1. 1-24 of 24
    1. Contribution to Intra-Retinal Fluid Segmentation in Optical Coherence Tomography by Using Automatic Personalized Thresholding

      Contribution to Intra-Retinal Fluid Segmentation in Optical Coherence Tomography by Using Automatic Personalized Thresholding

      Background: Cystoid macular edema (CME) is associated to several ocular pathologies and is considered as a principal cause of severe central vision loss. Optical Coherence Tomography (OCT) allows the identification of fluid regions and the evaluation of disease severity and treatment efficiency. The quantification of fluid volume may be a useful metric in the diagnosis and the choice of treatment protocols. Methods: This work describes a fully automatic process for intra-retinal fluid segmentation. It identifies fluid regions in a retinal volume stack, then, fluid volume is quantified. The presented method includes three main steps; first we apply a denoising process ...

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    2. A Quantum Field Approach for Advancing Optical Coherence Tomography Part I: First Order Correlations, Single Photon Interference, and Quantum Noise

      A Quantum Field Approach for Advancing Optical Coherence Tomography Part I: First Order Correlations, Single Photon Interference, and Quantum Noise

      Optical coherence tomography has become an important imaging technology in cardiology and ophthalmology, with other applications under investigations. Major advances in optical coherence tomography (OCT) imaging are likely to occur through a quantum field approach to the technology. In this paper, which is the first part in a series on the topic, the quantum basis of OCT first order correlations is expressed in terms of full field quantization. Specifically first order correlations are treated as the linear sum of single photon interferences along indistinguishable paths. Photons and the electromagnetic (EM) field are described in terms of quantum harmonic oscillators. While ...

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    3. Peripapillary Vascular Changes in Nonarteritic Anterior Ischemic Optic Neuropathy by Optical Coherence Tomography Angiography: A Case Report | Open Access Journals

      Peripapillary Vascular Changes in Nonarteritic Anterior Ischemic Optic Neuropathy by Optical Coherence Tomography Angiography: A Case Report | Open Access Journals

      Background: To report the sequential peripapillary vascular changes in nonarteritic anterior ischemic optic neuropathy (NAION) with optical coherence tomography angiography (OCTA) Methods: A 60-year-old male presented with right eye painless vision loss leading to inferior field defects and right eye 0.5 vision. The sequential OCTA was performed at presentation and 5 months later to evaluate the peripapillary vascular changes. Results: At presentation, the OCTA revealed decreased peripapillary capillary perfusion in the area corresponding to the nerve fiber swelling, along with increased blood flow of the major retinal vessel. Five months later, the OCTA showed decreased blood flow in the ...

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    4. Automatic Segmentation of Posterior Pole Retinal Layers In Patients with Early Stage Glaucoma Using Spectral Domain Optical Coherence Tomography

      Automatic Segmentation of Posterior Pole Retinal Layers In Patients with Early Stage Glaucoma Using Spectral Domain Optical Coherence Tomography

      Purpose: To measure Ganglion Cell Layer (GCL) and Retinal Nerve Fiber Layer (RNFL) thickness of the retinal posterior pole in patients with early stage primary open-angle glaucoma (POAG) using the new automatic segmentation technology of spectral domain optical coherence tomograph (SD-OCT). Methods: 37 clinical records of patients with early glaucoma (grade 1 to 2 according to the Glaucoma Staging System 2) and 40 age and sex-matched controls were considered in this case-control observational retrospective study. Automated segmentation of GCL and RNFL was performed in one randomly selected eye from the electronic OCT records of each participant using the new Spectralis ...

