scholarly journals Topology-Aware Retinal Artery–Vein Classification via Deep Vascular Connectivity Prediction

2020 ◽  
Vol 11 (1) ◽  
pp. 320
Author(s):  
Seung Yeon Shin ◽  
Soochahn Lee ◽  
Il Dong Yun ◽  
Kyoung Mu Lee
Keyword(s):  
Imaging Techniques ◽  
Systemic Diseases ◽  
Ocular Diseases ◽  
Vessel Segment ◽  
Vessel Structure ◽  
Retinal Artery ◽  
Voting Scheme ◽  
Effectiveness And Efficiency ◽  
Topology Estimation ◽  
Topological Error

Retinal artery–vein (AV) classification is a prerequisite for quantitative analysis of retinal vessels, which provides a biomarker for neurologic, cardiac, and systemic diseases, as well as ocular diseases. Although convolutional neural networks have presented remarkable performance on AV classification, it often comes with a topological error, like an abrupt class flipping on the same vessel segment or a weakness for thin vessels due to their indistinct appearances. In this paper, we present a new method for AV classification where the underlying vessel topology is estimated to give consistent prediction along the actual vessel structure. We cast the vessel topology estimation as iterative vascular connectivity prediction, which is implemented as deep-learning-based pairwise classification. In consequence, a whole vessel graph is separated into sub-trees, and each of them is classified as an artery or vein in whole via a voting scheme. The effectiveness and efficiency of the proposed method is validated by conducting experiments on two retinal image datasets acquired using different imaging techniques called DRIVE and IOSTAR.

Imaging Methods in Retinal Artery Occlusion

2020 ◽  
pp. 13-17
Keyword(s):  
Imaging Techniques ◽  
Retinal Artery Occlusion ◽  
Artery Occlusion ◽  
Sudden Onset ◽  
Diagnosis And Treatment ◽  
Fundus Fluorescein Angiography ◽  
Imaging Methods ◽  
Invasive Method ◽  
Retinal Microcirculation ◽  
Retinal Artery

Advances in ophthalmic imaging methods shed light on the management of retinal artery occlusion (RAO). RAT is an ocular emergency that can cause painless, sudden onset, unilateral vision, or loss of visual field. RAO requires early diagnosis and treatment. Fundus fluorescein angiography (FFA), which can be used in diagnosis and follow-up, is an invasive method requiring intravenous dye application which can cause side effects. In recent years, optical coherence tomography angiography (OCTA) has become widely available as an alternative to FFA in various ophthalmologic diseases. OCTA is a new type of angiography used for fundus imaging. It is a non-invasive method for measuring and quantifying the retinal microcirculation without the use of dyes. Many other imaging modalities used in ophthalmology clinics have been used in many areas of diagnosis and treatment of RAO patients. This review deals with the results of different imaging techniques in patients with RAO.

Genetic, Risk Factors, Pathogenesis and Systemic Diseases in Retinal Artery Occlusion

2020 ◽  
pp. 6-8
Keyword(s):  
Risk Factors ◽  
Contraceptive Use ◽  
Age Groups ◽  
Retinal Artery Occlusion ◽  
Artery Occlusion ◽  
Hereditary Diseases ◽  
Renal Diseases ◽  
Systemic Diseases ◽  
Protein C Deficiency ◽  
Retinal Artery

Retinal artery occlusions ( RAO) are considered an ocular emergency.  It has been estimated to occur with a frequency of about one per 10,000 outpatient visits. It is usually seen over the sixties and can be seen in younger age groups. Retinal artery occlusions are not hereditary diseases but can develop secondary to some hereditary diseases. The most important risk factors for RAO include smoking, oral contraceptive use, pregnancy, antiphospholipid syndrome, hyperhomocysteinemia, acquired protein c deficiency. RAO usually develops due to embolism. Embolic sources are mostly carotid arteries or cardiac origin. RAO is associated with many systemic diseases. The most important of these diseases are HT, DM, cardiovascular diseases, renal diseases, and temporal (giant cell) arteritis.

scholarly journals Perforated ray cells

1933 ◽  
Vol 113 (780) ◽  
pp. 82-92 ◽  
Keyword(s):  
The Other ◽  
Careful Study ◽  
Vessel Segment ◽  
Marginal Cell ◽  
Ray Cells ◽  
Vessel Structure ◽  
Fusiform Initials ◽  
Side Walls ◽  
Ray Cell ◽  
Lateral Walls

