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Bonnin S, Gocho K, Norberg N, Gofas E, Lejoyeux R, Chaumette C, Grieve K, Couturier A, Paques M. Spatially resolved imaging of human macular capillaries using adaptive optics-enhanced optical coherence tomography angiography. Sci Rep 2024; 14:15540. [PMID: 38969668 PMCID: PMC11226425 DOI: 10.1038/s41598-024-65534-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 06/19/2024] [Indexed: 07/07/2024] Open
Abstract
Documenting the organization of the retinal capillaries is of importance to understand the visual consequences of vascular diseases which may differentially affect the microvascular layers. Here we detailed the spatial organization of the macular capillaries in ten healthy human subjects using a prototypic adaptive optics-enhanced optical coherence tomography angiography (AO-OCTA) system. Within the central 6° × 6°, the radial peripapillary capillaries and the superficial, intermediate and deep vascular plexuses (SVP, IVP and DVP, respectively) were consistently resolved. In 8 out of the 10 eyes, the capillary segments composing the perifoveal arcade (PFA) were perfused only by the SVP, while drainage of the PFA showed more variability, comprising a case in which the PFA was drained by the DVP. Around the center, a distinct central avascular zone could be documented for each layer in 7 of the 10 cases; in three eyes, the IVP and SVP merged tangentially around the center. In all eyes, the foveal avascular zone was larger in the DVP than in the SVP and IVP. In one eye with incomplete separation of the inner foveal layers, there was continuity of both the SVP and the IVP; a central avascular zone was only present in the DVP. The diversity of perfusion and drainage patterns supported a connectivity scheme combining parallel and serial organizations, the latter being the most commonly observed in perifoveal vessels. Our results thus help to further characterize the diversity of organization patterns of the macular capillaries and to robustly analyze the IVP, which will help to characterize early stages of microvascular diseases.
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Affiliation(s)
- S Bonnin
- Paris Eye Imaging Group, Clinical Investigation Center Vision 1423, Quinze-Vingts Hospital, INSERM-DHOS, Sorbonne University, 28 Rue de Charenton, 75012, Paris, France
- Rothschild Foundation Hospital, 25-29 Rue Manin, 75019, Paris, France
| | - K Gocho
- Paris Eye Imaging Group, Clinical Investigation Center Vision 1423, Quinze-Vingts Hospital, INSERM-DHOS, Sorbonne University, 28 Rue de Charenton, 75012, Paris, France
| | - N Norberg
- Paris Eye Imaging Group, Clinical Investigation Center Vision 1423, Quinze-Vingts Hospital, INSERM-DHOS, Sorbonne University, 28 Rue de Charenton, 75012, Paris, France
- Institut de La Vision, 17 Rue Moreau, 75012, Paris, France
| | - E Gofas
- Paris Eye Imaging Group, Clinical Investigation Center Vision 1423, Quinze-Vingts Hospital, INSERM-DHOS, Sorbonne University, 28 Rue de Charenton, 75012, Paris, France
- Institut de La Vision, 17 Rue Moreau, 75012, Paris, France
| | - R Lejoyeux
- Rothschild Foundation Hospital, 25-29 Rue Manin, 75019, Paris, France
| | - C Chaumette
- Paris Eye Imaging Group, Clinical Investigation Center Vision 1423, Quinze-Vingts Hospital, INSERM-DHOS, Sorbonne University, 28 Rue de Charenton, 75012, Paris, France
| | - K Grieve
- Paris Eye Imaging Group, Clinical Investigation Center Vision 1423, Quinze-Vingts Hospital, INSERM-DHOS, Sorbonne University, 28 Rue de Charenton, 75012, Paris, France
- Institut de La Vision, 17 Rue Moreau, 75012, Paris, France
| | - A Couturier
- Paris Eye Imaging Group, Clinical Investigation Center Vision 1423, Quinze-Vingts Hospital, INSERM-DHOS, Sorbonne University, 28 Rue de Charenton, 75012, Paris, France
- Université Paris Cité, Ophthalmology Department, AP-HP, Lariboisière Hospital-Assistance Publique-Hôpitaux de Paris, Paris, France
| | - M Paques
- Paris Eye Imaging Group, Clinical Investigation Center Vision 1423, Quinze-Vingts Hospital, INSERM-DHOS, Sorbonne University, 28 Rue de Charenton, 75012, Paris, France.
- Institut de La Vision, 17 Rue Moreau, 75012, Paris, France.
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Nouri H, Abtahi SH, Mazloumi M, Samadikhadem S, Arevalo JF, Ahmadieh H. Optical coherence tomography angiography in diabetic retinopathy: A major review. Surv Ophthalmol 2024; 69:558-574. [PMID: 38521424 DOI: 10.1016/j.survophthal.2024.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 02/29/2024] [Accepted: 03/11/2024] [Indexed: 03/25/2024]
Abstract
Diabetic retinopathy (DR) is characterized by retinal vasculopathy and is a leading cause of visual impairment. Optical coherence tomography angiography (OCTA) is an innovative imaging technology that can detect various pathologies and quantifiable changes in retinal microvasculature. We briefly describe its functional principles and advantages over fluorescein angiography and perform a comprehensive review on its clinical applications in the screening or management of people with prediabetes, diabetes without clinical retinopathy (NDR), nonproliferative DR (NPDR), proliferative DR (PDR), and diabetic macular edema (DME). OCTA reveals early microvascular alterations in prediabetic and NDR eyes, which may coexist with sub-clinical neuroretinal dysfunction. Its applications in NPDR include measuring ischemia, detecting retinal neovascularization, and timing of early treatment through predicting the risk of retinopathy worsening or development of DME. In PDR, OCTA helps characterize the flow within neovascular complexes and evaluate their progression or regression in response to treatment. In eyes with DME, OCTA perfusion parameters may be of predictive value regarding the visual and anatomical gains associated with treatment. We further discussed the limitations of OCTA and the benefits of its incorporation into an updated DR severity scale.
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Affiliation(s)
- Hosein Nouri
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran; School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Seyed-Hossein Abtahi
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Ophthalmology, Labbafinejad Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Mehdi Mazloumi
- Eye Research Center, Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Sanam Samadikhadem
- Department of Ophthalmology, Imam Hossein Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - J Fernando Arevalo
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Hamid Ahmadieh
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Fayed AE, Menten MJ, Kreitner L, Paetzold JC, Rueckert D, Bassily SM, Fikry RR, Hagag AM, Sivaprasad S. Retinal vasculature of different diameters and plexuses exhibit distinct vulnerability in varying severity of diabetic retinopathy. Eye (Lond) 2024; 38:1762-1769. [PMID: 38514853 PMCID: PMC11156674 DOI: 10.1038/s41433-024-03021-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 02/08/2024] [Accepted: 03/06/2024] [Indexed: 03/23/2024] Open
Abstract
OBJECTIVES To study the changes in vessel densities (VD) stratified by vessel diameter in the retinal superficial and deep vascular complexes (SVC/DVC) using optical coherence tomography angiography (OCTA) images obtained from people with diabetes and age-matched healthy controls. METHODS We quantified the VD based on vessel diameter categorized as <10, 10-20 and >20 μm in the SVC/DVC obtained on 3 × 3 mm2 OCTA scans using a deep learning-based segmentation and vascular graph extraction tool in people with diabetes and age-matched healthy controls. RESULTS OCTA images obtained from 854 eyes of 854 subjects were divided into 5 groups: healthy controls (n = 555); people with diabetes with no diabetic retinopathy (DR, n = 90), mild and moderate non-proliferative DR (NPDR) (n = 96), severe NPDR (n = 42) and proliferative DR (PDR) (n = 71). Both SVC and DVC showed significant decrease in VD with increasing DR severity (p < 0.001). The largest difference was observed in the <10 μm vessels of the SVC between healthy controls and no DR (13.9% lower in no DR, p < 0.001). Progressive decrease in <10 μm vessels of the SVC and DVC was seen with increasing DR severity (p < 0.001). However, 10-20 μm vessels only showed decline in the DVC, but not the SVC (p < 0.001) and there was no change observed in the >20 μm vessels in either plexus. CONCLUSIONS Our findings suggest that OCTA is able to demonstrate a distinct vulnerability of the smallest retinal vessels in both plexuses that worsens with increasing severity of DR.
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Affiliation(s)
- Alaa E Fayed
- Department of Ophthalmology, Kasr Al-Ainy School of Medicine, Cairo University, Giza, Egypt.
- Watany Eye Hospital, Cairo, Egypt.
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
| | - Martin J Menten
- Lab for AI in Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- BioMedIA, Imperial College London, London, UK
| | - Linus Kreitner
- Lab for AI in Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Johannes C Paetzold
- Lab for AI in Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- BioMedIA, Imperial College London, London, UK
| | - Daniel Rueckert
- Lab for AI in Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- BioMedIA, Imperial College London, London, UK
| | | | - Ramy R Fikry
- Department of Ophthalmology, Kasr Al-Ainy School of Medicine, Cairo University, Giza, Egypt
- Watany Eye Hospital, Cairo, Egypt
| | - Ahmed M Hagag
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, London, UK
- Boehringer Ingelheim Limited, London, UK
| | - Sobha Sivaprasad
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, London, UK
- University College London, London, UK
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Hein M, Qambari H, An D, Balaratnasingam C. Current understanding of subclinical diabetic retinopathy informed by histology and high-resolution in vivo imaging. Clin Exp Ophthalmol 2024; 52:464-484. [PMID: 38363022 DOI: 10.1111/ceo.14363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/21/2024] [Accepted: 01/26/2024] [Indexed: 02/17/2024]
Abstract
The escalating incidence of diabetes mellitus has amplified the global impact of diabetic retinopathy. There are known structural and functional changes in the diabetic retina that precede the fundus photography abnormalities which currently are used to diagnose clinical diabetic retinopathy. Understanding these subclinical alterations is important for effective disease management. Histology and high-resolution clinical imaging reveal that the entire neurovascular unit, comprised of retinal vasculature, neurons and glial cells, is affected in subclinical disease. Early functional manifestations are seen in the form of blood flow and electroretinography disturbances. Structurally, there are alterations in the cellular components of vasculature, glia and the neuronal network. On clinical imaging, changes to vessel density and thickness of neuronal layers are observed. How these subclinical disturbances interact and ultimately manifest as clinical disease remains elusive. However, this knowledge reveals potential early therapeutic targets and the need for imaging modalities that can detect subclinical changes in a clinical setting.
