Glaucoma has become a major cause of vision loss. Early-stage diagnosis of glaucoma is critical for treatment planning to avoid irreversible vision damage. Meanwhile, interpreting the rapidly accumulated medical data from ophthalmic exams is cumbersome and resource-intensive. Therefore, automated methods are highly desired to assist ophthalmologists in achieving fast and accurate glaucoma diagnosis. Deep learning has achieved great successes in diagnosing glaucoma by analyzing data from different kinds of tests, such as peripapillary optical coherence tomography (OCT) and visual field (VF) testing. Nevertheless, applying these developed models to clinical practice is still challenging because of various limiting factors. OCT models ...

Objective: To evaluate retinal pigment epithelium (RPE) changes in Parkinson's Disease (PD) and to compare choroidal thickness (CT) and retinal layers with healthy controls. Methods: Parkinson's patients older than 18 and the age-sex match control group were included in this prospective observational study. The neurological and ophthalmological evaluation was performed. All participants were examined by spectral-domain optical coherence tomography. Focal RPE changes were defined as local RPE changes observed in any macula scan. Results: Forty (24 male, mean age 69.2 years) participants were included in the study group, and 44 (24 male, mean age 68.9 years ...

Topic: To evaluate the prognostic association between preoperative features seen on optical coherence tomography (OCT) imaging and postoperative visual acuity (VA) outcomes in rhegmatogenous retinal detachments (RRD). Clinical relevance: Currently, there is limited literature on the prognostic value of preoperative RRD OCT features. Methods: A literature search was conducted on Ovid MEDLINE, EMBASE and Cochrane CENTRAL from inception through September 15, 2022. A meta-analysis was performed using a random-effects model. Quality of studies and evidence was assessed using the JBI tools and GRADE framework, respectively. Results: A total of 1,671 eyes of 1,670 patients from 29 observational studies ...

Despite the contemporary techniques and devices available for invasive cardiology procedures, the current diagnostic, and interventional modalities have many shortcomings. As a contemporary cross-disciplinary technique, nanotechnology has demonstrated great potential in interventional cardiology practice. It has a pivotal role in detecting sensitive cardiac biomarkers, nanoparticle-enhanced gadolinium (Gd) contrast to enhance the detection of atherosclerotic cardiovascular disease (ASCVD), and multimodal imaging like including optical coherence tomography (OCT)/infrared luminescence (IR) for coronary plaque characterization. Furthermore, in invasive cardiology, the potential benefit is in miniaturized cardiac implantable electronic devices (CIEDs), including leadless pacemakers and piezoelectric nanogenerators to self-power symbiotic cardiac devices. Nanoparticles ...

Supervised deep learning has achieved prominent success in various diabetic macular edema (DME) recognition tasks from optical coherence tomography (OCT) volumetric images. A common problematic issue that frequently occurs in this field is the shortage of labeled data due to the expensive fine-grained annotations, which increases substantial difficulty in accurate analysis by supervised learning. The morphological changes in the retina caused by DME might be distributed sparsely in B-scan images of the OCT volume, and OCT data is often coarsely labeled at the volume level. Hence, the DME identification task can be formulated as a multiple instance classification problem that ...

Polarization sensitive optical coherence tomography (PSOCT) has been shown to image and delineate white matter fibers in a label-free manner by revealing optical birefringence within the myelin sheath using a microscope setup. In this proof-of-concept study, we adapt recent advancements in endoscopic PSOCT to perform depth-resolved imaging of white matter structures deep inside intact porcine brain tissue ex-vivo, through a small, rotational fiber probe. The probe geometry is comparable to microelectrodes currently used in neurosurgical interventions. The presented imaging system is mobile, robust, and uses biologically safe levels of optical radiation making it well suited for clinical translation. In neurosurgery ...

Despite the rapid development of optical imaging methods, high-resolution in vivo imaging with penetration into deeper tissue layers is still a major challenge. Optical coherence tomography (OCT) has been used successfully for non-invasive human retinal volumetric imaging in vivo, advancing the detection, diagnosis, and monitoring of various retinal diseases. However, there are important limitations of volumetric OCT imaging, especially coherent noise and the limited axial range over which high resolution images can be acquired. The limited range prevents simultaneous measurement of the retina and choroid with adequate lateral resolution. In this article, we address these limitations with a technique that ...