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    5. The Evaluation of Choroidal Vascular Changes Associated with Vascular Dysregulation in Patients with Multiple Sclerosis Using Enhanced Depth Imaging Optical Coherence Tomography

      The Evaluation of Choroidal Vascular Changes Associated with Vascular Dysregulation in Patients with Multiple Sclerosis Using Enhanced Depth Imaging Optical Coherence Tomography

      Purpose: To evaluate the choroidal thickness (CT) in patients with Multiple Sclerosis (MS) using enhanced depth imaging optical coherence tomography (EDI-OCT) and comparing it with healthy subjects. Material/Methods: Sixty-four eyes of 32 patients with MS (22 women, 10 men, mean age: 37.5 ± 8.21 years) were enrolled in this study. Their choroidal thickness was measured using EDI-OCT, and compared with healthy subjects. CT was measured at fovea and at four extrafoveal points. Results: The mean subfoveal choroidal thickness was 327.01 ± 64.60 µm in MS patients and 365.3 ± 99.14 µm in controls ( p=0.019 ...

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    6. The Additional Diagnostic Value of Optical Coherence Tomography (OCT) and Its Application Procedure in A Wide Variety of Avian Species

      The Additional Diagnostic Value of Optical Coherence Tomography (OCT) and Its Application Procedure in A Wide Variety of Avian Species

      Objective : The current study introduced OCT as a novel tool in clinical veterinary ophthalmology in a much wider variety of free-living avian species than hitherto studied. Methods: OCT was tested and performed in 39 free-living birds (21 species of 12 families) and compared to direct ophthalmoscopy. Birds were examined with combinations of different restraints (manual restraint or fixation on a holding device) and different anaesthesia regimes (none, sedation, general anaesthesia). Inter- and intra-species specific variations of the general procedure, the restraint methods and the clinical findings were evaluated. Results: OCT was possible in all examined avian species (from 40 g ...

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    7. Comparing Structure-Function Correlations in Superior Segmental Optic Nerve Hypoplasia and Juvenile Open Angle Glaucoma Using Spectral-Domain Optical Coherence Tomography

      Comparing Structure-Function Correlations in Superior Segmental Optic Nerve Hypoplasia and Juvenile Open Angle Glaucoma Using Spectral-Domain Optical Coherence Tomography

      Superior segmental optic nerve hypoplasia (SSOH) is a congenital anomaly of the optic nerve that is commonly misdiagnosed as normal tension glaucoma (NTG) and/or juvenile open angle glaucoma (JOAG). We demonstrate the utility of SD-OCT in assessing the structure-function correlation when differentiating between SSOH and JOAG.

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    8. Doppler Optical Coherence Tomography Imaging of Feeder Vessels in Exudative Macular Disease

      Doppler Optical Coherence Tomography Imaging of Feeder Vessels in Exudative Macular Disease

      We evaluated the three-dimensional vascular architecture of feeder vessels in exudative macular disease. A case of polypoidal choroidal vasculopathy with choroidal neovascularization was examined with Doppler optical coherence tomography (OCT), and the three-dimensional architecture of the feeder vessels could be clearly visualized in the Doppler OCT angiography image, showing the site of growth of the feeder vessels passing through Bruch’s membrane. Together, the results demonstrated in this case report that Doppler OCT was useful for the noninvasive assessment of feeder vessels in exudative macular disease.

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    9. Pars Plana Vitrectomy with Air Tamponade for Optic Disc Pit Maculopathy: Swept-source Optical Coherence Tomography Imaging Findings and Surgical Approach

      Pars Plana Vitrectomy with Air Tamponade for Optic Disc Pit Maculopathy: Swept-source Optical Coherence Tomography Imaging Findings and Surgical Approach

      Purpose: To describe how Swept Source Optical Coherence Tomography (SS-OCT) provides enhanced diagnostic information enabling optimisation of surgical strategy in a pediatric patient suffering from ODP maculopathy. We report the first case of successful management of ODP maculopathy via pars plana vitrectomy (PPV) and air tamponade. Methods: Interventional case report. Results: A five-year-old girl presented with ODP and serous macular detachment in her previously amblyopic left eye. SS-OCT showed optically opaque vitreous fibres perpendicularly attached to the base of the optic nerve head excavation and what appeared to be fibrous tissue at the base of the excavation of the optic ...

