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International Ophthalmology Feb 2021To review the basic principles of ultra-widefield fundus autofluorescence (UWF-FAF) and discuss its clinical application for a variety of retinal and choroidal disorders. (Review)
Review
PURPOSE
To review the basic principles of ultra-widefield fundus autofluorescence (UWF-FAF) and discuss its clinical application for a variety of retinal and choroidal disorders.
METHODS
A systematic review of the PubMed database was performed using the search terms "ultra-widefield," "autofluorescence," "retinal disease" and "choroidal disease."
RESULTS
UWF-FAF imaging is a recently developed noninvasive retinal imaging modality with a wide imaging range that can locate peripheral fundus lesions that traditional fundus autofluorescence cannot. Multiple commercially available ultra-widefield imaging systems, including Heidelberg Spectralis and Optomap Ultra-Widefield systems, are available to the clinician. Imaging by UWF-FAF is more comprehensive; it can reflect the content and distribution of the predominant ocular fluorophore in retinal pigment epithelial cells and evaluate the metabolic status of RPE of various retinal and choroidal disorders.
CONCLUSION
UWF-FAF can detect abnormalities that traditional fundus autofluorescence cannot; therefore, it can be used to better elucidate disease pathogenesis, analyze genotype-phenotype correlations, diagnose and monitor disease.
Topics: Fluorescein Angiography; Fundus Oculi; Humans; Optical Imaging; Retina; Retinal Diseases
PubMed: 33040254
DOI: 10.1007/s10792-020-01609-9 -
American Journal of Ophthalmology Feb 2023To report the diagnosis and definitions, epidemiology, risk factors, and visual outcomes of fibrosis in neovascular age-related macular degeneration (nAMD). (Meta-Analysis)
Meta-Analysis Review
PURPOSE
To report the diagnosis and definitions, epidemiology, risk factors, and visual outcomes of fibrosis in neovascular age-related macular degeneration (nAMD).
DESIGN
Systematic review and meta-analysis.
METHODS
The review was performed using the Cochrane Handbook and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Observational studies and randomized controlled trials were included.
RESULTS
Identification of fibrosis is challenging. Optical coherence tomography angiography and polarization-sensitive optical coherence tomography represent novel options in multimodal imaging. The prevalence of fibrosis at baseline, 12, 24, and 60 months was 13%, 32%, 36%, and 56%, respectively. Approximately 60% of the fibrosis burden in nAMD at 5 years was present in the first year of treatment. Fibrosis development was highest in the first 12 months and slowed down over time. The risk factors of fibrosis included classic choroidal neovascularization (CNV), intra-retinal fluid, hemorrhage, hyperreflective material, CNV lesion size, and retinal thickness. Sub-retinal fluid and pigment epithelial detachment may be protective. Treatment-associated factors included disease activity and time to diagnosis. At baseline, the best corrected visual acuity in eyes with fibrosis was poorer than in eyes without fibrosis (-18.50 letters); this difference became larger at 12 months despite treatment (-26.86 letters).
CONCLUSIONS
There is a need to identify effective treatment strategies for fibrosis and to closely monitor at-risk patients. More studies involving multimodal imaging are required to clarify the definitions and grading criteria for fibrosis.
Topics: Humans; Angiogenesis Inhibitors; Retina; Choroidal Neovascularization; Fibrosis; Tomography, Optical Coherence; Macular Degeneration; Fluorescein Angiography; Intravitreal Injections; Wet Macular Degeneration
PubMed: 36162537
DOI: 10.1016/j.ajo.2022.09.008 -
Biomedicine & Pharmacotherapy =... Nov 2023Humans rely on vision as their most important sense. This is accomplished by photoreceptors (PRs) in the retina that detect light but cannot function without the support... (Review)
Review
Humans rely on vision as their most important sense. This is accomplished by photoreceptors (PRs) in the retina that detect light but cannot function without the support and maintenance of the retinal pigment epithelium (RPE). In subretinal hemorrhage (SRH), blood accumulates between the neurosensory retina and the RPE or between the RPE and the choroid. Blood breakdown products subsequently damage PRs and the RPE and lead to poor vision and blindness. Hence, there is a high need for options to preserve the retina and visual functions. We conducted a systematic review of the literature in accordance with the PRISMA guidelines to identify the cell death mechanisms in RPE and PRs after SRH to deepen our understanding of the pathways involved. After screening 736 publications published until November 8, 2022, we identified 19 records that assessed cell death in PRs and/or RPE in experimental models of SRH. Among the different cell death mechanisms, apoptosis was the most widely investigated mechanism (11 records), followed by ferroptosis (4), whereas necroptosis, pyroptosis, and lysosome-dependent cell death were only assessed in one study each. We discuss different therapeutic options that were assessed in these studies, including the removal of the hematoma/iron chelation, cytoprotection, anti-inflammatory agents, and antioxidants. Further systematic investigations will be necessary to determine the exact cell death mechanisms after SRH with respect to different blood breakdown components, cell types, and time courses. This will form the basis for the development of novel treatment options for SRH.
