scholarly journals Photoacoustic Ophthalmoscopy: Principle, Application, and Future Directions

2018 ◽  
Vol 4 (12) ◽  
pp. 149 ◽  
Author(s):  
Van Nguyen ◽  
Yannis Paulus
Keyword(s):  
Vision Loss ◽  
Imaging System ◽  
Imaging Techniques ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Photoacoustic Microscopy ◽  
Ocular Diseases ◽  
Depth Of Penetration ◽  
Microscopy Imaging ◽  
Ocular Imaging

Photoacoustic ophthalmoscopy (PAOM) is a novel, hybrid, non-ionizing, and non-invasive imaging technology that has been used to assess the retina. PAOM can provide both anatomic and functional retinal characterizations with high resolution, high sensitivity, high contrast, and a high depth of penetration. Thus, ocular diseases can be precisely detected and visualized at earlier stages, resulting in an improved understanding of pathophysiology, improved management, and the improved monitoring of retinal treatment to prevent vision loss. To better visualize ocular components such as retinal vessels, choroidal vessels, choroidal neovascularization, retinal neovascularization, and the retinal pigment epithelium, an advanced multimodal ocular imaging platform has been developed by a combination of PAOM with other optical imaging techniques such as optical coherence tomography (OCT), scanning laser ophthalmoscopy (SLO), and fluorescence microscopy. The multimodal images can be acquired from a single imaging system and co-registered on the same image plane, enabling an improved evaluation of disease. In this review, the potential application of photoacoustic ophthalmoscopy in both research and clinical diagnosis are discussed as a medical screening technique for the visualization of various ocular diseases. The basic principle and requirements of photoacoustic ocular imaging are introduced. Then, various photoacoustic microscopy imaging systems of the retina in animals are presented. Finally, the future development of PAOM and multimodal imaging is discussed.

Automated segmentation and quantitative study of retinal pigment epithelium cells for photoacoustic microscopy imaging

2017 ◽  
Vol 15 (5) ◽  
pp. 051101-51105
Author(s):  
Lin Li Lin Li ◽  
Qian Li Qian Li ◽  
Cuixia Dai Cuixia Dai ◽  
Qingliang Zhao Qingliang Zhao ◽  
Tianhao Yu Tianhao Yu ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Quantitative Study ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Automated Segmentation ◽  
Photoacoustic Microscopy ◽  
Microscopy Imaging ◽  
Retinal Pigment Epithelium Cells ◽  
Epithelium Cells

scholarly journals Role of amyloid β-peptide in the pathogenesis of age-related macular degeneration

2021 ◽  
Vol 6 (1) ◽  
pp. e000774
Author(s):  
Minwei Wang ◽  
Shiqi Su ◽  
Shaoyun Jiang ◽  
Xinghuai Sun ◽  
Jiantao Wang
Keyword(s):  
Mitochondrial Dysfunction ◽  
Macular Degeneration ◽  
Vision Loss ◽  
Cell Structure ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Amyloid Β ◽  
Age Related Macular Degeneration ◽  
Amyloid Β Peptide ◽  
Age Related

Age-related macular degeneration (AMD) is the most common eye disease in elderly patients, which could lead to irreversible vision loss and blindness. Increasing evidence indicates that amyloid β-peptide (Aβ) might be associated with the pathogenesis of AMD. In this review, we would like to summarise the current findings in this field. The literature search was done from 1995 to Feb, 2021 with following keywords, ‘Amyloid β-peptide and age-related macular degeneration’, ‘Inflammation and age-related macular degeneration’, ‘Angiogenesis and age-related macular degeneration’, ‘Actin cytoskeleton and amyloid β-peptide’, ‘Mitochondrial dysfunction and amyloid β-peptide’, ‘Ribosomal dysregulation and amyloid β-peptide’ using search engines Pubmed, Google Scholar and Web of Science. Aβ congregates in subretinal drusen of patients with AMD and participates in the pathogenesis of AMD through enhancing inflammatory activity, inducing mitochondrial dysfunction, altering ribosomal function, regulating the lysosomal pathway, affecting RNA splicing, modulating angiogenesis and modifying cell structure in AMD. The methods targeting Aβ are shown to inhibit inflammatory signalling pathway and restore the function of retinal pigment epithelium cells and photoreceptor cells in the subretinal region. Targeting Aβ may provide a novel therapeutic strategy for AMD.