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Affiliation(s)
- Martin Hein
- Physiology and Pharmacology Group, Lions Eye Institute, Perth, Western Australia, Australia
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Western Australia, Australia
| | - Hassanain Qambari
- Physiology and Pharmacology Group, Lions Eye Institute, Perth, Western Australia, Australia
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Western Australia, Australia
| | - Dong An
- Physiology and Pharmacology Group, Lions Eye Institute, Perth, Western Australia, Australia
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Western Australia, Australia
| | - Chandrakumar Balaratnasingam
- Physiology and Pharmacology Group, Lions Eye Institute, Perth, Western Australia, Australia
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Western Australia, Australia
- Department of Ophthalmology, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
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5
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Hernandez RJ, Madhusudhan S, Zheng Y, El-Bouri WK. Linking Vascular Structure and Function: Image-Based Virtual Populations of the Retina. Invest Ophthalmol Vis Sci 2024; 65:40. [PMID: 38683566 PMCID: PMC11059806 DOI: 10.1167/iovs.65.4.40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 04/02/2024] [Indexed: 05/01/2024] Open
Abstract
Purpose This study explored the relationship among microvascular parameters as delineated by optical coherence tomography angiography (OCTA) and retinal perfusion. Here, we introduce a versatile framework to examine the interplay between the retinal vascular structure and function by generating virtual vasculatures from central retinal vessels to macular capillaries. Also, we have developed a hemodynamics model that evaluates the associations between vascular morphology and retinal perfusion. Methods The generation of the vasculature is based on the distribution of four clinical parameters pertaining to the dimension and blood pressure of the central retinal vessels, constructive constrained optimization, and Voronoi diagrams. Arterial and venous trees are generated in the temporal retina and connected through three layers of capillaries at different depths in the macula. The correlations between total retinal blood flow and macular flow fraction and vascular morphology are derived as Spearman rank coefficients, and uncertainty from input parameters is quantified. Results A virtual cohort of 200 healthy vasculatures was generated. Means and standard deviations for retinal blood flow and macular flow fraction were 20.80 ± 7.86 µL/min and 15.04% ± 5.42%, respectively. Retinal blood flow was correlated with vessel area density, vessel diameter index, fractal dimension, and vessel caliber index. The macular flow fraction was not correlated with any morphological metrics. Conclusions The proposed framework is able to reproduce vascular networks in the macula that are morphologically and functionally similar to real vasculature. The framework provides quantitative insights into how macular perfusion can be affected by changes in vascular morphology delineated on OCTA.
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Affiliation(s)
- Rémi J. Hernandez
- Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool Heart and Chest Hospital, Liverpool, United Kingdom
- Department of Cardiovascular and Metabolic Medicine, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Savita Madhusudhan
- St Paul's Eye Unit, Liverpool University Hospitals NHS Foundation Trust, Liverpool, United Kingdom
- Department of Eye and Vision Sciences, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Yalin Zheng
- St Paul's Eye Unit, Liverpool University Hospitals NHS Foundation Trust, Liverpool, United Kingdom
- Department of Eye and Vision Sciences, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Wahbi K. El-Bouri
- Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool Heart and Chest Hospital, Liverpool, United Kingdom
- Department of Cardiovascular and Metabolic Medicine, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
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Ramtohul P, Au A, Kunkler AL, Bacci T, Dolz-Marco R, Gallego-Pinazo R, Yannuzzi N, Sarraf D, Freund KB. CENTRAL BOUQUET HEMORRHAGE: Clinical and Multimodal Imaging Features. Retina 2024; 44:551-557. [PMID: 38109663 DOI: 10.1097/iae.0000000000004025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
PURPOSE To describe the clinical characteristics, multimodal imaging features, and anatomic basis of a distinctive pattern of deep retinal hemorrhages located in the central fovea, a presentation referred to as "central bouquet hemorrhage." METHODS Retrospective, observational, multicenter case series of eyes with central bouquet hemorrhage. Multimodal imaging features were reviewed and analyzed. RESULTS Ten eyes from 10 patients (4 women and 6 men), with a mean age of 55.6 ± 21.7 years (range 25-84 years) were included. Underlying etiologies were neovascular age-related macular degeneration (40%), lacquer cracks in pathological myopia (30%), macular telangiectasia Type 2 (10%), proliferative diabetic retinopathy (10%), and ocular trauma associated with angioid streaks (10%). On ophthalmoscopy, all eyes with central bouquet hemorrhage displayed a deep retinal hemorrhage with round margins in the central fovea and associated with petaloid hemorrhages radiating in the surrounding Henle fiber layer. Cross-sectional optical coherence tomography showed a well-delineated round hyperreflective lesion involving the central foveal Henle fiber layer/outer nuclear layer in all cases. Accompanying hyperreflective hemorrhages tracking along the obliquely oriented Henle fiber layer were present in all eyes. Resolution occurred in all patients, either spontaneously (30%) or after treatment with intravitreal anti-vascular endothelial growth factor injections (70%), and was associated with partial visual acuity improvement (from 20/113 to 20/36). CONCLUSION "Central bouquet hemorrhage" is a novel descriptive term describing a characteristic round pattern of intraretinal blood in the fovea associated with Henle fiber layer hemorrhage and encountered in a spectrum of macular disease.
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Affiliation(s)
- Prithvi Ramtohul
- Vitreous Retina Macula Consultants of New York, New York, New York
| | - Adrian Au
- Retinal Disorders and Ophthalmic Genetics Division, Stein Eye Institute, University of California Los Angeles, Los Angeles, California
| | - Anne L Kunkler
- Department of Ophthalmology, Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, Florida
| | - Tommaso Bacci
- Ophthalmology Unit, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena University Hospital, Siena, Italy
| | | | | | - Nicolas Yannuzzi
- Department of Ophthalmology, Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, Florida
| | - David Sarraf
- Retinal Disorders and Ophthalmic Genetics Division, Stein Eye Institute, University of California Los Angeles, Los Angeles, California
| | - K Bailey Freund
- Vitreous Retina Macula Consultants of New York, New York, New York
- Department of Ophthalmology, NYU Grossman School of Medicine, New York, New York
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7
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Steffen S, Buscher L, Leclaire MD, Nelis P, Alnawaiseh M, Schneider G, Conrad R, Eter N, Brücher VC. Originalbeiträge (Originals). Altered microvascular density in patients with anorexia nervosa – an optical coherence tomography angiography (OCTA) pilot study. ZEITSCHRIFT FUR PSYCHOSOMATISCHE MEDIZIN UND PSYCHOTHERAPIE 2024; 70:24-34. [PMID: 38598705 DOI: 10.13109/zptm.2024.70.1.24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
OBJECTIVES To investigate macular and peripapillary vascular density (VD) in patients with anorexia nervosa (AN) compared to healthy controls. Methods:Whole face scans of the superficial and deep macular layers and whole face and peripapillary scans of the radial peripapillary capillaries (RPC) were obtained using optical coherence tomography angiography (OCTA, AngioVueR, Optovue) in ten patients with AN and ten age-matched controls.The primary objective was to determine whether there was a difference between the vessel density (VD) in the above areas in AN and controls. P-values ≤ 0.0125 were considered statistically significant. Results: VD in the superficialmacular en-face OCTA image was significantly lower in the study group compared to the control group. Neither the deepmacula nor the radial peripapillary capillary (RPC) in the whole-face image nor the RPC-peripapillary imaging appeared to be significantly different. Conclusion: Patients with AN showed reduced VD in the superficialmacular layers compared to healthy controls, which can be discussed as a consequence of the malnutrition. OCTA could be a useful non- invasive tool to detect reduced peripheral blood supply to show vascular changes that occur before ocular symptoms.
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8
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Maung Ye SS, Phng LK. A cell-and-plasma numerical model reveals hemodynamic stress and flow adaptation in zebrafish microvessels after morphological alteration. PLoS Comput Biol 2023; 19:e1011665. [PMID: 38048371 PMCID: PMC10721208 DOI: 10.1371/journal.pcbi.1011665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 12/14/2023] [Accepted: 11/06/2023] [Indexed: 12/06/2023] Open
Abstract
The development of a functional cardiovascular system ensures a sustainable oxygen, nutrient and hormone delivery system for successful embryonic development and homeostasis in adulthood. While early vessels are formed by biochemical signaling and genetic programming, the onset of blood flow provides mechanical cues that participate in vascular remodeling of the embryonic vascular system. The zebrafish is a prolific animal model for studying the quantitative relationship between blood flow and vascular morphogenesis due to a combination of favorable factors including blood flow visualization in optically transparent larvae. In this study, we have developed a cell-and-plasma blood transport model using computational fluid dynamics (CFD) to understand how red blood cell (RBC) partitioning affect lumen wall shear stress (WSS) and blood pressure in zebrafish trunk blood vascular networks with altered rheology and morphology. By performing live imaging of embryos with reduced hematocrit, we discovered that cardiac output and caudal artery flow rates were maintained. These adaptation trends were recapitulated in our CFD models, which showed reduction in network WSS via viscosity reduction in the caudal artery/vein and via pressure gradient weakening in the intersegmental vessels (ISVs). Embryos with experimentally reduced lumen diameter showed reduced cardiac output and caudal artery flow rate. Factoring in this trend into our CFD models, simulations highlighted that lumen diameter reduction increased vessel WSS but this increase was mitigated by flow reduction due to the adaptive network pressure gradient weakening. Additionally, hypothetical network CFD models with different vessel lumen diameter distribution characteristics indicated the significance of axial variation in lumen diameter and cross-sectional shape for establishing physiological WSS gradients along ISVs. In summary, our work demonstrates how both experiment-driven and hypothetical CFD modeling can be employed for the study of blood flow physiology during vascular remodeling.
