

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Build me up optic cup: Intrinsic and extrinsic mechanisms of vertebrate eye morphogenesis.

Dev Biol 2021 Mar 31. Epub 2021 Mar 31.

Department of Human Genetics, University of Utah, Salt Lake City, UT, 84112, USA. Electronic address:

The basic structure of the eye, which is crucial for visual function, is established during the embryonic process of optic cup morphogenesis. Molecular pathways of specification and patterning are integrated with spatially distinct cell and tissue shape changes to generate the eye, with discrete domains and structural features: retina and retinal pigment epithelium enwrap the lens, and the optic fissure occupies the ventral surface of the eye and optic stalk. Interest in the underlying cell biology of eye morphogenesis has led to a growing body of work, combining molecular genetics and imaging to quantify cellular processes such as adhesion and actomyosin activity. Read More

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Retinal Pigment Epithelium and Neural Retinal Progenitors Interact Via Semaphorin 6D to Facilitate Optic Cup Morphogenesis.

eNeuro 2021 Apr 2. Epub 2021 Apr 2.

University of Calgary, Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute

Cell movement propels embryonic tissues to acquire shapes required for mature function. The movements are driven both by acto-myosin signaling, and by cells interacting with the extracellular matrix. Unknown is whether cell-cell interactions within a tissue are also required, and the molecular mechanisms by which such communication might occur. Read More

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A ROCK Inhibitor Promotes Graft Survival during Transplantation of iPS-Cell-Derived Retinal Cells.

Int J Mol Sci 2021 Mar 22;22(6). Epub 2021 Mar 22.

RIKEN Center for Biosystems Dynamics Research, Laboratory for Retinal Regeneration, Kobe 650-0047, Japan.

Currently, retinal pigment epithelium (RPE) transplantation includes sheet and single-cell transplantation, the latter of which includes cell death and may be highly immunogenic, and there are some issues to be improved in single-cell transplantation. Y-27632 is an inhibitor of Rho-associated protein kinase (ROCK), the downstream kinase of Rho. We herein investigated the effect of Y-27632 in vitro on retinal pigment epithelium derived from induced pluripotent stem cells (iPS-RPE cells), and also its effects in vivo on the transplantation of iPS-RPE cell suspensions. Read More

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Defining Phenotype, Tropism, and Retinal Gene Therapy Using Adeno-Associated Viral Vectors (AAVs) in New-Born Brown Norway Rats with a Spontaneous Mutation in .

Int J Mol Sci 2021 Mar 30;22(7). Epub 2021 Mar 30.

Department of Ophthalmology, Leiden University Medical Center (LUMC), Albinusdreef 2, 2333 ZA Leiden, The Netherlands.

Mutations in the Crumbs homologue 1 () gene cause inherited retinal dystrophies, such as early-onset retinitis pigmentosa and Leber congenital amaurosis. A Brown Norway rat strain was reported with a spontaneous insertion-deletion (indel) mutation in exon 6 of . It has been reported that these mutant rats show vascular abnormalities associated with retinal telangiectasia and possess an early-onset retinal degenerative phenotype with outer limiting membrane breaks and focal loss of retinal lamination at 2 months of age. Read More

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Antioxidant Activity and Neuroprotective Role of Docosahexaenoic Acid (DHA) Supplementation in Eye Diseases That Can Lead to Blindness: A Narrative Review.

Antioxidants (Basel) 2021 Mar 5;10(3). Epub 2021 Mar 5.

Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, E-08028 Barcelona, Spain.

The objective of this narrative review is to provide updated evidence, based on data from experimental and clinical studies, of the prominent role of omega-3 polyunsaturated fatty acids (n-3 PUFAs) for a number of crucial mechanisms involved in counteracting cell damage induced by oxidative stress in eye diseases. This article is focused on the antioxidant and neuroprotective effects of docosahexaenoic acid (DHA), which have been assessed in different experimental models and clinical studies, particularly in proliferative diabetic retinopathy, age-related macular degeneration and glaucoma that are the most common eye diseases leading to severe vision loss. The mechanisms involved in the role of DHA in protecting human retinal pigment epithelial cells from oxidative stress as well as the interaction with glutathione (GSH) are also described. Read More

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Visual Parameters and Retinal Morphology for Polypoidal Choroidal Vasculopathy Pre- and Post-Intravitreal Ranibizumab with or without Photodynamic Therapy: A Short-Term Prospective Study.

