Harvard University

Using Ultrawide Field-Directed Optical Coherence Tomography for Differentiating Nonproliferative and Proliferative Diabetic Retinopathy

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Purpose: To evaluate the ability of ultrawide field (UWF)–directed optical coherence tomography (OCT) to detect retinal neovascularization in eyes thought to have severe nonproliferative diabetic retinopathy (NPDR). Methods: Retrospective study of 20 consecutive patients diagnosed with severe NPDR by clinical examination. All patients underwent UWF color imaging (UWF-CI) and UWF-directed OCT following a prespecified imaging protocol to assess the mid periphery, 15/32 (46.9%) eyes underwent UWF–fluorescein angiography (FA). On OCT, new vessels elsewhere (NVE) were defined when vessels breached the internal limiting membrane. Results: A total of 32 eyes of 20 patients were evaluated. Of the 45 suspected areas of intraretinal microvascular abnormalities (IRMA) on UWF-CI, 38 (84.4%) were imaged by UWF-directed OCT, and 9/38 IRMA (23.7%) were NVE by OCT. Furthermore, UWF-directed OCT identified seven additional NVE in three eyes not seen on UWF-CI. This resulted in a change in diabet...

Ultrahigh resolution optical coherence tomography markers of normal aging and early age-related macular degeneration

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Purpose Ultrahigh resolution spectral domain optical coherence tomography (UHR SD-OCT) enables in vivo visualization of micrometric structural markers which differentially associate with normal aging versus age-related macular degeneration (AMD). This study explores the hypothesis that UHR SD-OCT can detect and quantify sub-retinal pigment epithelium (RPE) deposits in early AMD, separating AMD pathology from normal aging. Design Prospective cross-sectional study. Participants 53 non-exudative (dry) AMD eyes from 39 patients, and 63 normal eyes from 39 subjects. Methods Clinical UHR SD-OCT scans were performed using a high-density protocol. Exemplary high-resolution histology and transmission electron microscopy (TEM) images were obtained from archive donor eyes. Three trained readers evaluated and labeled outer retina morphological features, including the appearance of a hypo-reflective split within the RPE – RPE basal lamina (RPE-BL) – Bruch’s membrane (BrM) complex on UHR B...

Prevalence of venous loops and association with retinal ischemia in diabetic retinopathy using widefield swept-source OCT angiography

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Purpose To investigate the prevalence and clinical characteristics of diabetic patients with retinal venous loops (RVLs) and to assess the association with retinal ischemia using widefield swept-source optical coherence tomography angiography (WF SS-OCTA). Methods In this retrospective, cross-sectional study, a total of 195 eyes of 132 diabetic patients (31 eyes with no diabetic retinopathy (DR), 76 eyes with nonproliferative DR (NPDR), and 88 eyes with proliferative DR (PDR)) were imaged with WF SS-OCTA using Angio 6 × 6 mm and Montage 15 × 15 mm scans. Quantitative ischemia-related parameters, including ischemia index (ratio of nonperfusion area to total retinal area), foveal avascular zone (FAZ), and neovascularization features, were evaluated. RVLs were classified as type I or type II according to the branching level of the feeder vessel. A multivariate generalized estimating equations (GEE) logistic regression model was used to analyze the association of systemic parameter...

Automatic intraluminal scanning with a steerable endoscopic optical coherence tomography catheter for gastroenterology applications

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Significance Endoscopic optical coherence tomography (OCT) enables real-time optical biopsy of human organs. Endoscopic probes require miniaturization of optics, which in turn limits field of view. When larger imaging areas are needed such as in the gastrointestinal tract, the operator must manually scan the probe over the tissue to extend the field of view, often resulting in an imperfect scanning pattern and increased risk of missing lesions. Automatic scanning has the potential to extend the field of view of OCT, allowing the user to focus on image interpretation during real-time observations. Aim This work proposes an automatic scanning using a steerable OCT catheter integrated with a robotized interventional flexible endoscope. The aim is to extend the field of view of a low-profile OCT probe while improving scanning accuracy and maintaining a stable endoscope’s position during minimally invasive treatment of colorectal lesions. Approach A geometrical model of the steerabl...

Artificial intelligence in glaucoma: posterior segment optical coherence tomography

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Purpose of Review To summarize the recent literature on deep learning (DL) model applications in glaucoma detection and surveillance using posterior segment optical coherence tomography (OCT) imaging. Recent Findings DL models use OCT derived parameters including retinal nerve fiber layer (RNFL) scans, macular scans, and optic nerve head (ONH) scans, as well as a combination of these parameters, to achieve high diagnostic accuracy in detecting glaucomatous optic neuropathy (GON). Although RNFL segmentation is the most widely used OCT parameter for glaucoma detection by ophthalmologists, newer DL models most commonly use a combination of parameters, which provide a more comprehensive approach. Compared to DL models for diagnosing glaucoma, DL models predicting glaucoma progression are less commonly studied but have also been developed. Summary DL models offer time-efficient, objective, and potential options in the management of glaucoma. Although artificial intelligence mode...