scholarly journals A human model of Batten disease shows role of CLN3 in phagocytosis at the photoreceptor–RPE interface

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Cynthia Tang ◽  
Jimin Han ◽  
Sonal Dalvi ◽  
Kannan Manian ◽  
Lauren Winschel ◽  
...  
Keyword(s):  
Photoreceptor Cell ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Cell Loss ◽  
Human Model ◽  
Lysosomal Storage ◽  
Rpe Cells ◽  
Cln3 Disease

AbstractMutations in CLN3 lead to photoreceptor cell loss in CLN3 disease, a lysosomal storage disorder characterized by childhood-onset vision loss, neurological impairment, and premature death. However, how CLN3 mutations cause photoreceptor cell death is not known. Here, we show that CLN3 is required for phagocytosis of photoreceptor outer segment (POS) by retinal pigment epithelium (RPE) cells, a cellular process essential for photoreceptor survival. Specifically, a proportion of CLN3 in human, mouse, and iPSC-RPE cells localized to RPE microvilli, the site of POS phagocytosis. Furthermore, patient-derived CLN3 disease iPSC-RPE cells showed decreased RPE microvilli density and reduced POS binding and ingestion. Notably, POS phagocytosis defect in CLN3 disease iPSC-RPE cells could be rescued by wild-type CLN3 gene supplementation. Altogether, these results illustrate a novel role of CLN3 in regulating POS phagocytosis and suggest a contribution of primary RPE dysfunction for photoreceptor cell loss in CLN3 disease that can be targeted by gene therapy.

scholarly journals Giant Idiopathic Angioid Streaks

2020 ◽  
Author(s):  
Brijesh Takkar ◽  
Anubha Rathi ◽  
Pradeep Venkatesh ◽  
Atul Kumar
Keyword(s):  
Imaging Techniques ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Young Male ◽  
Significant Finding ◽  
Angioid Streaks ◽  
Retinal Hemorrhages ◽  
Swept Source ◽  
Steroid Abuse ◽  
Membrane Complex

Purpose: To present a case of gigantic idiopathic angioid streaks. Case Report: A young male presented with macular choroidal neovascular membrane (CNVM) and peripheral retinal hemorrhages secondary to angioid streaks. Swept source optical coherence tomography (SSOCT) and ultrawide field imaging were performed. The latter revealed extension of the angioid streaks up to the equator in both eyes. SSOCT showed breaks in the retinal pigment epithelium-Bruch’s membrane complex in the area of peripheral retinal hemorrhages. The patient was extensively worked up for systemic associations, and the only significant finding was a long history of steroid abuse in the past. Conclusion: Advanced imaging techniques helped to diagnose angioid streaks in this patient. The possible role of steroid abuse in accentuating the presentation of angioid streaks may be explored further.

scholarly journals PGC-1α Protects RPE Cells of the Aging Retina against Oxidative Stress-Induced Degeneration through the Regulation of Senescence and Mitochondrial Quality Control. The Significance for AMD Pathogenesis

2018 ◽  
Vol 19 (8) ◽  
pp. 2317 ◽  
Author(s):  
Kai Kaarniranta ◽  
Jakub Kajdanek ◽  
Jan Morawiec ◽  
Elzbieta Pawlowska ◽  
Janusz Blasiak
Keyword(s):  
Oxidative Stress ◽  
Cellular Senescence ◽  
Mitochondrial Biogenesis ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Sirtuin 1 ◽  
Age Related Macular Degeneration ◽  
Rpe Cells ◽  
Age Related

PGC-1α (peroxisome proliferator-activated receptor gamma coactivator 1-alpha) is a transcriptional coactivator of many genes involved in energy management and mitochondrial biogenesis. PGC-1α expression is associated with cellular senescence, organismal aging, and many age-related diseases, including AMD (age-related macular degeneration), an important global issue concerning vision loss. We and others have developed a model of AMD pathogenesis, in which stress-induced senescence of retinal pigment epithelium (RPE) cells leads to AMD-related pathological changes. PGC-1α can decrease oxidative stress, a key factor of AMD pathogenesis related to senescence, through upregulation of antioxidant enzymes and DNA damage response. PGC-1α is an important regulator of VEGF (vascular endothelial growth factor), which is targeted in the therapy of wet AMD, the most devastating form of AMD. Dysfunction of mitochondria induces cellular senescence associated with AMD pathogenesis. PGC-1α can improve mitochondrial biogenesis and negatively regulate senescence, although this function of PGC-1α in AMD needs further studies. Post-translational modifications of PGC-1α by AMPK (AMP kinase) and SIRT1 (sirtuin 1) are crucial for its activation and important in AMD pathogenesis.