Int J Environ Res Public Health 2021 Mar 4;18(5). Epub 2021 Mar 4.

Department of Ophthalmology, Hospital Shah Alam, Persiaran Kayangan, Seksyen 7, Shah Alam 40000, Malaysia.

The objective of this study was to compare visual parameters and retinal layers' morphology pre-treatment (baseline) and 6 months post-treatment in polypoidal choroidal vasculopathy (PCV) eyes. A single centre, longitudinal, prospective study was conducted at a public tertiary hospital of Malaysia. Visual parameters including distance and near visual acuity (DVA and NVA), contrast sensitivity (CS), reading speed (RS), and different qualitative and quantitative optical coherence tomography (OCT) parameters were evaluated pre- and 6 months post-treatment. Read More

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Enhanced Transport and Permeation of a Polymeric Nanocarrier across the Retina by Mixing with ATP upon Intravitreal Injection.

Pharmaceutics 2021 Mar 29;13(4). Epub 2021 Mar 29.

School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea.

The outer part of the retina pigment epithelium (RPE) in the retina is the main site of neovascularization associated with retinal diseases. However, various obstacles interrupt the delivery of medicines across the RPE, mainly due to the well-developed tight junctions in the RPE. Currently, there is no practical formulation to overcome this issue. Read More

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Products of Docosahexaenoate Oxidation as Contributors to Photosensitising Properties of Retinal Lipofuscin.

Int J Mol Sci 2021 Mar 29;22(7). Epub 2021 Mar 29.

Institute of Biology, Pedagogical University, 30-084 Kraków, Poland.

Retinal lipofuscin which accumulates with age in the retinal pigment epithelium (RPE) is subjected to daily exposures to high fluxes of visible light and exhibits potent photosensitising properties; however, the molecules responsible for its photoreactivity remain unknown. Here, we demonstrate that autooxidation of docosahexaenoate (DHE) leads to the formation of products absorbing, in addition to UVB and UVA light, also visible light. The products of DHE oxidation exhibit potent photosensitising properties similar to photosensitising properties of lipofuscin, including generation of an excited triplet state with similar characteristics as the lipofuscin triplet state, and photosensitised formation of singlet oxygen and superoxide. Read More

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Cell-Matrix Interactions in the Eye: From Cornea to Choroid.

Cells 2021 Mar 20;10(3). Epub 2021 Mar 20.

Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa Hospitals & Clinics, Iowa City, IA 52242, USA.

The extracellular matrix (ECM) plays a crucial role in all parts of the eye, from maintaining clarity and hydration of the cornea and vitreous to regulating angiogenesis, intraocular pressure maintenance, and vascular signaling. This review focuses on the interactions of the ECM for homeostasis of normal physiologic functions of the cornea, vitreous, retina, retinal pigment epithelium, Bruch's membrane, and choroid as well as trabecular meshwork, optic nerve, conjunctiva and tenon's layer as it relates to glaucoma. A variety of pathways and key factors related to ECM in the eye are discussed, including but not limited to those related to transforming growth factor-β, vascular endothelial growth factor, basic-fibroblastic growth factor, connective tissue growth factor, matrix metalloproteinases (including MMP-2 and MMP-9, and MMP-14), collagen IV, fibronectin, elastin, canonical signaling, integrins, and endothelial morphogenesis consistent of cellular activation-tubulogenesis and cellular differentiation-stabilization. Read More

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Metabolism in the Zebrafish Retina.

J Dev Biol 2021 Mar 15;9(1). Epub 2021 Mar 15.

Institute of Ophthalmology, University College London, London EC1V 9EL, UK.