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Affiliation(s)
- Swe Soe Maung Ye
- Laboratory for Vascular Morphogenesis, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, Japan
| | - Li-Kun Phng
- Laboratory for Vascular Morphogenesis, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, Japan
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Bousquet E, Santina A, Abraham N, Daily MJ, Sarraf D. Detection of Paracentral Acute Middle Maculopathy Can Prevent Blindness and Death. Retina 2023; 43:1827-1832. [PMID: 37748460 DOI: 10.1097/iae.0000000000003939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Affiliation(s)
- Elodie Bousquet
- Retinal Disorders and Ophthalmic Genetics Division, Stein Eye Institute, University of California Los Angeles, Los Angeles, California
| | - Ahmad Santina
- Retinal Disorders and Ophthalmic Genetics Division, Stein Eye Institute, University of California Los Angeles, Los Angeles, California
| | - Neda Abraham
- Retinal Disorders and Ophthalmic Genetics Division, Stein Eye Institute, University of California Los Angeles, Los Angeles, California
| | | | - David Sarraf
- Retinal Disorders and Ophthalmic Genetics Division, Stein Eye Institute, University of California Los Angeles, Los Angeles, California
- Greater Los Angeles Virginia Healthcare Center, Los Angeles, California
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10
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Neriyanuri S, Bedggood P, Symons RCA, Metha A. Mapping the human parafoveal vascular network to understand flow variability in capillaries. PLoS One 2023; 18:e0292962. [PMID: 37831712 PMCID: PMC10575526 DOI: 10.1371/journal.pone.0292962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 10/03/2023] [Indexed: 10/15/2023] Open
Abstract
Capillary flow is known to be non-homogenous between vessels and variable over time, for reasons that are poorly understood. The local properties of individual vessels have been shown to have limited explanatory power in this regard. This exploratory study investigates the association of network-level properties such as vessel depth, branch order, and distance from the feeding arteriole with capillary flow. Detailed network connectivity analysis was undertaken in 3 healthy young subjects using flood-illuminated adaptive optics retinal imaging, with axial depth of vessels determined via optical coherence tomography angiography. Forty-one out of 70 vessels studied were of terminal capillary type, i.e. fed from an arterial junction and drained by a venous junction. Approximately half of vessel junctions were amenable to fitting with a model of relative branch diameters, with only a few adhering to Murray's Law. A key parameter of the model (the junction exponent) was found to be inversely related to the average velocity (r = -0.59, p = 0.015) and trough velocity (r = -0.67, p = 0.004) in downstream vessels. Aspects of cellular flow, such as the minimum velocity, were also moderately correlated (r = 0.46, p = 0.009) with distance to the upstream feeding arteriole. Overall, this study shows that capillary network topology contributes significantly to the flow variability in retinal capillaries in human eyes. Understanding the heterogeneity in capillary flow is an important first step before pathological flow states can be properly understood. These results show that flow within capillary vessels is not affected by vessel depths but significantly influenced by the upstream feeder distance as well as the downstream vessel junction exponents, but there remains much to be uncovered regarding healthy capillary flow.
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Affiliation(s)
- Srividya Neriyanuri
- Department of Optometry and Vision Sciences, The University of Melbourne, Victoria, Australia
| | - Phillip Bedggood
- Department of Optometry and Vision Sciences, The University of Melbourne, Victoria, Australia
| | - R. C. Andrew Symons
- Department of Optometry and Vision Sciences, The University of Melbourne, Victoria, Australia
- Department of Surgery, The University of Melbourne, Victoria, Australia
- Centre for Eye Research Australia, Victoria, Australia
- Department of Surgery, Alfred Hospital, Monash University, Victoria, Australia
| | - Andrew Metha
- Department of Optometry and Vision Sciences, The University of Melbourne, Victoria, Australia
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11
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McAllister IL, Smithies LA, Chen FK, Mackey DA, Sanfilippo PG. Benefits of a Laser Chorioretinal Anastomosis Plus Ranibizumab vs Ranibizumab Alone for Central Retinal Vein Occlusion: 4-Year Results. Am J Ophthalmol 2023; 252:101-110. [PMID: 37030494 DOI: 10.1016/j.ajo.2023.03.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 03/25/2023] [Accepted: 03/27/2023] [Indexed: 04/10/2023]
Abstract
PURPOSE To evaluate what clinical gains can be achieved over conventional treatment with ranibizumab alone for central retinal vein occlusion (CRVO) when causal pathology is additionally addressed successfully with a laser-induced chorio-retinal anastomosis (L-CRA). DESIGN Two-year extension of prospective, randomized controlled clinical trial. METHODS A total of 58 patients with macular edema secondary to CRVO were randomized 1:1 to receive either an L-CRA (n = 29) or sham procedure (n = 29) at baseline and then monthly intravitreal ranibizumab 0.5 mg. Outcomes (best corrected visual acuity [BCVA], central subfield thickness [CST], injection requirements) were monitored in the monthly pro re nata (PRN) ranibizumab phase from months 7 to 48. RESULTS Injection requirements for patients with a functioning L-CRA (24 of 29) during the monthly PRN period from 7 to 24 months were a mean (95% CI) of 2.18 (1.57, 2.78) injections compared to 7.07 (6.08, 8.06) (P < .0001) for control (ranibizumab alone). These decreased further over the next 2 years to 0.29 (0.14, 0.61) compared to 2.20 (1.68, 2.88) (P < .001) for the third year and 0.25 (0.11, 0.56) and 1.84 (1.34, 2.54) for the fourth year (P < .001). Mean BCVA was statistically different at all follow-up time points from month 7 through month 48 for the group with the functioning L-CRA compared to the control monotherapy group. This improved to 14.06 letters at month 48 (P = .009). There was no difference in CST between any of the groups over the 48 months of follow-up. CONCLUSION For CRVO patients, addressing causal pathology in addition to conventional therapy improves BCVA and reduces injection requirements.
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Affiliation(s)
- Ian L McAllister
- From the Centre for Ophthalmology and Visual Science (I.L.M., L.A.S., F.K.C., D.A.M., P.G.S.), Lions Eye Institute, University of Western Australia, Perth, Australia.
| | - Lynne A Smithies
- From the Centre for Ophthalmology and Visual Science (I.L.M., L.A.S., F.K.C., D.A.M., P.G.S.), Lions Eye Institute, University of Western Australia, Perth, Australia
| | - Fred K Chen
- From the Centre for Ophthalmology and Visual Science (I.L.M., L.A.S., F.K.C., D.A.M., P.G.S.), Lions Eye Institute, University of Western Australia, Perth, Australia
| | - David A Mackey
- From the Centre for Ophthalmology and Visual Science (I.L.M., L.A.S., F.K.C., D.A.M., P.G.S.), Lions Eye Institute, University of Western Australia, Perth, Australia
| | - Paul G Sanfilippo
- From the Centre for Ophthalmology and Visual Science (I.L.M., L.A.S., F.K.C., D.A.M., P.G.S.), Lions Eye Institute, University of Western Australia, Perth, Australia; Centre for Eye Research Australia (P.G.S.), University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
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Shiga Y, Nishida T, Jeoung JW, Di Polo A, Fortune B. Optical Coherence Tomography and Optical Coherence Tomography Angiography: Essential Tools for Detecting Glaucoma and Disease Progression. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1217125. [PMID: 37982032 PMCID: PMC10655832 DOI: 10.3389/fopht.2023.1217125] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/03/2023] [Indexed: 11/21/2023]
Abstract
Early diagnosis and detection of disease progression are critical to successful therapeutic intervention in glaucoma, the leading cause of irreversible blindness worldwide. Optical coherence tomography (OCT) is a non-invasive imaging technique that allows objective quantification in vivo of key glaucomatous structural changes in the retina and the optic nerve head (ONH). Advances in OCT technology have increased the scan speed and enhanced image quality, contributing to early glaucoma diagnosis and monitoring, as well as the visualization of critically important structures deep within the ONH, such as the lamina cribrosa. OCT angiography (OCTA) is a dye-free technique for noninvasively assessing ocular microvasculature, including capillaries within each plexus serving the macula, peripapillary retina and ONH regions, as well as the deeper vessels of the choroid. This layer-specific assessment of the microvasculature has provided evidence that retinal and choroidal vascular impairments can occur during early stages of glaucoma, suggesting that OCTA-derived measurements could be used as biomarkers for enhancing detection of glaucoma and its progression, as well as to reveal novel insights about pathophysiology. Moreover, these innovations have demonstrated that damage to the macula, a critical region for the vision-related quality of life, can be observed in the early stages of glaucomatous eyes, leading to a paradigm shift in glaucoma monitoring. Other advances in software and hardware, such as artificial intelligence-based algorithms, adaptive optics, and visible-light OCT, may further benefit clinical management of glaucoma in the future. This article reviews the utility of OCT and OCTA for glaucoma diagnosis and disease progression detection, emphasizes the importance of detecting macula damage in glaucoma, and highlights the future perspective of OCT and OCTA. We conclude that the OCT and OCTA are essential glaucoma detection and monitoring tools, leading to clinical and economic benefits for patients and society.
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Affiliation(s)
- Yukihiro Shiga
- Neuroscience Division, Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec H2X 0A9, Canada
- Department of Neuroscience, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Takashi Nishida
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, La Jolla, California 92093, USA
| | - Jin Wook Jeoung
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Adriana Di Polo
- Neuroscience Division, Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec H2X 0A9, Canada
- Department of Neuroscience, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Brad Fortune
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, 1225 NE Second Avenue, Portland, Oregon 97232, USA
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13
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Drakopoulos M, Zhang DL, Cheng BT, Sadiq SA, Nadel A, Marchese A, Eskandari M, Mirza RG. Swept-source optical coherence tomography angiography metrics of retinal ischaemic perivascular lesions in patients being evaluated for carotid artery stenosis and controls. BMJ Open Ophthalmol 2023; 8:e001226. [PMID: 37493668 PMCID: PMC10357701 DOI: 10.1136/bmjophth-2022-001226] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 06/11/2023] [Indexed: 07/27/2023] Open
Abstract
BACKGROUND/AIMS Retinal microvascular ischaemia may produce localised middle retinal disruption with corresponding scotoma, a phenomenon termed paracentral acute middle maculopathy (PAMM). Small chronic middle retinal atrophic lesions termed retinal ischaemic perivascular lesions (RIPLs) appear qualitatively similar to PAMM lesions and have recently been hypothesised to result specifically from PAMM. However, no studies have quantitatively demonstrated an ischaemic origin of RIPLs. We quantitatively investigated the pathophysiology of RIPLs and their relationship with PAMM with swept-source optical coherence tomography angiography (SS-OCTA). METHODS A total of 14 controls and 25 patients being evaluated for carotid artery stenosis (CAS) were enrolled. SS-OCTA imaging of each eye was taken. Projection-resolved en face 6 mm × 6 mm superficial capillary plexus (SCP) and deep capillary plexus (DCP) images were quantitatively analysed with two algorithms for changes in vessel linear density (VLD) and vessel tortuosity (VT) at RIPLs relative to both the immediately surrounding macula and the entire macula, as well as between eyes with RIPLs and eyes without RIPLs. RESULTS All controls and 22 of 25 CAS patients were included in the analysis. RIPLs demonstrated a localised decrease in DCP VLD in CAS patients and controls. RIPLs tended to show a localised decrease in SCP VLD in CAS patients but a localised increase in controls. No changes in VT were found. Eyes with RIPLs had VLD and VT similar to their RIPL-free fellow eyes. CONCLUSION RIPLs are associated with quantifiable local, but not global, ischaemia, supporting the idea of shared pathophysiology with classic PAMM lesions along a continuum of ischaemia severity.