Case report

Introduction Levels of lipoprotein (LP) (a) are useful marker for risk stratification of cardiovascular disease. This genetic biomarker is suggestive of patient predisposition to acute coronary event. The present study was to study correlation of LP(a) levels and plaque morphology in very young patients (<35 years) with acute coronary syndrome (ACS). Methods A prospective, single-center, observational study consisting of very young patients with ACS and fit for optical coherence tomography (OCT) guided invasive coronary angiography was conducted at tertiary-care centre. LP(a) levels were compared between healthy controls and very young ACS patients. Correlation of LP(a) levels and ...

Background: Artificial intelligence enables simultaneous evaluation of plaque morphology and computational physiology from optical coherence tomography (OCT). Objectives: This study sought to appraise the predictive value of major adverse cardiovascular events (MACE) by combined plaque morphology and computational physiology. Methods: A total of 604 patients with acute coronary syndrome who underwent OCT imaging in ≥1 nonculprit vessel during index coronary angiography were retrospectively enrolled. A novel morphologic index, named the lipid-to-cap ratio (LCR), and a functional parameter to evaluate the physiologic significance of coronary stenosis from OCT, namely, the optical flow ratio (OFR), were calculated from OCT, together with classical ...

The Henle fiber layer (HFL) is comprised of bundles of unmyelinated photoreceptor axons intermingled with outer Müller cell processes. The photoreceptor axons extend from the cell bodies located in the outer nuclear layer and radially project toward the outer plexiform layer, the inner third of which includes the synaptic junctional complexes and the outer two-thirds of which includes the HFL. The oblique path of the HFL provides unique structural and reflectance properties and this radial anatomy is highlighted in many macular disorders including those with macular star exudation and HFL hemorrhage. Recent investigations using multimodal imaging techniques, especially cross ...

Optical coherence tomopgraphy angiography is an useful tool in detecting changes in retinal and choroidal perfusion in patients with idiopathic full thickness macular holes. • Systemic diseases like diabetes mellitus and hypertension can be confounding factors and can skew the results. Patients with such systemic diseases should not be included in the study. • Optical coherence tomography angiography study of the retinal and choroidal parameters should be repeated following successful surgical closure of the macular holes. This will lend more credibility to the hypothesis proposed.

No established biomarkers currently exist for therapeutic efficacy and durability of anti–VEGF therapy in neovascular age-related macular degeneration (nAMD). This study evaluated radiomic-based quantitative OCT biomarkers that may be predictive of anti-VEGF treatment response and durability. Design Assessment of baseline biomarkers using machine learning (ML) classifiers to predict tolerance to anti-VEGF therapy. Participants Eighty-one participants with treatment-naïve nAMD from the OSPREY study, including 15 super responders (patients who achieved and maintained retinal fluid resolution) and 66 non–super responders (patients who did not achieve or maintain retinal fluid resolution). Methods A total of 962 texture-based radiomic features were ...

To describe the normative quantitative parameters of the macular retinal vasculature as well as their systemic and ocular associations using OCT angiography (OCTA). Design Population-based, cross-sectional study. Subjects Adults aged > 50 years were recruited from the third examination of the population-based Singapore Malay Eye Study. Methods All participants underwent a standardized comprehensive examination and spectral-domain OCTA (Optovue) of the macula. OCT angiography scans that revealed pre-existing retinal disease, revealed macular pathology , and had poor quality were excluded. Main Outcome Measures The normative quantitative vessel densities of the superficial layer, deep layer, and foveal avascular zone (FAZ) were evaluated. Ocular and ...

Zebrafish as vertebrate model has applications in the fields of embryology, oncology, toxicology, molecular genetics and drug discovery due to its high homology with the human genome. The zebrafish embryogenesis presents a propitious model for concurrent visualization of developmental stages in vivo owing to transparency and ex-utero development of the embryo. Developments in imaging tools and techniques focus on providing real-time quantitative imaging. The present work demonstrates depth-resolved imaging of developing zebrafish using swept-source optical coherence tomography (SSOCT). The SSOCT system provides an axial resolution of 4.5 µm and an imaging depth of 3.26 mm. The paper also ...

Background The afferent visual pathway provides a unique opportunity to monitor clinical and subclinical optic neuritis and features of neuroaxonal degeneration in secondary progressive MS. Objective To investigate the usefulness of visual evoked potentials (VEP) and optical coherence tomography (OCT) in evaluating SPMS, and the association between these modalities and clinical course and lesion load on the magnetic resonance imaging (MRI) in patients with SPMS with or without a history of optic neuritis (ON). Methods SPMS patients (n=27) underwent clinical assessment with Expanded Disability Status Scale (EDSS) grading, visual acuity, OCT, and VEP examination. MRI of the brain and ...