Topics: Humans; Retinal Pigment Epithelium; Retina; Cell Death; Photoreceptor Cells; Hemorrhage
PubMed: 37742603
DOI: 10.1016/j.biopha.2023.115572 -
Survey of Ophthalmology 2023Choroidal osteoma is a benign ossifying tumor within the choroid. Complications associated with choroidal osteoma, including disruption of retinal pigment epithelium,... (Review)
Review
Choroidal osteoma is a benign ossifying tumor within the choroid. Complications associated with choroidal osteoma, including disruption of retinal pigment epithelium, atrophy of photoreceptors, subretinal fluid, and choroidal neovascularization, present challenges for clinicians, and management remain controversial. We performed a comprehensive search in the PubMed, EMBASE, and Ovid databases for published studies and case reports relating to the management of choroidal osteoma. Since it was first described in 1978, various case reports of ocular complications associated with choroidal osteoma have been documented, and various therapies have yielded different outcomes. We systematically evaluate the literature published on this rare entity.
Topics: Humans; Choroid Neoplasms; Choroid; Osteoma; Choroidal Neovascularization; Retinal Pigment Epithelium; Fluorescein Angiography; Tomography, Optical Coherence
PubMed: 37321477
DOI: 10.1016/j.survophthal.2023.06.002 -
The British Journal of Ophthalmology Nov 2021Age-related macular disease (AMD) is a major cause of blindness and there is little treatment currently available by which the progress of the basic disorder can be... (Review)
Review
Age-related macular disease (AMD) is a major cause of blindness and there is little treatment currently available by which the progress of the basic disorder can be modulated. Histological and clinical studies show that the major tissues involved are the outer retina, retinal pigment epithelium, Bruch's membrane and choroid. Because of a wide variation of phenotype from one case to another, it has been suggested that accurate phenotyping would be necessary for assessment of the effectiveness of treatment that is tissue-directed. However, based on findings from the study of human donor material and animal models of disease and of cell culture, it is concluded that retinal pigment epithelial dysfunction plays a central role in the disease process in most, if not all, cases of early AMD. The metabolism of phagosomal material, particularly lipids, and energy generation are interdependent, and dysfunction of both appears to be important in the genesis of disease. Evidence exists to suggest that both can be modulated therapeutically. These metabolic functions are amenable to further investigation in both the normal state and in disease. Once fully characterised, it is likely that treatment could be directed towards a limited number of functions in single tissue, thus simplifying treatment strategies.
Topics: Aging; Bruch Membrane; Choroid; Humans; Lipid Metabolism; Macular Degeneration; Retina; Retinal Pigment Epithelium
PubMed: 32950958
DOI: 10.1136/bjophthalmol-2020-317447 -
Eye (London, England) Aug 2023The aim of this systematic literature review is twofold, (1) detail the impact of retinal biomarkers identifiable via optical coherence tomography (OCT) on disease... (Review)
Review
UNLABELLED
The aim of this systematic literature review is twofold, (1) detail the impact of retinal biomarkers identifiable via optical coherence tomography (OCT) on disease progression and response to treatment in neovascular age-related macular degeneration (nAMD) and (2) establish which biomarkers are currently identifiable by artificial intelligence (AI) models and the utilisation of this technology. Following the PRISMA guidelines, PubMed was searched for peer-reviewed publications dated between January 2016 and January 2022.
POPULATION
Patients diagnosed with nAMD with OCT imaging.
SETTINGS
Comparable settings to NHS hospitals.
STUDY DESIGNS
Randomised controlled trials, prospective/retrospective cohort studies and review articles. From 228 articles, 130 were full-text reviewed, 50 were removed for falling outside the scope of this review with 10 added from the author's inventory, resulting in the inclusion of 90 articles. From 9 biomarkers identified; intraretinal fluid (IRF), subretinal fluid, pigment epithelial detachment, subretinal hyperreflective material (SHRM), retinal pigmental epithelial (RPE) atrophy, drusen, outer retinal tabulation (ORT), hyperreflective foci (HF) and retinal thickness, 5 are considered pertinent to nAMD disease progression; IRF, SHRM, drusen, ORT and HF. A number of these biomarkers can be classified using current AI models. Significant retinal biomarkers pertinent to disease activity and progression in nAMD are identifiable via OCT; IRF being the most important in terms of the significant impact on visual outcome. Incorporating AI into ophthalmology practice is a promising advancement towards automated and reproducible analyses of OCT data with the ability to diagnose disease and predict future disease conversion.