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Affiliation(s)
- Michael Drakopoulos
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - David L Zhang
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Brian T Cheng
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Saena Arifeen Sadiq
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Arnold Nadel
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Alessandro Marchese
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Mark Eskandari
- Department of Surgery, Division of Vascular Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Rukhsana G Mirza
- Department of Ophthalmology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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14
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Yu DY, Mehnert A, Balaratnasingam C, Yu PK, Hein M, An D, Cringle SJ. An assessment of microvascular hemodynamics in human macula. Sci Rep 2023; 13:7550. [PMID: 37160984 PMCID: PMC10169832 DOI: 10.1038/s41598-023-33490-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 04/13/2023] [Indexed: 05/11/2023] Open
Abstract
An adequate blood supply to meet the energy demands is essential for any tissue, particularly for high energy demand tissues such as the retina. A critical question is: How is the dynamic match between neuronal demands and blood supply achieved? We present a quantitative assessment of temporal and spatial variations in perfusion in the macular capillary network in 10 healthy human subjects using a non-invasive and label-free imaging technique. The assessment is based on the calculation of the coefficient of variation (CoV) of the perfusion signal from arterioles, venules and capillaries from a sequence of optical coherence tomography angiography images centred on the fovea. Significant heterogeneity of the spatial and temporal variation was found within arterioles, venules and capillary networks. The CoV values of the capillaries and smallest vessels were significantly higher than that in the larger vessels. Our results demonstrate the presence of significant heterogeneity of spatial and temporal variation within each element of the macular microvasculature, particularly in the capillaries and finer vessels. Our findings suggest that the dynamic match between neuronal demands and blood supply is achieved by frequent alteration of local blood flow evidenced by capillary perfusion variations both spatially and temporally in the macular region.
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Affiliation(s)
- Dao-Yi Yu
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Australia.
- Lions Eye Institute, 2 Verdun St, Nedlands, Perth, WA, 6009, Australia.
| | - Andrew Mehnert
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Australia
- Lions Eye Institute, 2 Verdun St, Nedlands, Perth, WA, 6009, Australia
| | - Chandrakumar Balaratnasingam
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Australia
- Lions Eye Institute, 2 Verdun St, Nedlands, Perth, WA, 6009, Australia
- Sir Charles Gairdner Hospital, Perth, Australia
| | - Paula K Yu
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Australia
- Lions Eye Institute, 2 Verdun St, Nedlands, Perth, WA, 6009, Australia
| | - Martin Hein
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Australia
- Lions Eye Institute, 2 Verdun St, Nedlands, Perth, WA, 6009, Australia
| | - Dong An
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Australia
- Lions Eye Institute, 2 Verdun St, Nedlands, Perth, WA, 6009, Australia
| | - Stephen J Cringle
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Australia
- Lions Eye Institute, 2 Verdun St, Nedlands, Perth, WA, 6009, Australia
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15
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Ong JX, Bou Ghanem GO, Nesper PL, Moonjely J, Fawzi AA. Optical Coherence Tomography Angiography of Volumetric Arteriovenous Relationships in the Healthy Macula and Their Derangement in Disease. Invest Ophthalmol Vis Sci 2023; 64:6. [PMID: 37133834 PMCID: PMC10166119 DOI: 10.1167/iovs.64.5.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 04/09/2023] [Indexed: 05/04/2023] Open
Abstract
Purpose To characterize relative arteriovenous connectivity of the healthy macula imaged by optical coherence tomography angiography (OCTA) using a new volumetric tool. Methods OCTA volumes were obtained for 20 healthy controls (20 eyes). Two graders identified superficial arterioles and venules. We implemented a custom watershed algorithm to identify capillaries most closely connected to arterioles and venules by using the large vessels as seeds to flood the vascular network. We calculated ratios of arteriolar- to venular-connected capillaries (A/V ratios) and adjusted flow indices (AFIs) for superficial capillary plexuses (SCPs), middle capillary plexuses (MCPs), and deep capillary plexuses (DCPs). We also analyzed two eyes with proliferative diabetic retinopathy (PDR) and one eye with macular telangiectasia (MacTel) to evaluate the utility of this method in visualizing pathological vascular connectivity. Results In healthy eyes, the MCP showed a greater proportion of arteriolar-connected vessels than the SCP and DCP (all P < 0.001). In the SCP, the arteriolar-connected AFI exceeded the venular-connected AFI, but this pattern reversed in the MCP and DCP, with higher venular-connected AFI (all P < 0.001). In PDR eyes, preretinal neovascularization originated from venules, whereas intraretinal microvascular abnormalities were heterogeneous, with some originating from venules and others representing dilated MCP capillary loops. In MacTel, diving SCP venules formed the epicenter of the outer retinal anomalous vascular network. Conclusions Healthy eyes showed a higher MCP A/V ratio but relatively slower arteriolar vs. venular flow velocity in the MCP and DCP, which may explain deep retinal vulnerability to ischemia. In eyes with complex vascular pathology, our connectivity findings were consistent with histopathologic studies.
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Affiliation(s)
- Janice X Ong
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
| | - Ghazi O Bou Ghanem
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
| | - Peter L Nesper
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
| | - Jessica Moonjely
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
| | - Amani A Fawzi
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
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16
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Stoyukhina AS. [Multimodal diagnostics of retinal cavernous hemangioma]. Vestn Oftalmol 2023; 139:52-58. [PMID: 37638572 DOI: 10.17116/oftalma202313904152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/29/2023]
Abstract
Cavernous hemangioma of the retina - a rarely occurring hamartoma that is predominantly found in the young age; it can be accompanied by cavernous hemangiomas of the skin and central nervous system. In Russian scientific literature this disease has not been described in sufficient detail. The article presents two clinical cases of incidentally diagnosed cavernous hemangioma of the retina. Multimodal diagnostics approach was used to confirm histological findings described in literature, which are characteristic of retinal cavernous hemangioma.
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Affiliation(s)
- A S Stoyukhina
- Krasnov Research Institute of Eye Diseases, Moscow, Russia
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17
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Fletcher EL, Dixon MA, Mills SA, Jobling AI. Anomalies in neurovascular coupling during early diabetes: A review. Clin Exp Ophthalmol 2023; 51:81-91. [PMID: 36349522 PMCID: PMC10947109 DOI: 10.1111/ceo.14190] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 10/26/2022] [Accepted: 11/04/2022] [Indexed: 11/11/2022]
Abstract
Diabetic retinopathy is the most feared complication for those with diabetes. Although visible vascular pathology traditionally defines the management of this condition, it is now recognised that a range of cellular changes occur in the retina from an early stage of diabetes. One of the most significant functional changes that occurs in those with diabetes is a loss of vasoregulation in response to changes in neural activity. There are several retinal cell types that are critical for mediating so-called neurovascular coupling, including Müller cells, microglia and pericytes. Although there is a great deal of evidence that suggests that Müller cells are integral to regulating the vasculature, they only modulate part of the vascular tree, highlighting the complexity of vasoregulation within the retina. Recent studies suggest that retinal immune cells, microglia, play an important role in mediating vasoconstriction. Importantly, retinal microglia contact both the vasculature and neural synapses and induce vasoconstriction in response to neurally expressed chemokines such as fractalkine. This microglial-dependent regulation occurs via the vasomediator angiotensinogen. Diabetes alters the way microglia regulate the retinal vasculature, by increasing angiotensinogen expression, causing capillary vasoconstriction and contributing to a loss of vascular reactivity to physiological signals. This article summarises recent studies showing changes in vascular regulation during diabetes, the potential mechanisms by which this occurs and the significance of these early changes to the progression of diabetic retinopathy.
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Affiliation(s)
- Erica L. Fletcher
- Department of Anatomy and PhysiologyThe University of MelbourneMelbourneVictoriaAustralia
| | - Michael A. Dixon
- Department of Anatomy and PhysiologyThe University of MelbourneMelbourneVictoriaAustralia
| | - Samuel A. Mills
- Department of Anatomy and Developmental BiologyMonash UniversityMelbourneVictoriaAustralia
| | - Andrew I. Jobling
- Department of Anatomy and PhysiologyThe University of MelbourneMelbourneVictoriaAustralia
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18
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Cabral D, Ramtohul P, Zatreanu L, Galhoz D, Leitao M, Nogueira V, Sarraf D, Freund KB. Deep Capillary Plexus Features in Acute Macular Neuroretinopathy: Novel Insights Based on the Anatomy of Henle Fiber Layer. Invest Ophthalmol Vis Sci 2022; 63:4. [PMID: 36469026 PMCID: PMC9730735 DOI: 10.1167/iovs.63.13.4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
PURPOSE The purpose of this study was to identify a precise location of deep capillary plexus (DCP) injury in acute macular neuroretinopathy (AMN) lesions using multimodal imaging. METHODS En face structural optical coherence tomography (OCT) images were manually segmented to delineate outer retinal AMN lesions involving the ellipsoid zone and interdigitation zone. AMN lesion centroid was calculated, and image distortion was applied to correct for Henle fiber layer (HFL) length and orientation. The resulting image was registered with the corresponding en face OCT angiography (OCTA) image segmented at the DCP and structural OCT volume before grading for vascular and structural features, respectively. RESULTS Thirty-nine AMN lesions from 16 eyes (11 female patients, mean age 34 ± 4 years) were analyzed. After correcting for HFL anatomy, in 62% of AMN lesions, the centroid co-localized with a capillary vortex (pattern 1); flow defects were detected in 33% of lesions (pattern 2); and in 5% of lesions no specific pattern could be identified (pattern 3). The detection of a specific pattern increased after correcting the projection of AMN lesion for HFL anatomy (28% vs. 5%, P = 0.04). Outer nuclear layer thickness was lower in the centroid area in 10 (29%) AMN lesions from 6 patients, all corresponding to lesions fitting pattern 2 (r = 0.78, P < 0.001). CONCLUSIONS AMN lesions might be a result of DCP impairment at the level of the capillary vortex or draining venule. In eyes with AMN, the location of outer retinal changes associated with DCP ischemia appears to be influenced by the length and orientation of HFL.