Retinal photoreceptors are amongst the most metabolically active cells in the body, consuming more glucose as a metabolic substrate than even the brain. This ensures that there is sufficient energy to establish and maintain photoreceptor functions during and after their differentiation. Such high dependence on glucose metabolism is conserved across vertebrates, including zebrafish from early larval through to adult retinal stages. Read More

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Regulation of Endothelium-Reticulum-Stress-Mediated Apoptotic Cell Death by a Polymethoxylated Flavone, Nobiletin, Through the Inhibition of Nuclear Translocation of Glyceraldehyde 3-Phosphate Dehydrogenase in Retinal Müller Cells.

Cells 2021 Mar 17;10(3). Epub 2021 Mar 17.

Faculty of Pharma-Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan.

In the early stages of diabetic retinopathy (DR), subtle biochemical and functional alterations occur in Müller cells, which are one of the components of the blood-retinal barrier (BRB). Müller cells are the principal glia of the retina and have shown a strong involvement in the maintenance of homeostasis and the development of retinal tissue. Their functional abnormalities and eventual loss have been correlated with a decrease in the tight junctions between endothelial cells and a consequent breakdown of the BRB, leading to the development of DR. Read More

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Replacement of polyps with type 1 macular neovascularization in polypoidal choroidal vasculopathy imaged with swept source OCT angiography.

Am J Ophthalmol Case Rep 2021 Jun 11;22:101057. Epub 2021 Mar 11.

Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA.

Purpose: To investigate the morphological changes of polyps in eyes with polypoidal choroidal vasculopathy (PCV) after treatment with vascular endothelial growth factor (VEGF) inhibitors using swept source optical coherence tomography angiography (SS-OCTA).

Observations: Following anti-VEGF therapy, polyps were found to evolve into typical type 1 macular neovascularization (MNV) in five eyes. In all of these five eyes, a polypoidal lesion was detected adjacent to a serous or hemorrhagic retinal pigment epithelial detachment (PED). Read More

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Immunotherapy-Resistant Vitreoretinal Metastatic Melanoma.

Ocul Oncol Pathol 2021 Mar 3;7(1):62-65. Epub 2020 Nov 3.

Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA.

Purpose: To describe 2 cases of vitreoretinal metastases in patients treated with immunotherapy for metastatic melanoma.

Methods: Retrospective case series.

Results: We pre-sent 2 patients with metastatic melanoma treated with systemic immunotherapy with subsequent development of ocular vitreoretinal metastasis. Read More

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OCT-GAN: single step shadow and noise removal from optical coherence tomography images of the human optic nerve head.

Biomed Opt Express 2021 Mar 19;12(3):1482-1498. Epub 2021 Feb 19.

Ophthalmic Engineering and Innovation Laboratory (OEIL), Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.

Speckle noise and retinal shadows within OCT B-scans occlude important edges, fine textures and deep tissues, preventing accurate and robust diagnosis by algorithms and clinicians. We developed a single process that successfully removed both noise and retinal shadows from unseen single-frame B-scans within 10.4ms. Read More

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Integrating adaptive optics-SLO and OCT for multimodal visualization of the human retinal pigment epithelial mosaic.

Biomed Opt Express 2021 Mar 17;12(3):1449-1466. Epub 2021 Feb 17.

National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.

In vivo imaging of human retinal pigment epithelial (RPE) cells has been demonstrated through multiple adaptive optics (AO)-based modalities. However, whether consistent and complete information regarding the cellular structure of the RPE mosaic is obtained across these modalities remains uncertain due to limited comparisons performed in the same eye. Here, an imaging platform combining multimodal AO-scanning light ophthalmoscopy (AO-SLO) with AO-optical coherence tomography (AO-OCT) is developed to make a side-by-side comparison of the same RPE cells imaged across four modalities: AO-darkfield, AO-enhanced indocyanine green (AO-ICG), AO-infrared autofluorescence (AO-IRAF), and AO-OCT. Read More

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Tsg101 Is Necessary for the Establishment and Maintenance of Mouse Retinal Pigment Epithelial Cell Polarity.

Mol Cells 2021 Mar;44(3):168-178

Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.

The retinal pigment epithelium (RPE) forms a monolayer sheet separating the retina and choroid in vertebrate eyes. The polarized nature of RPE is maintained by distributing membrane proteins differentially along apico-basal axis. We found the distributions of these proteins differ in embryonic, post-natal, and mature mouse RPE, suggesting developmental regulation of protein trafficking. Read More

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