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    10. Different Concentrations of Aqueous Cytokines According to Diabetic Macular Edema Patterns as Determined Optical Coherence Tomography

      Different Concentrations of Aqueous Cytokines According to Diabetic Macular Edema Patterns as Determined Optical Coherence Tomography

      Objective: To evaluate the relationship between various cytokine levels in aqueous humor and diabetic macular edema (DME) types as determined by optical coherence tomographic (OCT) patterns. Methods: The study examined 76 patients with DME at early phase. Ten patients who underwent cataract surgery served as controls. Eyes with DME were divided into four groups, based on OCT patterns of DME, prior to intravitreal bevacizumab injection (IVB). Patterns included sponge-like diffuse retinal thickening (SDRT) (n=27), cystoid macular edema (CME) (n=18), serous retinal detachment (SRD) (n=15), and combined CME and SRD (n=16). Visual acuity, central macular thickness (CMT ...

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    11. Assessment of Tear Meniscus with Optical Coherence Tomography in Patients with Type 2 Diabetes Mellitus

      Assessment of Tear Meniscus with Optical Coherence Tomography in Patients with Type 2 Diabetes Mellitus

      Objective: To analyze the tear- meniscus with Optical Coherence Tomography (OCT) in patients with type 2 diabetes mellitus. Methods: Patients with type 2 diabetes without Diabetic Retinopathy (DMR) (n=56), with non-proliferative DMR (NPDR) (n=40), proliferative DMR (PDR) (n=30) and control (n=50) were enrolled in the study. HbA1c and Early Treatment Diabetic Retinopathy Study classification of DMR were evaluated. To analyze dry eye, Schirmer test, Tear Break-Up Time (TBUT) test and fluorescein corneal staining were done. Tear Meniscus Height (TMH), Depth (TMD) and Area (TMA) were obtained with Fourier domain-OCT (FD-OCT). Results: TMH, TMD and TMA were ...

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    12. Transient OCT Highly Reflective Layer Following Macular Hole Surgery

      Transient OCT Highly Reflective Layer Following Macular Hole Surgery

      Objective: Internal Limiting Membrane (ILM) peeling during macular hole surgery is commonly performed. In spite of this, little is known about the exact histological effect that this has on the retina post-operatively, due to a lack of clinicopathological studies. OCT imaging is increasing our understanding of structural changes that occur after macular hole surgery, and is now widely used. Recently OCT observations have included Concentric Macular Dark Spots (CMDS) and Swelling of the Arcuate Nerve Fibre Layer (SANFL). In this paper a new postoperative OCT observation is described. This occurs transiently after macular hole surgery. The observation consists of a ...

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    13. Current OCT Approaches Do Not Reliably Identify TCFAs

      Current OCT Approaches Do Not Reliably Identify TCFAs

      It is now clearly established that Thin-Capped Fibroatheromas (TCFAs) lead to most Acute Coronary Syndromes (ACSs). The ability to selectively intervene on TCFAs predisposed to rupture and ACSs would dramatically alter the practice of cardiology. While the ability of OCT to identify thin walled plaques at micron scale resolutions has represented a major advance, it is a misconception that it can reliably identify TCFAs. One major reason is that the ‘diffuse border’ criteria currently used to determine ‘lipid plaque’ is almost undoubtedly from high scattering in the intima and not because of core composition (necrotic core). A second reason is ...