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Affiliation(s)
- Diogo Cabral
- Vitreous Retina Macula Consultants of New York, New York, New York, United States,iNOVA4Health, NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Prithvi Ramtohul
- Vitreous Retina Macula Consultants of New York, New York, New York, United States
| | - Luca Zatreanu
- Rochester Regional Health, Rochester, New York, United States
| | - Daniel Galhoz
- iNOVA4Health, NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal,Instituto Superior Tecnico, Universidade de Lisboa, Lisbon, Portugal
| | - Miguel Leitao
- Instituto de Oftalmologia Dr. Gama Pinto, Lisbon, Portugal
| | - Vanda Nogueira
- Instituto de Oftalmologia Dr. Gama Pinto, Lisbon, Portugal
| | - David Sarraf
- Retinal Disorders and Ophthalmic Genetics Division, Stein Eye Institute, University of California, Los Angeles, Los Angeles, California, United States
| | - K. Bailey Freund
- Vitreous Retina Macula Consultants of New York, New York, New York, United States,Department of Ophthalmology, NYU Grossman School of Medicine, New York, New York, United States
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Retinal ischemic cascade: New insights into the pathophysiology and imaging findings. Surv Ophthalmol 2022; 68:380-387. [PMID: 36464134 DOI: 10.1016/j.survophthal.2022.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 11/26/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022]
Abstract
Retinal ischemia gives rise to a complex spectrum in which the cumulative profile of ischemia of the middle and inner retina can be highly variable. We reviewed the current knowledge on paracentral acute middle maculopathy (PAMM) pathophysiology and accompanying risk factors, the middle and inner retinal vasculature and blood flow, and the vulnerability of the middle retina in vaso-occlusive disorders. The inner nuclear layer (INL) is easily affected by slight degrees of retinal hypoperfusion and ischemia. INL infarction starts at perivenular sites, manifesting as skip PAMM lesions and a fern-like appearance in cross-sectional and en face views, respectively. With horizontal progression, INL infarction may develop into diffuse globular PAMM. If vertical progression occurs, the entire middle and inner portions of the retina can be affected. Transmural infarction of the middle and inner retina would be at the end of this spectrum. This gradient of ischemic progression resembles an ischemic cascade. We review the evidence supporting the term "retinal ischemic cascade," which encompasses a broad continuum of manifestations with roots in middle retinal infarction. With this terminology, variations in spatial and temporal progression and resolution of ischemia can also be delivered; it further enables addressing the possible associations between the middle and inner retinal ischemic patterns.
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20
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Hao J, Shen T, Zhu X, Liu Y, Behera A, Zhang D, Chen B, Liu J, Zhang J, Zhao Y. Retinal Structure Detection in OCTA Image via Voting-Based Multitask Learning. IEEE TRANSACTIONS ON MEDICAL IMAGING 2022; 41:3969-3980. [PMID: 36044489 DOI: 10.1109/tmi.2022.3202183] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Automated detection of retinal structures, such as retinal vessels (RV), the foveal avascular zone (FAZ), and retinal vascular junctions (RVJ), are of great importance for understanding diseases of the eye and clinical decision-making. In this paper, we propose a novel Voting-based Adaptive Feature Fusion multi-task network (VAFF-Net) for joint segmentation, detection, and classification of RV, FAZ, and RVJ in optical coherence tomography angiography (OCTA). A task-specific voting gate module is proposed to adaptively extract and fuse different features for specific tasks at two levels: features at different spatial positions from a single encoder, and features from multiple encoders. In particular, since the complexity of the microvasculature in OCTA images makes simultaneous precise localization and classification of retinal vascular junctions into bifurcation/crossing a challenging task, we specifically design a task head by combining the heatmap regression and grid classification. We take advantage of three different en face angiograms from various retinal layers, rather than following existing methods that use only a single en face. We carry out extensive experiments on three OCTA datasets acquired using different imaging devices, and the results demonstrate that the proposed method performs on the whole better than either the state-of-the-art single-purpose methods or existing multi-task learning solutions. We also demonstrate that our multi-task learning method generalizes across other imaging modalities, such as color fundus photography, and may potentially be used as a general multi-task learning tool. We also construct three datasets for multiple structure detection, and part of these datasets with the source code and evaluation benchmark have been released for public access.
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21
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The OCT angular sign of Henle fiber layer (HFL) hyperreflectivity (ASHH) and the pathoanatomy of the HFL in macular disease. Prog Retin Eye Res 2022:101135. [DOI: 10.1016/j.preteyeres.2022.101135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/08/2022] [Accepted: 10/12/2022] [Indexed: 11/11/2022]
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22
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Ramtohul P, Iovino C, Au A, Bacci T, Pichi F, Corradetti G, Corvi F, Manoharan N, Marin AI, Tadayoni R, Sadda S, Freund KB, Sarraf D. Clinical and Morphologic Characteristics of Perivenular Fernlike Leakage on Ultrawide-field Fluorescein Angiography. Ophthalmol Retina 2022; 6:1070-1079. [PMID: 35545196 DOI: 10.1016/j.oret.2022.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 05/02/2022] [Accepted: 05/03/2022] [Indexed: 06/15/2023]
Abstract
PURPOSE To analyze the spectrum of the perivenular fernlike leakage on ultrawide-field fluorescein angiography (UWFA) and discuss its potential implications in the current understanding of the retinal venous outflow. DESIGN Retrospective, observational case series. PARTICIPANTS Eyes presenting with fernlike patterns of dye leakage on UWFA were included in this study. METHODS Analysis of the clinical characteristics and multimodal imaging findings using UWFA and wide-angle swept-source OCT-angiography (SS-OCTA). MAIN OUTCOME MEASURES The disease spectrum, anatomic origin, and clinical implications of this fernlike leakage. RESULTS Multimodal retinal images from 40 eyes of 29 patients with fernlike leakage on UWFA were studied. The underlying etiologies included a wide range of inflammatory disorders, including pars planitis (18 eyes) and central retinal vein occlusion (2 eyes). On UWFA, the fernlike leakage originated from the retinal capillaries and venules directly adjacent to the veins and spared the periarterial zone. This perivenular fernlike leakage involved the far periphery in all cases and progressed more diffusely and centripetally in cases with more severe intraocular inflammation. On wide-angle SS-OCTA, the impairment of deep capillary plexus (DCP) flow signals precisely colocalized with the perivenular fernlike leakages identified on UWFA. CONCLUSIONS The fernlike leakage on UWFA refers to the distinctive perivenular dye leakage that originates from the retinal capillaries and venules. Multimodal imaging correlation suggests that the predominant impairment is at the level of the DCP. The axial symmetry of the fernlike leakage with the veins and sparing of the periarterial zone may support the dominant venous role of the DCP.
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Affiliation(s)
- Prithvi Ramtohul
- Centre Hospitalier Universitaire de l'Hôpital Nord, chemin des Bourrely, Marseille, France; Vitreous Retina Macula Consultants of New York, New York, New York
| | - Claudio Iovino
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Adrian Au
- Stein Eye Institute, University of California Los Angeles, Los Angeles, California
| | - Tommaso Bacci
- Vitreous Retina Macula Consultants of New York, New York, New York; Ophthalmology Unit, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena University Hospital, Siena, Italy
| | - Francesco Pichi
- Eye Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates; Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Giulia Corradetti
- Department of Ophthalmology, Doheny Image Reading Center, Doheny Eye Institute, University of California Los Angeles (UCLA) Affiliated, Los Angeles, California
| | - Federico Corvi
- Department of Ophthalmology, Doheny Image Reading Center, Doheny Eye Institute, University of California Los Angeles (UCLA) Affiliated, Los Angeles, California
| | - Niranjan Manoharan
- Department of Ophthalmology, University of Colorado School of Medicine, Aurora, Colorado
| | - Alejandro Itzam Marin
- Department of Ophthalmology, University of Colorado School of Medicine, Aurora, Colorado
| | - Ramin Tadayoni
- Université de Paris, Ophthalmology Department, AP-HP, Hôpital Lariboisière, Paris, France; Hôpital Fondation Adolphe de Rothschild, 75019, Paris, France
| | - SriniVas Sadda
- Department of Ophthalmology, Doheny Image Reading Center, Doheny Eye Institute, University of California Los Angeles (UCLA) Affiliated, Los Angeles, California
| | - K Bailey Freund
- Vitreous Retina Macula Consultants of New York, New York, New York; Department of Ophthalmology, NYU Grossman School of New York, New York, New York
| | - David Sarraf
- Stein Eye Institute, University of California Los Angeles, Los Angeles, California.