SYSTEMATIC REVIEW REGISTRATION
This review has been registered with PROSPERO (registration ID: CRD42021233200).
Topics: Humans; Tomography, Optical Coherence; Artificial Intelligence; Retrospective Studies; Prospective Studies; Fluorescein Angiography; Biomarkers; Macular Degeneration; Disease Progression; Wet Macular Degeneration; Angiogenesis Inhibitors
PubMed: 36526863
DOI: 10.1038/s41433-022-02360-4 -
BMC Ophthalmology Nov 2023To evaluate the efficacy of anti-vascular endothelial growth factor (VEGF) in treatment of age-related macular degeneration (AMD) with retinal pigment epithelial... (Meta-Analysis)
Meta-Analysis
Comparative efficacy of aflibercept and ranibizumab in the treatment of age-related macular degeneration with retinal pigment epithelial detachment: a systematic review and network meta-analysis.
OBJECTIVES
To evaluate the efficacy of anti-vascular endothelial growth factor (VEGF) in treatment of age-related macular degeneration (AMD) with retinal pigment epithelial detachment (PED).
METHODS
Systematic review identifying studies comparing intravitreal ranibizumab (IVR), intravitreal aflibercept (IVA) and intravitreal conbercept (IVC) published before Mar 2022.
RESULTS
One randomized controlled trial and 6 observational studies were selected for meta-analysis (1,069 patients). The change of best corrected visual acuity (BCVA) in IVA 2.0 mg group was better than IVR 0.5 mg (average difference 0.07) and IVR 2.0 mg (average difference 0.10), the differences were statistically significant. The change of the height of PED in IVA 2.0 group was better than IVR 0.5 group (average difference 45.30), the difference was statistically significant. The proportion of patients without PED at last visit in IVA 2.0 group were better than those in IVR 2.0 group (hazard ratio 1.91), the difference was statistically significant. There was no significant difference compared with IVR 0.5 group (hazard ratio 1.45). IVA required fewer injections than IVR, with a mean difference of -1.58.
CONCLUSIONS
IVA appears to be superior to IVR in improvement of BCVA, height decrease of PED and regression of PED with less injections in nAMD with PED.
Topics: Humans; Ranibizumab; Angiogenesis Inhibitors; Retinal Detachment; Network Meta-Analysis; Vascular Endothelial Growth Factor A; Retinal Pigment Epithelium; Retrospective Studies; Receptors, Vascular Endothelial Growth Factor; Recombinant Fusion Proteins; Intravitreal Injections; Macular Degeneration
PubMed: 37990182
DOI: 10.1186/s12886-023-03214-7 -
Current Stem Cell Research & Therapy 2022The main cause of progressive vision impairment in retinal degenerative diseases is the dysfunction of photoreceptors and the underlying retinal pigment epithelial...
BACKGROUND
The main cause of progressive vision impairment in retinal degenerative diseases is the dysfunction of photoreceptors and the underlying retinal pigment epithelial cells. The inadequate regenerative capacity of the neural retina and lack of established therapeutic options demand the development of clinical-grade protocols to halt the degenerative process in the eye or replace the damaged cells by using stem cell-derived products. Recently, stem cell-based regenerative therapies have been at the forefront of clinical investigations for retinal dystrophies.
OBJECTIVE
This article will review different stem cell-based therapies currently employed for retinal degenerative diseases, recent clinical trials, and major challenges in the translation of these therapies from bench to bedside.
METHODOLOGY
A systematic literature review was conducted to identify potentially relevant articles published in MEDLINE/PubMed, Embase, ClinicalTrials.gov, Drugs@FDA, European Medicines Agency, and World Health Organization International Clinical Trials Registry Platform.
RESULTS
Transplantation of healthy cells to replace damaged cells in the outer retina is a clinically relevant concept because the inner retina that communicates with the visual areas of the brain remains functional even after the photoreceptors are completely lost. Various methods have been established for the differentiation of pluripotent stem cells into different retinal cell types that can be used for therapies. Factors released from transplanted somatic stem cells showed trophic support and photoreceptor rescue during the early stages of the disease. Several preclinical and phase I/II clinical studies using terminally differentiated photoreceptor/retinal pigment epithelial cells derived from pluripotent stem cells have shown proof of concept for visual restoration in Age-related Macular Degeneration (AMD), Stargardt disease, and Retinitis Pigmentosa (RP).