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    14. High-Definition Optical Coherence Tomography in the Diagnosis of Basal Cell Carcinoma Evaluated by an Experienced Versus Inexperienced Investigator

      High-Definition Optical Coherence Tomography in the Diagnosis of  Basal Cell Carcinoma Evaluated by an Experienced Versus Inexperienced  Investigator

      Background: Histopathology is the gold standard in the diagnosis of basal cell carcinoma (BCC) but biopsies are invasive and often not the preferred diagnostic method for patients. In this context, non-invasive diagnostic imaging tools such as high definition optical coherence tomography (HD-OCT) have shown promising results in diagnosing BCC in real time, atraumatically and repeatedly. Objective: To evaluate the sensitivity and specificity of HD-OCT in the diagnosis of BCC by an experienced versus an inexperienced investigator and describe typical features in common differential diagnosis of BCC. Patients and methods: Forty three patients with clinical suspicion for BCC were included. The ...

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    15. Detection of Retinal Changes in Patients on Long Term Chloroquine/Hydroxy Chloroquine Therapy Using Optical Coherence Tomography

      Detection of Retinal Changes in Patients on Long Term Chloroquine/Hydroxy Chloroquine Therapy Using Optical Coherence Tomography

      Background: The best technique to diagnose chloroquine/ hydroxychloroquine-induced retinopathy changes at the earliest remains ambiguous at present. In this study, we evaluated the time-domain optical coherence tomography (OCT) to identify retinal changes associated with chloroquine and hydroxychloroquine. Methods: One hundred patients with immunological diseases were included in the study. Fifty of them had been on chloroquine and/or hydroxychloroquine therapy for at least five years and the other 50 patients as controls. Detailed ophthalmic examination including Amsler grid , colour vision , automated threshold white perimetry using 10-2 protocol on Humphrey field analyzer, fluorescein angiography when indicated and time domain Optical Coherence ...

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    16. Engineering of Nanoscale Contrast Agents for Optical Coherence Tomography

      Engineering of Nanoscale Contrast Agents for Optical Coherence Tomography

      Optical coherence tomography has emerged as valuable imaging modality in ophthalmology and other fields by enabling high-resolution three-dimensional imaging of tissue. In this paper, we review recent progress in the field of contrast-enhanced optical coherence tomography (OCT). We discuss exogenous and endogenous sources of OCT contrast, focusing on their use with standard OCT systems as well as emerging OCT-based imaging modalities. We include advances in the processing of OCT data that generate improved tissue contrast, including spectroscopic OCT (SOCT), as well as work utilizing secondary light sources and/or detection mechanisms to create and detect enhanced contrast, including photothermal OCT ...

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    17. Using Optical Coherence Tomography (OCT) to Evaluate Human Donor Kidneys Prior to and Following Transplantation

      Using Optical Coherence Tomography (OCT) to Evaluate Human Donor Kidneys Prior to and Following Transplantation

      The most common insult to donor kidneys destined for transplantation is Acute Tubular Necrosis (ATN). The extent of ATN will affect post-transplant function and is a significant risk factor for long-term graft function and survival. Optical Coherence Tomography (OCT) is a rapidly emerging imaging modality that can function as a type of “optical biopsy”, providing non-invasive images of tissue morphology in situ and in real-time. In this paper, we review studies that support the use of OCT and Doppler based OCT (i.e., DOCT) to image the renal microstructure and blood flow of human donor kidneys. We conclude that OCT ...

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    18. A Bibliometric Analysis of Optic Coherence Tomography Studies in Multiple Sclerosis

      A Bibliometric Analysis of Optic Coherence Tomography Studies in  Multiple Sclerosis

      igh-resolution cross-sectional images of the retina that has been used for ten years in multiple sclerosis (MS) related optic neuropathies. The objective of this study is to determine the scientific output in use of OCT in multiple sclerosis between 1982 and 2012 using ISI Web of Knowledge. Methods: The ISI Web of Knowledge was searched for articles on OCT published between 1982 and February 2012 using appropriate terms. Articles were characterized each year by publication type. Results: Search yielded 154 publications after the search for keywords “optical coherence tomography and multiple sclerosis and 167 publications after the search for the ...