Counterfeiting of banknotes is still a severe crime problem in many countries. One of the most significant issue for solving the crime is to classify the counterfeit types and identify the sources. Most of the current methods to classify counterfeit banknotes rely on manual examination that is time-consuming and labor-intensive. Moreover, these methods only detect surface features which can be easily imitated through advanced printing technology. In this study, an automated method based on optical coherence tomography (OCT) and machine-learning algorithms was proposed to classify different types of banknotes based on the internal features. A spectral-domain OCT (SD-OCT) system was ...

As an emerging tomographic technique, optical coherence tomography (OCT) has been widely used in clinical practice in a short period of time. Unfortunately, the quality of OCT images is inevitably deteriorated by the coherent noise known as speckle noise. To effectively reduce the speckle noise in OCT images while preserving local structures, we present a speckle noise reduction method based on feature-guided higher-order singular value decomposition (HOSVD). Specifically, the grouped 3D tensors are first decomposed by HOSVD. And then, the corresponding core tensors are thresholded according to the Eckart-Young-Mirsky theorem and are shrunk by the dectected edge features, which are ...

In the past decade, significant progress has been made in ceramics additive manufacturing (AM). Material research and the rapid evolution of high-resolution printing technologies enabled the production of high-quality, high-precision, complex/structured ceramic objects. In this contribution, we propose a contactless, non-destructive method of mid-infrared optical coherence tomography (mid-IR OCT) for at-line inspection and quality control of AM ceramics. The OCT system operates in the spectral range from 3.15 μm to 4.2 μm featuring extended probing depth into porous ceramics. The spatial resolution of the mid-IR OCT system is suited to most of AM techniques: the axial resolution ...

Optical Coherence Tomography (OCT) is a non-invasive method which can obtain high-definition images of cross section (B-scan) of the retina. By investigating the thickness of different layers of the retina in OCT images, one can diagnose ocular diseases in an early stage. Different algorithms have been proposed for retinal layer segmentation including machine learning techniques and various advanced CNN architectures, which have been developed recently. In this research, segmentation of OCT images is carried out for 9 boundaries, equivalent to segmenting eight retinal layers. We investigate different U-net like structures which can be combined with VGG and ResNet architectures to ...

En face optical coherence tomography (EF-OCT) is a rapid, non-invasive, high-resolution imaging technique that has evolved in recent years to be a routine examination for the assessment and follow-up of various vitreoretinal diseases. With the introduction of swept-source OCT (SS-OCT), which can achieve up to 100,000 A-scans per second and better-quality imaging of deeper structures using a longer wavelength (1050nm), EF-OCT reconstruction can produce high-resolution frontal images of the retina and choroid (C-Scans) that give an overview of disease extent. These images allow a more accurate study of vitreoretinal interface pathologies such as epiretinal membranes, macular holes, and vitreomacular ...

Background Acute coronary syndromes caused by plaque erosion might be potentially managed conservatively without stenting. Currently, the diagnosis of plaque erosion requires expertise in optical coherence tomographic (OCT) image interpretation. In addition, the current deep learning (DL) approaches for OCT image interpretation are based on a single frame, without integrating the information from adjacent frames. Objectives The aim of this study was to develop a novel DL model to facilitate an accurate diagnosis of plaque erosion. Methods A novel “Transformer”-based DL model was developed that integrates information from adjacent frames emulating the cardiologists who review consecutive OCT frames to ...

Background: To analyze the quantitative changes in both macular, and choroidal thickness, and microvascularization after panretinal photocoagulation (PRP) in eyes with proliferative diabetic retinopathy (PDR) or severe non-proliferative diabetic retinopathy (NPDR) by using optical coherence tomography angiography (OCT-A). Methods: The patients diagnosed with severe NPDR or PDR according to the Early Treatment Diabetic Retinopathy Study (ETDRS) and decided to be treated with PRP were included in this prospective and observational study. Ten eyes of 10 patients with PDR and twelve eyes of 12 patients with severe NPDR were examined. Macular scans (6 × 6 mm) were obtained from OCT-A at baseline ...

Purpose: To perform a longitudinal analysis of the effect of optic coherence tomography (OCT) biomarkers on macular thickness in patients with persistent macular edema secondary to diabetes mellitus and retinal vein occlusion who recieved intravitreal dexamethasone (DEX) implant. Methods: Eighty-nine patients were included in the retrospective study. Patients with anti-VEGF-resistant macular edema were included in the study. The effect of the presence or absence of OCT biomarkers before intravitreal DEX implant therapy on central foveal thickness (CFT) was evaluated. In addition, the change in biomarkers from the baseline visit to the final visit was evaluated. The evaluated OCT biomarkers were ...