1. Articles from Grace M. Richter

    1-14 of 14
    1. Repeatability and Reproducibility of 4.5 by 4.5 mm Peripapillary Optical Coherence Tomography Angiography Scans in Glaucoma and Nonglaucoma Eyes

      Repeatability and Reproducibility of 4.5 by 4.5 mm Peripapillary Optical Coherence Tomography Angiography Scans in Glaucoma and Nonglaucoma Eyes

      Prcis: Peripapillary vessel parameters from optical coherence tomography angiography (OCTA) 4.5×4.5 mm scans in nonglaucomatous and glaucomatous eyes showed high repeatability and reproducibility, with higher reliability for commercially developed OCTA parameters compared with custom OCTA parameters. Purpose: The purpose of this study was to assess intrasession repeatability versus intersession reproducibility of peripapillary vessel parameters from 4.5×4.5 mm OCTA scans in nonglaucomatous eyes and glaucomatous eyes. Materials and methods: In a longitudinal study, peripapillary OCTA scans were quantified using research-oriented custom quantification software that calculated vessel area density (VAD) and flux and clinic-oriented commercially developed ...

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    2. Wedge Defects on Optical Coherence Tomography Angiography of the Peripapillary Retina in Glaucoma

      Wedge Defects on Optical Coherence Tomography Angiography of the Peripapillary Retina in Glaucoma

      Precis: Among subjects with glaucoma, wedge-shaped defects on optical coherence tomography angiography were associated with disc hemorrhages, paracentral visual field defects, increased cup-to-disc ratio, and thinner retinal nerve fiber layer. Purpose: To examine determinants of wedge defects on peripapillary optical coherence tomography angiography (OCTA) in glaucoma. Methods: 278 eyes of 186 subjects with mild to severe primary open angle glaucoma (POAG) underwent 6×6 spectral domain-OCTA imaging of the superficial peripapillary retina from 2016-2020 at an academic practice. Wedge defects were defined as focal microvasculature loss that extends outward from the optic nerve in an arcuate, wedge shape. Logistic regression ...

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    3. Birefringent tissue-mimicking phantom for polarization-sensitive optical coherence tomography imaging

      Birefringent tissue-mimicking phantom for polarization-sensitive optical coherence tomography imaging

      Significance: Tissue birefringence is an important parameter to consider when designing realistic, tissue-mimicking phantoms. Options for suitable birefringent materials that can be used to accurately represent tissue scattering are limited. Aim: To introduce a method of fabricating birefringent tissue phantoms with a commonly used material-polydimethylsiloxane (PDMS)-for imaging with polarization-sensitive optical coherence tomography (PS-OCT). Approach: Stretch-induced birefringence was characterized in PDMS phantoms made with varying curing ratios, and the resulting phantom birefringence values were compared with those of biological tissues. Results: We showed that, with induced birefringence levels up to 2.1 × 10 - 4, PDMS can be used to resemble ...

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    4. Optimal number and orientation of anterior segment OCT images to measure ocular biometric parameters in angle closure eyes: the Chinese American Eye Study

      Optimal number and orientation of anterior segment OCT images to measure ocular biometric parameters in angle closure eyes: the Chinese American Eye Study

      Purpose: To assess the optimal number and orientation of anterior segment optical coherence tomography (AS-OCT) images for accurately measuring ocular biometric parameters in angle closure eyes. Methods: Subjects with angle closure, defined as >3 quadrants of non-visible pigmented trabecular meshwork on static gonioscopy, were selected from the Chinese American Eye Study. Mean angle opening distance (AOD500) was calculated using four images (0°-180°, 45°-225°, 90°-270° and 135°-315° meridians) from one eye per subject. Ten eyes from each quartile of AOD500 measurements were randomly selected for detailed 32-image analysis of 10 biometric parameters, including AOD500, iris curvature (IC ...

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    5. Steps to Measurement Floor of an Optical Microangiography Device in Glaucoma

      Steps to Measurement Floor of an Optical Microangiography Device in Glaucoma

      Purpose To compare dynamic ranges and steps to measurement floors of peripapillary and macular metrics from a complex signal-based optical microangiography (OMAG C ) optical coherence tomography angiography (OCTA) device for glaucoma with those of OCT measurements. Design Cross-sectional study. Methods Imaging of 252 eyes from 173 glaucoma subjects and 123 eyes from 92 non-glaucoma subjects from a glaucoma clinic was quantified using custom and commercial software. Metrics from OCT (retinal nerve fiber layer [RNFL], ganglion cell-inner plexiform layer [GCIPL]) and OCTA (custom: peripapillary vessel area density [pVAD], macular vessel area density [mVAD], macular vessel skeleton density [mVSD]; commercial: peripapillary perfusion ...