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    19. Optical Coherence Tomography in the Era of Drug-Eluting Stents: An Indispensable Workhorse

      Optical Coherence Tomography in the Era of Drug-Eluting Stents: An Indispensable Workhorse

      Undoubtedly, the breakthrough introduction of drug-eluting stents (DES) has nearly abolished the need for reintervention, accounting for nearly 10-15% need for target vessel revascularization (TVR) at longterm follow-up [1,2]. Indeed, the enthusiasm associated with the early results of first-generation DES let us believe that the long-standing concern inherent to percutaneous coronary intervention (PCI) has probably come to a pleasant end. After years ‘in duty’, however, worrisome reports have raised concerns about disturbingly high rates of late and very late (after one year) stent thrombosis associated with DES, that frequently culminates into myocardial infarction or, even more gravely, death [3 ...

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    20. Anterior Segment Optical Coherence Tomography in Glaucoma Diagnostics: is Fourier- or Time-domain more useful?

      Anterior Segment Optical Coherence Tomography in Glaucoma Diagnostics: is Fourier- or Time-domain more useful?

      Several new methods based on evolving technologies were introduced in the last decades to enhance and facilitate anterior segment diagnostics in glaucoma. Nowadays, in addition to conventional slit lamp biomicroscopy and gonioscopy, ultrasound biomicroscopy (UBM) and recently anterior segment optical coherence tomography (AS-OCT) are considered to be valuable and indispensable tools especially for patients with primary and secondary angle closure glaucomas.

      In the early 1990s the AS-OCT was introduced for cornea and glaucoma diagnosis [1]. In contrast to UBM, AS-OCT is a noncontact, high resolution imaging technique which is fast and optimal for noncompliant patients or even children [2] and ...

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    21. Imaging Lamina Cribrosa with Spectral Domain Ocular Coherence Tomography: An overview

      Imaging Lamina Cribrosa with Spectral Domain Ocular Coherence Tomography: An overview

      Glaucoma is characterized by optic nerve head cupping and visual field defects that could be detected with long-term rigorous monitoring of patients. There is not yet a good screening test for the disease, hence emphasis should be on prevention of progression of the disease by risk reduction. Currently, the only proven method to prevent the progressionglaucomatous disease is lowering the intraocular pressure (IOP). The precise mechanism by which IOP contributes to the development and progression of glaucoma is not completely understood [1,2]. This is, in part, due to the variability in individual susceptibility to IOP [3]. To better understand ...

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    22. Optical Coherence Tomography Analysis of Clinical and Subclinical

      Optical Coherence Tomography Analysis of Clinical and Subclinical

      Background: Coronary plaque ruptures occur not only in acute coronary syndrome (ACS) patients but also in non-ACS patients. There is a great interest in the reason why some plaque ruptures lead to ACS but others do not. We used optical coherence tomography (OCT) to identify anatomic features that lead to the development of culprit lesions causing ACS after plaque rupture.Methods: We assessed 102 plaque ruptures by using OCT and compared lesion morphologies betweensymptomatic plaque rupture in unstable angina pectoris (UAP; n=67) and silent plaque rupture in stable anginapectoris (SAP; n=35).Results: In the cross-sectional view, rupture was ...

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    23. Anterior Segment Optical Coherence Tomography in Glaucoma

      Anterior Segment Optical Coherence Tomography in Glaucoma
      Several new methods based on evolving technologies were introduced in the last decades to enhance and facilitate anterior segment diagnostics in glaucoma. Nowadays, in addition to conventional slit lamp biomicroscopy and gonioscopy, ultrasound biomicroscopy (UBM) and recently anterior segment optical coherence tomography (AS-OCT) are considered to be valuable and indispensable tools especially for patients with primary and secondary angle closure glaucomas. In the early 1990s the AS-OCT was introduced for cornea and glaucoma diagnosis [1]. In contrast to UBM, AS-OCT is a noncontact, high resolution imaging technique which is fast and optimal for noncompliant patients or even children [2] and ...
      Read Full Article
    1-24 of 24
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