In certain woods, whose rays have extensive uniseriate margins, an individual marginal cell may sometimes be modified, by the perforation of its side walls, to connect two vessel segments on opposite sides of the ray. This feature does not appear to have been previously described though it is by no means uncommon; it has been observed by the authors in woods of many widely separated families. It is limited to woods with particular types of ray and vessel structure, but its occurrence seems to be primarily determined by the manner in which the vessels develop. Large ray cells which appeared to have scalariform perforations in the side walls were first observed by the authors in the wood of Lacistema aggregatum (Berg). Rusby. (Lacistemaceæ); examination of macerated material, fig. 1, has shown that the side walls of these cells are exactly similar to the end walls of the vessel segments, and though it has not been possible to demonstrate the absence of a membrane, the authors are convinced from a careful study of the sections, that these walls are actually perforated, and that each forms a link between two vertical series of vessel segments. The course of the vessel is unusual; instead of continuing up and down between the rays, it periodically passes obliquely through a ray, and continues on the other side. The ray is usually uniseriate at the point at which it is crossed, and the ray cell involved becomes slightly swollen, rather in the manner of an oil or mucilage cell but without visible contents. The lateral walls are perforated, so that the cell resembles a very short vessel segment, and presumably functions as such. From the position and shape of these cells, however, it is clear that they have been derived from ray initials and not from fusiform initials. Attention was first drawn to this phenomenon by the presence of scalariform bars in the walls of cells which, from their shape, appeared at first sight to be oil or mucilage cells; simple perforations in such cells are obviously more easily overlooked, and it was not until a special search was made that they were found to be by no means uncommon, and to occur in woods of several different families.

scholarly journals Inflow mapping method for numerical flow simulations of OCT-based patient-specific vessels using CFD

2017 ◽  
Vol 3 (2) ◽  
pp. 603-606
Author(s):  
Carolin Wüstenhagen ◽  
Finja Borowski ◽  
Michael Haude ◽  
Franz-Josef Neumann ◽  
Niels Grabow ◽  
...  
Keyword(s):  
Flow Field ◽  
Imaging Techniques ◽  
Flow Characteristics ◽  
Coronary Vessels ◽  
Mapping Method ◽  
Side Branch ◽  
Patient Specific ◽  
Vessel Segment ◽  
Data Set ◽  
2D Data

AbstractAlteration of the flow characteristics in coronary vessels is correlated with coronary heart disease (CHD). In particular, wall shear stress (WSS) appears to be a hemody-namic key factor in the genesis of CHD. Since computational fluid dynamics (CFD) is a well-known method for the inves-tigation of WSS, it may be a valuable tool for the prediction of CHD. Latest imaging techniques, such as optical coher-ence tomography (OCT) in conjunction with angiography deliver precise 2D data sets of patient-specific vessel geome-try, which can be used for CFD analysis. Current CFD stud-ies utilize patient-specific geometries, but are lacking well defined physiologic inflow conditions.In this study, we present an inflow mapping method for patient-specific arterial vessels, which is capable of consider-ing the influence of bifurcations located proximal of the OCT-data set. At first, the patient-specific vessel was recon-structed. For this purpose the OCT-based vessel cross sec-tions were arranged along an angiographic based vessel pathway. Secondly, we simulated the flow field in a generic bifurcation model by means of CFD. Thereafter the flow field of a side branch was extracted and transferred (mapped) to the inlet of the patient-specific vessel.To evaluate the influence of the physiological inlet the WSS distribution of the same patient-specific vessel was calculated using an axial-symmetric inflow condition. Analy-sis of the simulation data yielded deviations of the WSS distribution in the proximal vessel segment. A bifurcation, located upstream of the relevant vessel segment strongly affects the flow in the OCT-based vessel reconstruction and has a strong influence on the results of the numerical analy-sis. Therefore, it is important to implement not only the pa-tient-specific geometry, but also an inlet boundary condition adapted to the upstream velocity distribution reflecting the actual proximal flow situation of the vessel.

scholarly journals Efficacy and Safety of an Intracameral Combination of Two Mydriatics and an Anesthetic for Phacoemulsification in Complicated Patients

2018 ◽  
Vol 12 (1) ◽  
pp. 322-329
Author(s):  
Raffaele Nuzzi ◽  
Valentina Baratozzi ◽  
Maria Sole Polito ◽  
Federico Tridico
Keyword(s):  
Adverse Events ◽  
Control Group ◽  
Systemic Diseases ◽  
Efficacy And Safety ◽  
Ocular Diseases ◽  
Safety And Efficacy

Background: Advantages of intracameral mydriatics have been demonstrated in healthy patients, but safety and efficacy in complicated subjects remain to be assessed. Objective: The purpose of this study is to evaluate efficacy and safety of an intracameral combination of phenylephrine (0.31%), tropicamide (0.02%) and lidocaine (1%) (Mydrane®, Thea Inc.) in phacoemulsification surgery in subgroups of patients affected by different systemic and ocular diseases. Methods: 125 patients were recruited and compared with a control group of 39 patients. Both groups have been divided according to the presence/absence of ocular or systemic diseases. In course of surgery, grade of mydriasis and ocular analgesia have been evaluated by the surgeon. During follow-up, eventual adverse events have been monitored. Also, comfort reported by patients and surgeon has been investigated. Results: 99.2% of patients receiving the intracameral formulation achieved acceptable mydriasis (> 6 mm), maintained during capsulorhexis, phacoemulsification and IOL insertion without the need of additional mydriatics. No adverse events or sings of unsuccessful surgery were observed among treated patients. Conclusion: An intracameral mydriatic solution can be a safe and comfortable tool for inducing and maintaining intraoperative mydriasis and analgesia, even in complicated patients.