CONCLUSION
Cell replacement therapy has great potential for vision restoration. The results obtained from the initial clinical trials are encouraging and indicate its therapeutic benefits. The current status of the therapies suggests that there is a long way to go before these results can be applied to routine clinical practice. Input from the ongoing multicentre clinical trials will give a more refined idea for the future design of clinical-grade protocols to transplant GMP level HLA matched cells.
Topics: Humans; Pluripotent Stem Cells; Retina; Retinal Degeneration; Retinal Pigment Epithelium; Retinal Pigments; Stem Cell Transplantation
PubMed: 34348629
DOI: 10.2174/1574888X16666210804112104 -
Methods in Enzymology 2022The term "macular carotenoids" refers to the lutein, zeaxanthin, and meso-zeaxanthin that are highly concentrated at the center of the human retina. Intraretinal levels...
The term "macular carotenoids" refers to the lutein, zeaxanthin, and meso-zeaxanthin that are highly concentrated at the center of the human retina. Intraretinal levels of these carotenoids are inversely associated with the risk of age-related macular degeneration (AMD), and oral supplementation with these carotenoids can significantly reduce AMD risk. To make macular carotenoid analysis more accessible, we systematically review the current methods for extraction, detection, and imaging of macular carotenoids in both basic and clinical research. We first introduce carotenoid extraction methods from the retina, retinal pigment epithelium (RPE)/choroid, serum, and liver of the human and animal models, such as mice and Japanese quails, as well as from algae, bacteria, and chicken egg yolks and cultured cells. We then review macular carotenoid detection by spectroscopy and HPLC, while particularly introducing carotenoid separation via cyano columns, chiral columns, and C30 columns. In the end, we summarize the common methods used to image carotenoids in living human eyes: resonance Raman spectroscopy, autofluorescence attenuation spectroscopy, and reflection spectroscopy, and we then review the utility of confocal resonance Raman microscopy to image the macular carotenoids in tissue sections of human and mouse retinas.
Topics: Animals; Carotenoids; Chromatography, High Pressure Liquid; Humans; Lutein; Mice; Retina; Spectrum Analysis, Raman
PubMed: 36008007
DOI: 10.1016/bs.mie.2022.05.001 -
Advances in Therapy Mar 2022Inherited retinal dystrophies (IRDs) represent a genetically diverse group of progressive, visually debilitating diseases. Adult and paediatric patients with vision loss... (Review)
Review
INTRODUCTION
Inherited retinal dystrophies (IRDs) represent a genetically diverse group of progressive, visually debilitating diseases. Adult and paediatric patients with vision loss due to IRD caused by biallelic mutations in the 65-kDa retinal pigment epithelium (RPE65) gene are often clinically diagnosed as retinitis pigmentosa (RP), and Leber congenital amaurosis (LCA). This study aimed to understand the epidemiological landscape of RPE65 gene-mediated IRD through a systematic review of the literature, as the current evidence base for its epidemiology is very limited.
METHODS
Medline, Embase, and other databases were searched for articles on the epidemiology of RPE65 gene-mediated IRDs from inception until June 2021. Studies were included if they were original research articles reporting the epidemiology of RP and LCA and/or proportion of RPE65 gene mutations in these clinically diagnosed or molecularly confirmed IRDs patients.
RESULTS
A total of 100 studies with relevant data were included in this systematic review. The range for prevalence of LCA and RP in the literature was 1.20-2.37 and 11.09-26.43 per 100,000, respectively. The proportion of RPE65 mutations in clinically diagnosed patients with LCA was found to be between ~ 2-16% within the US and major European countries (France, Germany, Italy, Spain, and the UK). This range was also comparable to our findings in the Asian region for RPE65-LCA (1.26-16.67%). Similarly, for these European countries, RPE65-RP was estimated between 0.23 and 1.94%, and RPE65-IRD range was 1.2-14%. Further, in the Americas region, mutations in RPE65 were reported to cause 1-3% of RP and 0.8-3.7% of IRD cases. Lastly, the RPE65-IRD range was 4.81-8% in the Middle East region.
CONCLUSIONS
There are significant variations in reporting of RPE65 proportions within countries as well as regions. Generating robust epidemiological evidence on RPE65 gene-mediated IRDs would be fundamental to support rare disease awareness, timely therapeutic intervention, and public health decision-making.
Topics: Adult; Child; Humans; Leber Congenital Amaurosis; Mutation; Retinal Dystrophies; Retinal Pigment Epithelium; cis-trans-Isomerases
PubMed: 35098484
DOI: 10.1007/s12325-021-02036-7