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23
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Balaratnasingam C, An D, Hein M, Yu P, Yu DY. Studies of the retinal microcirculation using human donor eyes and high-resolution clinical imaging: Insights gained to guide future research in diabetic retinopathy. Prog Retin Eye Res 2022; 94:101134. [PMID: 37154065 DOI: 10.1016/j.preteyeres.2022.101134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 09/18/2022] [Accepted: 10/03/2022] [Indexed: 11/06/2022]
Abstract
The microcirculation plays a key role in delivering oxygen to and removing metabolic wastes from energy-intensive retinal neurons. Microvascular changes are a hallmark feature of diabetic retinopathy (DR), a major cause of irreversible vision loss globally. Early investigators have performed landmark studies characterising the pathologic manifestations of DR. Previous works have collectively informed us of the clinical stages of DR and the retinal manifestations associated with devastating vision loss. Since these reports, major advancements in histologic techniques coupled with three-dimensional image processing has facilitated a deeper understanding of the structural characteristics in the healthy and diseased retinal circulation. Furthermore, breakthroughs in high-resolution retinal imaging have facilitated clinical translation of histologic knowledge to detect and monitor progression of microcirculatory disturbances with greater precision. Isolated perfusion techniques have been applied to human donor eyes to further our understanding of the cytoarchitectural characteristics of the normal human retinal circulation as well as provide novel insights into the pathophysiology of DR. Histology has been used to validate emerging in vivo retinal imaging techniques such as optical coherence tomography angiography. This report provides an overview of our research on the human retinal microcirculation in the context of the current ophthalmic literature. We commence by proposing a standardised histologic lexicon for characterising the human retinal microcirculation and subsequently discuss the pathophysiologic mechanisms underlying key manifestations of DR, with a focus on microaneurysms and retinal ischaemia. The advantages and limitations of current retinal imaging modalities as determined using histologic validation are also presented. We conclude with an overview of the implications of our research and provide a perspective on future directions in DR research.
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Affiliation(s)
- Chandrakumar Balaratnasingam
- Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia; Department of Ophthalmology, Sir Charles Gairdner Hospital, Western Australia, Australia.
| | - Dong An
- Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia
| | - Martin Hein
- Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia
| | - Paula Yu
- Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia
| | - Dao-Yi Yu
- Lions Eye Institute, Nedlands, Western Australia, Australia; Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia
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Cabral D, Fradinho AC, Pereira T, Ramakrishnan MS, Bacci T, An D, Tenreiro S, Seabra MC, Balaratnasingam C, Freund KB. Macular Vascular Imaging and Connectivity Analysis Using High-Resolution Optical Coherence Tomography. Transl Vis Sci Technol 2022; 11:2. [PMID: 35648637 PMCID: PMC9172017 DOI: 10.1167/tvst.11.6.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 05/06/2022] [Indexed: 11/24/2022] Open
Abstract
Purpose To characterize macular blood flow connectivity in vivo using high-resolution optical coherence tomography (HighRes OCT). Methods Cross-sectional, observational study. Dense (6-µm interscan distance) perifoveal HighRes OCT raster scans were performed on healthy participants. To mitigate the limitations of projection-resolved OCT-angiography, flow and structural data were used to observe the vascular structures of the superficial vascular complex (SVC) and the deep vascular complex. Vascular segmentation and rendering were performed using Imaris 9.5 software. Inflow and outflow patterns were classified according to vascular diameter and branching order from superficial arteries and veins, respectively. Results Eight eyes from eight participants were included in this analysis, from which 422 inflow and 459 outflow connections were characterized. Arteries had direct arteriolar connections to the SVC (78%) and to the intermediate capillary plexus (ICP, 22%). Deep capillary plexus (DCP) inflow derived from small-diameter vessels succeeding ICP arterioles. The most prevalent outflow pathways coursed through superficial draining venules (74%). DCP draining venules ordinarily merged with ICP draining venules and drained independently of superficial venules in 21% of cases. The morphology of DCP draining venules in structural HighRes OCT is distinct from other vessels crossing the inner nuclear layer and can be used to identify superficial veins. Conclusions Vascular connectivity analysis supports a hybrid circuitry of blood flow within the human parafoveal macula. Translational Relevance Characterization of parafoveal macular blood flow connectivity in vivo using a precise segmentation of HighRes OCT is consistent with ground-truth microscopy studies and shows a hybrid circuitry.
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Affiliation(s)
- Diogo Cabral
- Vitreous Retina Macula Consultants of New York, NY, USA
- CEDOC, NOVA Medical School I Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Ana C. Fradinho
- CEDOC, NOVA Medical School I Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Telmo Pereira
- CEDOC, NOVA Medical School I Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal
| | | | - Tommaso Bacci
- Vitreous Retina Macula Consultants of New York, NY, USA
| | - Dong An
- Centre for Ophthalmology and Visual Science, University of Western Australia, Nedlands, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Sandra Tenreiro
- CEDOC, NOVA Medical School I Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal
| | - Miguel C. Seabra
- CEDOC, NOVA Medical School I Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal
- UCL Institute of Ophthalmology, London, UK
| | - Chandrakumar Balaratnasingam
- Centre for Ophthalmology and Visual Science, University of Western Australia, Nedlands, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
| | - K. Bailey Freund
- Vitreous Retina Macula Consultants of New York, NY, USA
- Department of Ophthalmology, NYU Grossman School of Medicine, New York, NY, USA
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An D, Chung-Wah-Cheong J, Yu DY, Balaratnasingam C. Alpha-Smooth Muscle Actin Expression and Parafoveal Blood Flow Pathways Are Altered in Preclinical Diabetic Retinopathy. Invest Ophthalmol Vis Sci 2022; 63:8. [PMID: 35522303 PMCID: PMC9078056 DOI: 10.1167/iovs.63.5.8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate differences in alpha smooth muscle actin (αSMA) expression and parafoveal blood flow pathways in diabetic retinopathy (DR). Methods Human donor eyes from healthy subjects (n = 8), patients with diabetes but no DR (DR-; n = 7), and patients with clinical DR (DR+; n = 13) were perfusion labeled with antibodies targeting αSMA, lectin, collagen IV, and filamentous actin. High-resolution confocal scanning laser microscopy was used to quantify αSMA staining and capillary density in the parafoveal circulation. Quantitative analyses of connections between retinal arteries and veins within the superficial vascular plexus (SVP), intermediate capillary plexus (ICP) and deep capillary plexus (DCP) were performed. Results Mean age between the groups was not different (P = 0.979). αSMA staining was seen in the SVP and ICP of all groups. The DCP was predominantly devoid of αSMA staining in control eyes but increased in a disease stage-specific manner in the DR- and DR+ groups. The increase in αSMA staining was localized to pericytes and endothelia of terminal arterioles and adjacent capillary segments. Capillary density was less in the DCP in the DR+ group (P < 0.001). ICP of the DR- and DR+ groups received more direct arteriole supplies than the control group (P < 0.001). Venous outflow pathways were not altered (all P > 0.284). Conclusions Alterations in αSMA and vascular inflow pathways in preclinical DR suggest that perfusion abnormalities precede structural vascular changes such as capillary loss. Preclinical DR may be characterized by a "steal" phenomenon where blood flow is preferentially diverted from the SVP to the ICP and DCP.
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Affiliation(s)
- Dong An
- Lions Eye Institute, Nedlands, Western Australia, Australia.,Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Western Australia, Australia
| | | | - Dao-Yi Yu
- Lions Eye Institute, Nedlands, Western Australia, Australia.,Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Western Australia, Australia
| | - Chandrakumar Balaratnasingam
- Lions Eye Institute, Nedlands, Western Australia, Australia.,Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Western Australia, Australia.,Department of Ophthalmology, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
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Intensity distribution segmentation in ultrafast Doppler combined with scanning laser confocal microscopy for assessing vascular changes associated with ageing in murine hippocampi. Sci Rep 2022; 12:6784. [PMID: 35473942 PMCID: PMC9042937 DOI: 10.1038/s41598-022-10457-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 04/06/2022] [Indexed: 11/21/2022] Open
Abstract
The hippocampus plays an important role in learning and memory, requiring high-neuronal oxygenation. Understanding the relationship between blood flow and vascular structure—and how it changes with ageing—is physiologically and anatomically relevant. Ultrafast Doppler (\documentclass[12pt]{minimal}
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\begin{document}$$\mu$$\end{document}μDoppler) and scanning laser confocal microscopy (SLCM) are powerful imaging modalities that can measure in vivo cerebral blood volume (CBV) and post mortem vascular structure, respectively. Here, we apply both imaging modalities to a cross-sectional and longitudinal study of hippocampi vasculature in wild-type mice brains. We introduce a segmentation of CBV distribution obtained from \documentclass[12pt]{minimal}
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\begin{document}$$\mu$$\end{document}μDoppler and show that this mice-independent and mesoscopic measurement is correlated with vessel volume fraction (VVF) distribution obtained from SLCM—e.g., high CBV relates to specific vessel locations with large VVF. Moreover, we find significant changes in CBV distribution and vasculature due to ageing (5 vs. 21 month-old mice), highlighting the sensitivity of our approach. Overall, we are able to associate CBV with vascular structure—and track its longitudinal changes—at the artery-vein, venules, arteriole, and capillary levels. We believe that this combined approach can be a powerful tool for studying other acute (e.g., brain injuries), progressive (e.g., neurodegeneration) or induced pathological changes.
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Iovino C, Au A, Ramtohul P, Bacci T, AlBahlal A, Khan AM, Al-Abdullah AA, Wendel R, Chhablani J, Sadda S, Freund KB, Sarraf D. Coincident PAMM and AMN and Insights Into a Common Pathophysiology. Am J Ophthalmol 2022; 236:136-146. [PMID: 34283978 DOI: 10.1016/j.ajo.2021.07.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/29/2021] [Accepted: 07/06/2021] [Indexed: 11/01/2022]
Abstract
PURPOSE To analyze imaging characteristics and the clinical course of patients demonstrating coincident lesions of paracentral acute middle maculopathy (PAMM) and acute macular neuroretinopathy (AMN) in the same eye. DESIGN Retrospective, observational case series. METHODS Lesions from patients presenting with coincident PAMM and AMN in the same eye were evaluated with multimodal imaging including optical coherence tomography (OCT). The association with ocular and systemic findings was also investigated. RESULTS Fifteen subjects (17 eyes) were included in the study. The mean age was 44.4 ± 15.3 years and the follow-up period ranged from 1 to 32 weeks (mean, 11.9 ± 11.4 weeks). The mean visual acuity was 0.8 ± 0.6 logarithm of minimal angle of resolution (Snellen equivalent 20/126) at baseline and 0.3 ± 0.4 logarithm of minimal angle of resolution (Snellen equivalent 20/40) at the last follow-up. PAMM and AMN lesions occurred in the setting of Purtscher's retinopathy (4 eyes, 3 patients), retinal vein occlusion (7 eyes, 7 patients), central retinal artery occlusion (1 eye, 1 patient), and idiopathic retinal vasculitis (1 eye, 1 patient). In 4 eyes (3 patients), an association with other ocular disorders was not identified as evaluated with multimodal imaging. Of the total cohort, 11 eyes (64.7%) showed extension of the AMN hyperreflective bands in Henle's fiber layer with a Z-shaped morphology on OCT B-scan. CONCLUSIONS The presence of coincident PAMM and AMN suggests a common pathophysiologic etiology. This may be the result of retinal vein impairment and hypoperfusion at the level of the deep retinal capillary plexus possibly leading to injury to the Müller glia or photoreceptors in Henle's fiber layer.