The Effects of Indocyanine Green Dye-Enhanced Photocoagulation on the Blood Flow in the Choriocapillaris and the Choroidal Neovascularization (CNV)

2000 ◽  
Author(s):  
C. von Kerczek ◽  
L. Zhu ◽  
A. Ernest ◽  
C. Eggleton ◽  
L. D. T. Topoleski ◽  
...  
Keyword(s):  
Laser Treatment ◽  
Choroidal Neovascularization ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
The United States ◽  
Age Related Macular Degeneration ◽  
Central Vision ◽  
Age Related ◽  
Direct Laser

Abstract Age-related macular degeneration (AMD) is the most common cause of vision loss in patients aged 65 years and older in the United States. In the majority of cases, the loss of central vision is secondary to exudative changes and fibrovascular scarring following choroidal neovascularization (CNV). Prompt laser treatment is recommended [Asrani et al., 1996; Macular Photocoagulation Study Group, 1993; Schneider et al, 1998]. However, direct laser treatment to the entire subfoveal lesion is almost invariably associated with immediate loss of central vision. Loss of central vision may be due to direct damage to foveal photoreceptors and retinal pigment epithelium or from damage to the nerve fiber layer serving foveal function [Han et al., 1988].

Multimodal Retinal Imaging in Spinocerebellar Ataxia Type 1 Maculopathy

2021 ◽  
Vol 4 ◽  
pp. 2
Author(s):  
Mirriam Mikhail ◽  
Netan Choudhry
Keyword(s):  
Spinocerebellar Ataxia ◽  
Vision Loss ◽  
Retinal Pigment ◽  
Fundus Photography ◽  
Spinocerebellar Ataxia Type ◽  
Macular Dystrophy ◽  
Spinocerebellar Ataxia Type 1 ◽  
Imaging Results ◽  
Ocular Imaging

Objectives: The objective of the study was to investigate and report the multimodal ocular imaging findings associated with spinocerebellar ataxia type 1 (SCA 1) associated maculopathy. Methods: A full ophthalmologic assessment was completed in a 70-year-old male with confirmed SCA1 and noted progressive bilateral vision loss. Investigations included dilated fundus examination, full-field electroretinography, and swept-source optical coherence tomography (OCT). Results: On neurologic and ophthalmologic examination, he was found to have hypermetric saccades, horizontal nystagmus, and reduced color vision bilaterally. His best-corrected visual acuity was confirmed to be 20/80 OD and 20/100 OS at the time of consultation. Initial fundus photography was most notable for bilateral hypopigmentation of the fovea. Corresponding OCT imaging demonstrated an attenuation of the ellipsoid zone, in keeping with photoreceptor loss. Conclusion: The ocular imaging results suggest that the vision loss in the presented case occurred in the context of pigmentary macular dystrophy secondary to photoreceptor dysfunction and retinal pigment epithelial degeneration. This association offers an explanation with respect to the progressive vision loss, but further analyses would be required to determine the temporal correlation of clinical symptoms with imaging abnormalities. These findings suggest that SCA1 be considered as a potential cause for vision impairment, with possible benefits of visual assessment at the time of diagnosis.