Facilitating glaucoma diagnosis with inter-eye neuroretinal rim asymmetry analysis using spectral domain optical coherence tomography

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Purpose: To determine if inter-eye asymmetry of a three-dimensional neuroretinal rim parameter, the minimum distance band, is useful in differentiating normal from open-angle glaucoma eyes. Materials and Methods: This is a cross-sectional study. Both eyes of 28 normal subjects 33 glaucoma subjects were analyzed. Subjects underwent spectral domain optical coherence tomography imaging of both eyes. A custom-designed segmentation algorithm calculated mean minimum distance band neuroretinal rim thickness globally, for four quadrants and for four sectors. Inter-eye minimum distance band thickness asymmetry was calculated as the absolute difference in minimum distance band thickness values between the right and left eyes. Results:  Increasing minimum distance band thickness asymmetry was not associated with increasing age or increasing refractive error asymmetry. Glaucoma patients had thinner mean neuroretinal rim thickness values compared to normal patients (209.0 μm versus 306.0 μ...

Improving efficiency and operator proficiency during percutaneous coronary interventions utilizing a standardized optical coherence tomography workflow

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Objectives This study was designed to compare efficiency and quality metrics between percutaneous coronary intervention (PCI) procedures using optical coherence tomography (OCT) guided by a variable workflow versus a standardized workflow in a real-world population. Background The LightLab (LL) Initiative was designed to evaluate the impact of a standardized OCT workflow during PCI to address barriers to adoption. Methods The LL Initiative was a multicenter, prospective, observational study. PCI efficiency data were collected from 1/21/19 to 1/8/21 from 45 physicians at 17 US centers. OCT-guided PCIs were compared between baseline phase (variable workflow; N = 383) and the LL workflow utilization phase (N = 447). The LL workflow uses OCT to assess lesion Morphology, Length and Diameter, and then optimize outcomes by correcting for Medial dissection, stent mal-Apposition, and under-eXpansion (MLD MAX). Matching based on propensity scores was used to control for differences betwe...

OCT utilization: Summary statistics from the LightLab clinical initiative

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Objectives The study describes the evolution of optical coherence tomography (OCT) adoption and performance during percutaneous coronary intervention (PCI) following implementation of a standardized LightLab (LL) workflow. Background The purpose of the LL Clinical Initiative was to evaluate the impact of a standardized workflow on physician efficiency, decision making, and image quality. Methods The LL Clinical Initiative is a multicenter, prospective, observational clinical program. Data were collected from 48 physicians at 17 U.S. centers from 01/21/19 to 06/08/21. The study included 401 OCT-guided PCIs during the baseline phase and 1898 during the LL workflow phases. The baseline phase consisted of physicians utilizing OCT at their discretion. After completing the baseline phase, the workflow progressed through multiple phases culminating in the expansion phase, which focused on addressing greater procedural complexity. The LL workflow utilized OCT to assess plaque Morpholog...

Post-Doctoral Fellow (Translational Biomedical Optics) at Massachusetts General Hospital / Harvard Medical School

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Division of Pulmonary and Critical Care Medicine / Department of Pathology Employer: Massachusetts General Hospital / Harvard Medical School The Hariri Optical Imaging Laboratory is a multidisciplinary research group at Massachusetts General Hospital and Harvard Medical School. The focus of the laboratory is on the design, development and clinical translation of endoscopic optical coherence tomography (OCT)-based imaging devices for microscopic detection, diagnosis and monitoring of pulmonary diseases, including lung fibrosis, smoking and vaping-related lung diseases, post-COVID lung disease and interstitial lung abnormalities. A highly motivated, independent, innovative, and organized individual with an interest in translational optical/diagnostic imaging and biomedicine is sought for a Post-Doctoral Research Fellow position. The appropriate candidate will work in a highly collaborative multidisciplinary research environment consisting of engineers, physicians and technici...

Wide-Field Three-Dimensional Depth-Invariant Cellular-Resolution Imaging of the Human Retina

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Three-dimensional (3D) cellular-resolution imaging of the living human retina over a large field of view will bring a great impact in clinical ophthalmology, potentially finding new biomarkers for early diagnosis and improving the pathophysiological understanding of ocular diseases. While hardware-based and computational adaptive optics (AO) optical coherence tomography (OCT) have been developed to achieve cellular-resolution retinal imaging, these approaches support limited 3D imaging fields, and their high cost and intrinsic hardware complexity limit their practical utility. Here, this work demonstrates 3D depth-invariant cellular-resolution imaging of the living human retina over a 3 × 3 mm field of view using the first intrinsically phase-stable multi-MHz retinal swept-source OCT and novel computational defocus and aberration correction methods. Single-acquisition imaging of photoreceptor cells, retinal nerve fiber layer, and retinal capillaries is presented across unprecedented...