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An D, Tan B, Yu DY, Balaratnasingam C. Differentiating Microaneurysm Pathophysiology in Diabetic Retinopathy Through Objective Analysis of Capillary Nonperfusion, Inflammation, and Pericytes. Diabetes 2022; 71:733-746. [PMID: 35043147 PMCID: PMC9375447 DOI: 10.2337/db21-0737] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 12/27/2021] [Indexed: 11/13/2022]
Abstract
Microaneurysms are biomarkers of microvascular injury in diabetic retinopathy (DR). Impaired retinal capillary perfusion is a critical pathogenic mechanism in the development of microvascular abnormalities. Targeting fundamental molecular disturbances resulting from capillary nonperfusion, such as increased vascular endothelial growth factor expression, does not always reverse the anatomic complications of DR, suggesting that other pathogenic mechanisms independent of perfusion also play a role. We stratify the effects of capillary nonperfusion, inflammation, and pericyte loss on microaneurysm size and leakage in DR through three-dimensional analysis of 636 microaneurysms using high-resolution confocal scanning laser microscopy. Capillary nonperfusion, pericyte loss, and inflammatory cells were found to be independent predictors of microaneurysm size. Nonperfusion alone without pericyte loss or inflammation was not a significant predictor of microaneurysm leakage. Microaneurysms found in regions without nonperfusion were significantly smaller than those found in regions with nonperfusion, and their size was not associated with pericyte loss or inflammation. In addition, microaneurysm size was a significant predictor of leakage in regions with nonperfusion only. This report refines our understanding of the disparate pathophysiologic mechanisms in DR and provides a histologic rationale for understanding treatment failure for microvascular complications in DR.
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Affiliation(s)
- Dong An
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Bryan Tan
- Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Dao-Yi Yu
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Chandrakumar Balaratnasingam
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
- Department of Ophthalmology, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
- Corresponding author: Chandrakumar Balaratnasingam,
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29
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Ong JX, Fawzi AA. Perspectives on diabetic retinopathy from advanced retinal vascular imaging. Eye (Lond) 2022; 36:319-327. [PMID: 34987198 PMCID: PMC8807653 DOI: 10.1038/s41433-021-01825-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 10/05/2021] [Accepted: 10/14/2021] [Indexed: 02/03/2023] Open
Abstract
Diabetic retinopathy (DR) is a microvascular complication of diabetes and the most common cause of acquired vision loss in adults worldwide. DR is associated with long-term chronic hyperglycaemia and its detrimental effects on the neurovascular structure and function of the retina. Direct imaging of the retinal vasculature and staging of DR has been traditionally based on fundoscopy and fluorescein angiography, which provide only 2D views of the retina, and in the case of fluorescein angiography, requires an invasive dye injection. In contrast, advanced retinal imaging modalities like optical coherence tomography angiography (OCTA) and adaptive optics (AO) are non-invasive and provide depth-resolved, 3D visualization of retinal vessel structure as well as blood flow. Recent studies utilizing these imaging techniques have shown promise in evaluating quantitative vascular parameters that correlate tightly to clinical DR staging, elucidating functional changes in early diabetes, and monitoring DR treatment response. In this article, we discuss and synthesize the results of advanced retinal imaging studies in DR and their implications for our clinical and pathophysiologic understanding of the disease. Based on the recent literature, we also propose a model to describe the differential changes in vascular structure and flow that have been described on advanced retinal imaging as DR progresses. Future studies of these imaging modalities in larger and more diverse populations, as well as corroboration with histological and functional studies, will be important to further our understanding of DR.
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Affiliation(s)
- Janice X Ong
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Amani A Fawzi
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
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Duan J, Li M, Wu Z, Zhang Z. Total venous nature of retinal deep capillary plexus inferred by continuity of prominent middle limiting membrane sign in optical coherence tomography. PLoS One 2021; 16:e0257698. [PMID: 34547044 PMCID: PMC8454985 DOI: 10.1371/journal.pone.0257698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 09/07/2021] [Indexed: 11/21/2022] Open
Abstract
This study aimed to theoretically identify the vascular nature of the deep capillary plexus (DCP) by examining patients presenting with both paracentral acute middle maculopathy (PAMM) and prominent middle limiting membrane (p-MLM) sign and p-MLM sign alone in spectral-domain optical coherence tomography (SD-OCT). A retrospective review of the medical records of patients with retinal vein or artery occlusion from two tertiary medical centers was performed. Consecutive patients with a clinical diagnosis of all categories of retinal artery occlusion (RAO) and retinal vein occlusion (RVO) (branch or central and ischemic or non-ischemic) who had undergone SD-OCT imaging from January 2015 to May 2020 were recruited and their p-MLM signs and PAMM lesions were assessed. We included 118 patients who presented with p-MLM sign with or without PAMM lesions. Amon them, 40 were female and 78 were male, with a mean age of 61.1 years. Of the 109 patients with both p-MLM sign and PAMM lesions, 23 had branch RAO, two had branch RVO, 67 had central RAO, 13 had central RVO, and four had a combination of central RAO and central RVO. All nine patients with the p-MLM sign alone had central RVO accompanied by cystoid macular edema. In all the enrolled patients, the hyperreflective lines of the p-MLM sign were continuous, regardless of the type of PAMM lesions. In conclusion, when PAMM and p-MLM sign are examined together, further proof regarding the possible complete venous nature of the vasculature of the retinal DCP might be speculated.
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Affiliation(s)
- Jialiang Duan
- Department of Ophthalmology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, People’s Republic of China
| | - Minhao Li
- Department of Ophthalmology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, People’s Republic of China
| | - Zhifeng Wu
- Department of Ophthalmology, Affiliated Wuxi Clinical College of Nantong University, Wuxi, Jiangsu Province, People’s Republic of China
- Department of Ophthalmology, The Affiliated Wuxi No.2 People’s Hospital of Nanjing Medical University, Wuxi, Jiangsu Province, People’s Republic of China
| | - Zhengwei Zhang
- Department of Ophthalmology, Affiliated Wuxi Clinical College of Nantong University, Wuxi, Jiangsu Province, People’s Republic of China
- Department of Ophthalmology, The Affiliated Wuxi No.2 People’s Hospital of Nanjing Medical University, Wuxi, Jiangsu Province, People’s Republic of China
- * E-mail:
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Lin BR, Lin F, Su L, Nassisi M, Sadda SR, Gaw SL, Tsui I. Relative Postpartum Retinal Vasoconstriction Detected With Optical Coherence Tomography Angiography. Transl Vis Sci Technol 2021; 10:40. [PMID: 34003925 PMCID: PMC7910633 DOI: 10.1167/tvst.10.2.40] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Purpose To characterize changes in retinal perfusion during pregnancy and the postpartum period using optical coherence tomography angiography (OCTA). Methods A nonmydriatic OCTA camera was used to image healthy women who were pregnant or in the postpartum period along with nonpregnant controls. Perfusion density (PD) and vessel length density (VLD) in the superficial capillary plexus (SCP), intermediate capillary plexus (ICP), and deep capillary plexus (DCP) were evaluated. Results A total of 16, 15, and 13 eyes from nonpregnant, pregnant, and healthy postpartum subjects, respectively, were evaluated. When compared to controls, there were significant increases in ICP PD during the second and third trimester of pregnancy, along with significant decreases in both PD and VLD in SCP, ICP, and DCP up to 14 weeks postpartum. Conclusions During pregnancy, vascular changes consistent with retinal vasodilation were noted in the ICP. During the postpartum period, changes in retinal vasculature suggest relative vasoconstriction involving all three layers when compared to both the pregnant and nonpregnant states. Translational Relevance Detecting postpartum changes in retinal vasculature could offer important insights into postpartum physiology throughout the body.
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Affiliation(s)
- Benjamin R Lin
- Bascom Palmer Eye Institute, Miami, FL, USA.,David Geffen School of Medicine, Los Angeles, CA, USA
| | - Fei Lin
- David Geffen School of Medicine, Los Angeles, CA, USA
| | - Li Su
- Doheny Eye Center and UCLA Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Marco Nassisi
- Doheny Eye Center and UCLA Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - SriniVas R Sadda
- Doheny Eye Center and UCLA Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Stephanie L Gaw
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of California San Francisco, San Francisco, CA, USA
| | - Irena Tsui
- Doheny Eye Center and UCLA Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, USA
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Clinical Characteristics of Paracentral Acute Middle Maculopathy in Eyes with Retinal Vascular Occlusion Diseases in Chinese Patients. J Ophthalmol 2021; 2021:8867570. [PMID: 34239722 PMCID: PMC8235965 DOI: 10.1155/2021/8867570] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 06/06/2021] [Accepted: 06/12/2021] [Indexed: 11/28/2022] Open
Abstract
Aim To investigate the incidence and clinical characteristics of paracentral acute middle maculopathy (PAMM) and its relationship with prominent middle limiting membrane (p-MLM) sign in eyes with retinal artery occlusion (RAO) or retinal vein occlusion (RVO) in a Chinese clinical setting. Methods In this retrospective observational study from January 2015 to May 2020, multimodal imaging data of 807 eyes including 555 consecutive patients with RVO or 252 consecutive patients with RAO were reviewed. All patients were scanned using the spectrum-domain optical coherence tomography (OCT), and some of them underwent color fundus photography, fundus fluorescence angiography, en face OCT, and OCT angiography. Results PAMM was detected in 49 eyes of 49 RAO patients and 29 eyes of 29 RVO patients. The mean ages at presentation were 64.49 ± 13.90 years and 54.00 ± 18.48 years in RAO and RVO patients (P=0.006), respectively. Eyes with RAO were more prone to develop PAMM (19.44% [49/252] vs. 5.23% [29/555]; P < 0.001). Of the 78 eyes with PAMM, 24 eyes (7 eyes with RVO and 17 eyes with RAO) were found with p-MLM sign. An interesting phenomenon that had been overlooked before was that the hyperreflective line of the p-MLM sign was usually continuous, regardless of the type of PAMM lesion. Conclusions This series is the largest to date to describe the clinical characteristics of PAMM and p-MLM sign in Chinese patients. The incidence of PAMM and p-MLM sign in patients with RAO was relatively higher than that in patients with RVO. These signs alone probably represent milder ischemia and prompt us to carry out a comprehensive and meticulous examination to prevent the further development of the disease. In addition, the hyperreflective line of the p-MLM sign was usually continuous, which could support the totally venous nature of the retinal deep capillary plexus to some extent.