Bruch’s membrane pathology: A mechanistic perspective

2020 ◽  
Vol 30 (6) ◽  
pp. 1195-1206 ◽  
Author(s):  
Aishwarya Murali ◽  
Subramanian Krishnakumar ◽  
Anuradha Subramanian ◽  
Sowmya Parameswaran
Keyword(s):  
Extracellular Matrix ◽  
Retinal Pigment Epithelium ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Vital Role ◽  
Age Related Macular Degeneration ◽  
Ocular Diseases ◽  
Bruch's Membrane ◽  
Bruch’S Membrane ◽  
Age Related

Bruch’s membrane, an extracellular matrix located between the retinal pigment epithelium and the choroid, plays a vital role as structural and functional support to the retinal pigment epithelium. Dysfunction of Bruch’s membrane in both age-related macular degeneration and other ocular diseases is caused mostly by extracellular matrix degeneration, deposit formation, and angiogenesis. Although these factors are dealt in greater detail with respect to the cells that are degenerated such as the retinal pigment epithelium and the endothelial cells, the pathology involving the Bruch’s membrane is often underrated. Since in most of the macular degenerations early degenerative changes are also observed in the Bruch’s membrane, addressing only the cellular component without the underlying membrane will not yield an ideal clinical benefit. This review aims to discuss the factors and the mechanisms affecting the integrity of the Bruch’s membrane, which would aid in developing an effective therapy for these pathologies.

scholarly journals Expression of Pro-Angiogenic Markers Is Enhanced by Blue Light in Human RPE Cells

Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1154 ◽  
Author(s):  
Concetta Scimone ◽  
Simona Alibrandi ◽  
Sergio Zaccaria Scalinci ◽  
Edoardo Trovato Battagliola ◽  
Rosalia D’Angelo ◽  
...  
Keyword(s):  
Blue Light ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
R Package ◽  
Rpe Cells ◽  
Inherited Retinal Dystrophies ◽  
Retinal Dystrophies ◽  
Increased Risk ◽  
Angiogenic Markers

Inherited retinal dystrophies are characterized by photoreceptor death. Oxidative stress usually occurs, increasing vision loss, and oxidative damage is often reported in retinitis pigmentosa (RP). More than 300 genes have been reported as RP causing. In contrast, choroidal neovascularization (CNV) only occasionally develops in the late stages of RP. We herein study the regulation of RP causative genes that are likely linked to CNV onset under oxidative conditions. We studied how the endogenous adduct N-retinylidene-N-retinylethanolamine (A2E) affects the expression of angiogenic markers in human retinal pigment epithelium (H-RPE) cells and a possible correlation with RP-causing genes. H-RPE cells were exposed to A2E and blue light for 3 and 6h. By transcriptome analysis, genes differentially expressed between A2E-treated cells and untreated ones were detected. The quantification of differential gene expression was performed by the Limma R package. Enrichment pathway analysis by the FunRich tool and gene prioritization by ToppGene allowed us to identify dysregulated genes involved in angiogenesis and linked to RP development. Two RP causative genes, AHR and ROM1, can be associated with an increased risk of CNV development. Genetic analysis of RP patients affected by CNV will confirm this hypothesis.

scholarly journals Inhibition of mitochondrial fission preserves photoreceptors after retinal detachment

2017 ◽  
Author(s):  
Xiangjun She ◽  
Xinmin Lu ◽  
Tong Li ◽  
Junran Sun ◽  
Jian Liang ◽  
...  
Keyword(s):  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Mitochondrial Fission ◽  
Critical Role ◽  
Photoreceptor Degeneration ◽  
Apoptotic Pathway ◽  
Neurosensory Retina

AbstractPhotoreceptor degeneration is a leading cause of visual impairment worldwide. Separation of neurosensory retina from the underlying retinal pigment epithelium is a prominent feature preceding photoreceptor degeneration in a variety of retinal diseases. Although ophthalmic surgeries have been well developed to restore retinal structures, post-op patients usually experience progressive photoreceptor degeneration and irreversible vision loss that is incurable at present. Previous studies point to a critical role of mitochondria-mediated apoptotic pathway in photoreceptor degeneration, but the upstream triggers remain largely unexplored. In this study, we show that after experimental RD induction, photoreceptors activate dynamin-related protein 1 (Drp1)-dependent mitochondrial fission pathway and subsequent apoptotic cascades. Mechanistically, endogenous ROS is necessary for Drp1 activation in vivo and exogenous ROS insult is sufficient to activate Drp1-dependent mitochondrial fission in cultured photoreceptors. Accordingly, inhibition of Drp1 activity effectively preserves mitochondrial integrity and rescues photoreceptors. Collectively, our data delineates a ROS-Drp1-mitochondria axis that promotes photoreceptor degeneration in retinal diseased models.

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