scholarly journals Prevalence of Coexisting Systemic and Ocular Diseases among Cataract Surgery Patients: A Study in a Teaching Hospital in North East Malaysia

2019 ◽  
pp. 1-8
Author(s):  
Sagili Chandrasekhara Reddy
Keyword(s):  
Quality Of Life ◽  
Cataract Surgery ◽  
Teaching Hospital ◽  
Medical Records ◽  
Systemic Disease ◽  
Systemic Diseases ◽  
Ocular Diseases ◽  
North East ◽  
East Malaysia

Aim: To determine the prevalence of coexisting systemic and ocular diseases among the cataract surgery patients in a teaching hospital in north east Malaysia. Method: in this retrospective study, the medical records of patients who were operated for cataract over a period of three years by a single surgeon in the teaching Hospital University Sains Malaysia were analyzed for the coexisting systemic and ocular diseases. Some patients were operated in both eyes. Results: Out of 218 patients who underwent cataract surgery, one or more systemic diseases were present in 113 patients (51.8%). The most common associated systemic disease was diabetes mellitus (24.3%), followed by hypertension (22.4%). A total of 324 eyes were operated in these patients. In addition to cataract, one or more ocular diseases were present in 129 eyes (39.8%). The most common ocular disease in cataract eyes was pterygium (9.8%), followed by diabetic retinopathy (9.5%).  Conclusion:  Ophthalmologist has to identify the coexisting systemic and ocular diseases present among cataract surgery patients. These diseases should be adequately controlled before surgery in order to avoid intraoperative and postoperative complications, and to achieve better quality of life for the patients.

scholarly journals Retinal Artery-Vein Classification via Topology Estimation

2015 ◽  
Vol 34 (12) ◽  
pp. 2518-2534 ◽  
Author(s):  
Rolando Estrada ◽  
Michael J. Allingham ◽  
Priyatham S. Mettu ◽  
Scott W. Cousins ◽  
Carlo Tomasi ◽  
...  
Keyword(s):  
Retinal Artery ◽  
Topology Estimation

Cardiac involvement in systemic diseases

2011 ◽  
Author(s):  
Andreas Hagendorff
Keyword(s):  
Cardiac Tissue ◽  
Cardiac Involvement ◽  
Imaging Techniques ◽  
Coronary Thrombosis ◽  
Systemic Disease ◽  
Diagnostic Technique ◽  
Invasive Procedure ◽  
Diagnostic Methods ◽  
Systemic Diseases ◽  
Cardiac Events

Systemic diseases are generally an interdisciplinary challenge in clinical practice. Systemic diseases are able to induce tissue damage in different organs with ongoing duration of the illness. The heart and the circulation are important targets in systemic diseases. The cardiac involvement in systemic diseases normally introduces a chronic process of alterations in cardiac tissue, which causes cardiac failure in the end stage of the diseases or causes dangerous and life-threatening problems by induced acute cardiac events, such as myocardial infarction due to coronary thrombosis. Thus, diagnostic methods—especially imaging techniques—are required, which can be used for screening as well as for the detection of early stages of the diseases. Two-dimensional echocardiography is the predominant diagnostic technique in cardiology for the detection of injuries in cardiac tissue—e.g. the myocardium, endocardium, and the pericardium—due to the overall availability of the non-invasive procedure.The quality of the echocardiography and the success rate of detecting cardiac pathologies in patients with primary non-cardiac problems depend on the competence and expertise of the investigator. Especially in this scenario clinical knowledge about the influence of the systemic disease on cardiac anatomy and physiology is essential for central diagnostic problem. Therefore the primary echocardiography in these patients should be performed by an experienced clinician or investigator. It is possible to detect changes of cardiac morphology and function at different stages of systemic diseases as well as complications of the systemic diseases by echocardiography.The different parts of this chapter will show proposals for qualified transthoracic echocardiography focusing on cardiac structures which are mainly involved in different systemic diseases.

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

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

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

Vitrectomy and Vitreoretinal Surgery in Persistent Macular Edema

2021 ◽  
pp. 341-349
Keyword(s):  
Diabetic Retinopathy ◽  
Macular Edema ◽  
Inflammatory Diseases ◽  
Treatment Options ◽  
Vitreoretinal Surgery ◽  
Posterior Segment ◽  
Systemic Diseases ◽  
Ocular Diseases ◽  
Vein Occlusion ◽  
Common Causes

Macular edema can occur as a result of many ocular diseases and systemic diseases. Edema is associated with vascular leaking conditions. Diabetic retinopathy, retinal vein occlusion, posterior segment inflammatory diseases, and intraocular surgery are the most common causes. There are many treatment options in the treatment of edema. Despite medical and laser treatment, there may be persistent cases. Some of these cases can benefit from vitrectomy and vitreoretinal surgery. This review will focus on the place and applications of vitrectomy and vitreoretinal surgery in persistent macular edema.

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