Postdoctoral Research Fellowships (In Vivo Microscopy) at Massachusetts General Hospital

Employer Description Guillermo (Gary) J. Tearney, M.D., Ph.D. Tearney Lab – Wellman Center for Photomedicine Massachusetts General Hospital The Tearney Lab is an 80+ person multidisciplinary lab led by Guillermo (Gary) Tearney, MD, PhD. The goal of the Tearney Lab is to see every cell in the human body so that disease can be detected at its earliest stages when it can be cured.  To this end, the lab has pioneered multiple optical coherence tomography (OCT) devices that enable 3D imaging at the microscopic scale in living human patients. These technologies include multimodality OCT where OCT is combined with spectroscopy, fluorescence, and other optical techniques, ultrahigh-resolution OCT (µOCT) where the resolution is sufficiently detailed to visualize individual cells, and functional OCT that measures the function and metabolism of cells in living systems. These technologies are implemented in a variety of devices (endoscopes, catheters, capsules, implan...

Postdoctoral Research Fellowships (OCT Image Processing and Machine Learning) at Massachusetts General Hospital

Employer Description Guillermo (Gary) J. Tearney, M.D., Ph.D. Tearney Lab – Wellman Center for Photomedicine Massachusetts General Hospital  The Tearney Lab is an 80+ person multidisciplinary lab led by Guillermo (Gary) Tearney, MD, PhD. The goal of the Tearney Lab is to see every cell in the human body so that disease can be detected at its earliest stages when it can be cured.  To this end, the lab has pioneered multiple optical coherence tomography (OCT) devices that enable 3D imaging at the microscopic scale in living human patients. These technologies include multimodality OCT where OCT is combined with spectroscopy, fluorescence, and other optical techniques, ultrahigh-resolution OCT (µOCT) where the resolution is sufficiently detailed to visualize individual cells, and functional OCT that measures the function and metabolism of cells in living systems. These technologies are implemented in a variety of devices (endoscopes, catheters, capsules, ...

Postdoctoral Research Fellowships (Optical Coherence Tomography) at Massachusetts General Hospital

Employer Description Guillermo (Gary) J. Tearney, M.D., Ph.D. Tearney Lab – Wellman Center for Photomedicine Massachusetts General Hospital  The Tearney Lab is an 80+ person multidisciplinary lab led by Guillermo (Gary) Tearney, MD, PhD. The goal of the Tearney Lab is to see every cell in the human body so that disease can be detected at its earliest stages when it can be cured.  To this end, the lab has pioneered multiple optical coherence tomography (OCT) devices that enable 3D imaging at the microscopic scale in living human patients. These technologies include multimodality OCT where OCT is combined with spectroscopy, fluorescence, and other optical techniques, ultrahigh-resolution OCT (µOCT) where the resolution is sufficiently detailed to visualize individual cells, and functional OCT that measures the function and metabolism of cells in living systems. These technologies are implemented in a variety of devices (endoscopes, catheters, capsules, ...

Data Scientist Opening in Optical Coherence Tomography at Massachusetts General Hospital

Employer Description Guillermo (Gary) J. Tearney, M.D., Ph.D. Tearney Lab – Wellman Center for Photomedicine Massachusetts General Hospital  The Tearney Lab is an 80+ person multidisciplinary lab led by Guillermo (Gary) Tearney, MD, PhD. The goal of the Tearney Lab is to see every cell in the human body so that disease can be detected at its earliest stages when it can be cured.  To this end, the lab has pioneered multiple optical coherence tomography (OCT) devices that enable 3D imaging at the microscopic scale in living human patients. These technologies include multimodality OCT where OCT is combined with spectroscopy, fluorescence, and other optical techniques, ultrahigh-resolution OCT (µOCT) where the resolution is sufficiently detailed to visualize individual cells, and functional OCT that measures the function and metabolism of cells in living systems. These technologies are implemented in a variety of devices (endoscopes, catheters, capsules, ...

Intracoronary Imaging of Vulnerable Plaque—From Clinical Research to Everyday Practice

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The introduction into clinical practice of intravascular imaging, including intravascular ultrasound (IVUS), optical coherence tomography (OCT) and their derivatives, allowed for the in vivo assessment of coronary atherosclerosis in humans, including insights into plaque evolution and progression process. Intravascular ultrasound, the most commonly used intravascular modality in many countries, due to its low resolution cannot assess many features of vulnerable plaque such as lipid plaque or thin-cap fibroatheroma. Thus, novel methods were introduced to facilitate this problem including virtual histology intravascular ultrasound and later on near-infrared spectroscopy and OCT. Howbeit, none of the currently used modalities can assess all known characteristics of plaque vulnerability; hence, the idea of combining different intravascular imaging methods has emerged including NIRS-IVUS or OCT-IVUS imaging. All of those described methods may allow us to identify the most vulnerable plaq...

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