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Fragiotta S, Ciancimino C, Perdicchi A, de Paula A, Abdolrahimzadeh S, Scuderi G. Volume Rendering of Angiographic Optical Coherence Tomography Angiography in Fovea Plana and Normal Foveal Pit. Front Neurol 2021; 12:633492. [PMID: 33986716 PMCID: PMC8111301 DOI: 10.3389/fneur.2021.633492] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 03/11/2021] [Indexed: 12/13/2022] Open
Abstract
This paper aims to study adaptative vascular arrangements in idiopathic fovea plana with volume-rendered optical coherence tomography angiography (OCTA). A retrospective review of two cases of idiopathic fovea plana (mean age: 26.5 years) and two age-matched controls imaged with OCTA was conducted using spectral-domain OCTA (RTVue XR Avanti, Optovue, Inc., Fremont, CA) equipped with the AngioVue software. Both en face OCTA slabs and OCTA b scans were processed through Fiji software (http://fiji.sc; software version 2.0.0-rc-68/1.52e), and then extracted as image sequences for volume rendering reconstructions using the ImageVis3D volume rendering system (3.1.0 release). Eyes with idiopathic fovea plana demonstrated a regular superficial vascular plexus connecting to a single vascular monolayer representing the deeper vascular plexuses. At this location, several vertical short path connections were demonstrated, in contraposition with normal eyes where short path connections were infrequently observed. Advances in three-dimensional OCTA reconstruction increase the understanding of vascular connections and arrangement in retinal plexuses and possible anatomical variations that cannot be detected with conventional two-dimensional b scans.
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Affiliation(s)
- Serena Fragiotta
- Ophthalmology Unit, Department of Neurosciences, Mental Health, and Sensory Organs (NESMOS), St. Andrea Hospital, University of Rome "La Sapienza", Rome, Italy
| | - Chiara Ciancimino
- Ophthalmology Unit, Department of Neurosciences, Mental Health, and Sensory Organs (NESMOS), St. Andrea Hospital, University of Rome "La Sapienza", Rome, Italy
| | - Andrea Perdicchi
- Ophthalmology Unit, Department of Neurosciences, Mental Health, and Sensory Organs (NESMOS), St. Andrea Hospital, University of Rome "La Sapienza", Rome, Italy
| | | | - Solmaz Abdolrahimzadeh
- Ophthalmology Unit, Department of Neurosciences, Mental Health, and Sensory Organs (NESMOS), St. Andrea Hospital, University of Rome "La Sapienza", Rome, Italy
| | - Gianluca Scuderi
- Ophthalmology Unit, Department of Neurosciences, Mental Health, and Sensory Organs (NESMOS), St. Andrea Hospital, University of Rome "La Sapienza", Rome, Italy
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Yu PK, Mehnert A, Athwal A, Sarunic MV, Yu DY. Use of the Retinal Vascular Histology to Validate an Optical Coherence Tomography Angiography Technique. Transl Vis Sci Technol 2021; 10:29. [PMID: 33520424 PMCID: PMC7817878 DOI: 10.1167/tvst.10.1.29] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 12/15/2020] [Indexed: 12/29/2022] Open
Abstract
Purpose To determine the fidelity of optical coherence tomography angiography (OCTA) techniques by direct comparison of the retinal capillary network images obtained from the same region as imaged by OCTA and high-resolution confocal microscope. Method Ten porcine eyes were perfused with red blood cells for OCTA image acquisition from the area centralis and then perfusion-fixed, and the vessels were labeled for confocal imaging. Two approaches involving post-processing of two-dimensional projection images and vessel tracking on three dimensional image stacks were used to obtain quantitative measurements. Data collected include vessel density, length of visible vessel track, count of visible branch points, vessel track depth, vessel diameter, angle of vessel descent, and angle of dive for comparison and analysis. Results Comparing vascular images acquired from OCTA and confocal microscopy, we found (1) a good representation of the larger caliber retinal vessels, (2) an underrepresentation of retinal microvessels smaller than 10 µm and branch points in all four retinal vascular plexuses, particularly the intermediate capillary plexus, (3) reduced visibility associated with an increase in the angle of descent, (4) a tendency to loss visibility of vessel track at a branch point or during a sharp dive, and (5) a reduction in visibility with increase in retinal depth on OCTA images. Conclusions Current OCTA techniques can visualize the retinal capillary network, but some types of capillaries cannot be detected by OCTA, particularly in the middle to deeper layers. Translational Relevance The information indicates the limitation in clinical use and scopes for improvement in the current OCTA technologies.
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Affiliation(s)
- Paula K Yu
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia.,Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Andrew Mehnert
- Centre for Microscopy Characterisation and Analysis, University of Western Australia, Perth, Australia.,National Imaging Facility, Australia
| | - Arman Athwal
- Lions Eye Institute, Nedlands, Western Australia, Australia.,School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Marinko V Sarunic
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Dao-Yi Yu
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia.,Lions Eye Institute, Nedlands, Western Australia, Australia
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Cabral D, Pereira T, Ledesma-Gil G, Rodrigues C, Coscas F, Sarraf D, Freund KB. Volume Rendering of Dense B-Scan Optical Coherence Tomography Angiography to Evaluate the Connectivity of Macular Blood Flow. Invest Ophthalmol Vis Sci 2021; 61:44. [PMID: 32561927 PMCID: PMC7415320 DOI: 10.1167/iovs.61.6.44] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Purpose To characterize macular blood flow connectivity using volume rendering of dense B-scan (DB) optical coherence tomography angiography (OCTA) data. Methods This was a prospective, cross-sectional, observational study. DB OCTA perifoveal scans were performed on healthy subjects using the Spectralis HRA+OCT2. A volumetric projection artifact removal algorithm and customized filters were applied to raw OCTA voxel data. Volume rendering was performed using a workflow on Imaris 9.5 software. Vascular graphs were obtained from angiographic data using the algorithm threshold-loops. Superficial arteries and veins were identified from color fundus photographs and connections between adjacent arteries and veins displayed using the shortest path algorithm. Connective pathway locations were analyzed with cross-sectional OCT and OCTA to determine their course through the superficial vascular complex (SVC) and the deep vascular complex (DVC). Results Fourteen eyes from seven subjects (mean age: 28 ± 5 years; 3 women) were included in this analysis. One hundred and twenty-six vascular connections were analyzed. In all cases, the shortest path connections between superficial arteries and veins coursed through the DVC. We did not identify shortest path connections confined to the SVC. Conclusions Volumetric analysis of vascular connectivity supports a predominantly in-series arrangement of blood flow between the SVC and DVC within the human perifoveal macula.
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Scharf J, Freund KB, Sadda S, Sarraf D. Paracentral acute middle maculopathy and the organization of the retinal capillary plexuses. Prog Retin Eye Res 2020; 81:100884. [PMID: 32783959 DOI: 10.1016/j.preteyeres.2020.100884] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/09/2020] [Accepted: 07/10/2020] [Indexed: 02/07/2023]
Abstract
The retinal capillary vasculature serves the formidable role of supplying the metabolically active inner and middle retina. In the parafoveal region, the retinal capillary plexuses (RCP) are organized in a system of three capillary layers of varying retinal depths: the superficial capillary plexus (SCP), intermediate capillary plexus (ICP) and deep capillary plexus (DCP). While the dynamic flow through these plexuses is complex and not completely understood, current research points to a hybrid model that includes both parallel and in series components in which blood flows in a predominantly serial direction between the superficial vascular complex (SVC) and deep vascular complex (DVC). Each capillary plexus autoregulates independently, so that under most conditions the retinal vasculature supplies adequate blood flow and oxygen saturation at varying depths despite diverse environmental stressors. When the flow in the deep vascular complex (i.e. ICP and DCP) fails, an ischemic lesion referred to as Paracentral Acute Middle Maculopathy (PAMM) can be identified. PAMM is an optical coherence tomography (OCT) finding defined by the presence of a hyperreflective band at the level of the inner nuclear layer (INL) that indicates INL infarction caused by globally impaired perfusion through the retinal capillary system leading to hypoperfusion of the DVC or specifically the DCP. Patients present with an acute onset paracentral scotoma and typically experience a permanent visual defect. Lesions can be caused by a diverse set of local retinal vascular diseases and systemic disorders. PAMM is a manifestation of the retinal ischemic cascade in which the mildest forms of ischemia develop at the venular end of the DCP, i.e. perivenular PAMM, while more severe forms progress horizontally to diffusely involve the INL, and the most severe forms progress vertically to infarct the inner retina. Management is targeted toward the identification and treatment of related vasculopathic and systemic risk factors.
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Affiliation(s)
- Jackson Scharf
- Retina Disorders and Ophthalmic Genetics, Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, United States; Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - K Bailey Freund
- Retina Department, Vitreous Retina Macula Consultants of New York, New York, NY, United States
| | - SriniVas Sadda
- Doheny Image Reading Center, Doheny Eye Institute, University of California Los Angeles (UCLA) Affiliated, Los Angeles, CA, United States; Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - David Sarraf
- Retina Disorders and Ophthalmic Genetics, Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, United States; Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States; Greater Los Angeles VA Healthcare Center, Los Angeles, CA, United States.
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