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    6. Advances in Ocular Imaging in Glaucoma (Textbook)

      Advances in Ocular Imaging in Glaucoma (Textbook)

      Serving as a practical guide to the ocular imaging modalities that are currently available to eye care providers for the care of glaucoma patients, this book provides information on advances in ocular imaging and their applications in the diagnosis and management of glaucoma. Each chapter introduces the imaging modality, highlight its strengths and weaknesses for clinical care, and discuss its integration into the clinical examination and decision-making process. The chapters also provide an in-depth description of the interpretation of images from each imaging modality. When appropriate, the chapters will summarize past and ongoing research and propose future research directions and ...

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    7. Effect of Scan Size on Glaucoma Diagnostic Performance Using OCT Angiography En Face Images of the Radial Peripapillary Capillaries

      Effect of Scan Size on Glaucoma Diagnostic Performance Using OCT Angiography En Face Images of the Radial Peripapillary Capillaries

      Precis: When comparing 4.5×4.5 mm to 6.0×6.0 mm optical coherence tomography angiography scans of the radial peripapillary capillaries (RPCs) for glaucoma diagnostic capability, there was a trend of 4.5 scans outperforming 6.0 scans, especially for inferior, nasal, and superior quadrants. Objectives: The main purpose of this study was to compare diagnostic ability of peripapillary vessel parameters from 4.5×4.5 mm (4.5) and 6.0×6.0 mm (6.0) spectral-domain optical coherence tomography angiography scans of the RPC in detecting primary open-angle glaucoma from nonglaucoma eyes. Methods: Consecutive patients ...

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    8. Quantitative Evaluation of Gonioscopic and EyeCam Assessments of Angle Dimensions Using Anterior Segment Optical Coherence Tomography

      Quantitative Evaluation of Gonioscopic and EyeCam Assessments of Angle Dimensions Using Anterior Segment Optical Coherence Tomography

      Purpose : To evaluate the relationship between angle dimensions assessed by gonioscopy or EyeCam and anterior segment optical coherence tomography (AS-OCT). Methods : Subjects aged 50 years or older were recruited from the Chinese American Eye Study (CHES). Each subject underwent a complete ocular exam, including gonioscopy, AS-OCT, and EyeCam. Angle closure was defined as three or more quadrants in which pigmented trabecular meshwork could not be visualized. Angle opening distance (AOD), angle recess area (ARA), trabecular iris space area (TISA), trabecular iris angle (TIA), and scleral spur angle (SSA) were measured in each AS-OCT image. Results : 709 eyes (272 angle closure ...

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      Mentions: UCLA
    9. Diagnostic Performance of Macular Versus Peripapillary Vessel Parameters by Optical Coherence Tomography Angiography for Glaucoma

      Diagnostic Performance of Macular Versus Peripapillary Vessel Parameters by Optical Coherence Tomography Angiography for Glaucoma

      Purpose : To compare the diagnostic ability of the vessel parameters in macular and peripapillary regions measured using spectral-domain optical coherence tomography angiography (SD-OCTA) in differentiating primary open-angle glaucoma (POAG) from healthy eyes. Methods : POAG patients and healthy subjects underwent 6 × 6-mm scans centered on the macula and optic nerve head. Commercially available automatic segmentation created en face images from SD-OCTA of the superficial retinal layer (SRL) of the macular (m) and peripapillary (cp) regions. Vessel area density (VAD), vessel skeleton density (VSD), vessel complexity index (VCI), and flux were calculated. Area under curve (AUC) statistics controlled for age and intereye ...

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    10. Peripapillary microvasculature in the retinal nerve fiber layer in glaucoma by optical coherence tomography angiography: focal structural and functional correlations and diagnostic performance

      Peripapillary microvasculature in the retinal nerve fiber layer in glaucoma by optical coherence tomography angiography: focal structural and functional correlations and diagnostic performance

      Purpose: To quantify peripapillary microvasculature within the retinal nerve fiber layer (RNFL) in primary open-angle glaucoma (POAG) and normal eyes, determine association of perfusion parameters with structural and functional measures, and report diagnostic accuracy of perfusion parameters. Patients and methods: POAG and normal patients underwent 6×6 mm2 optic nerve head scans (Angioplex optical coherence tomography angiography [OCTA]; Cirrus HD-OCT 5000) and Humphrey Field Analyzer II-i 24-2 visual field (VF) testing. Prototype software performed semiautomatic segmentation to create RNFL en face images and quantified vessel area density (VAD), vessel skeleton density (VSD), and vessel complexity index (VCI) in the optic ...

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    11. Structural and Functional Associations of Macular Microcirculation in the Ganglion Cell-inner Plexiform Layer in Glaucoma Using Optical Coherence Tomography Angiography

      Structural and Functional Associations of Macular Microcirculation in the Ganglion Cell-inner Plexiform Layer in Glaucoma Using Optical Coherence Tomography Angiography

      Purpose: To quantify retinal microvasculature within the macular ganglion cell-inner plexiform layer (GCIPL) in primary open angle glaucoma (POAG) and normal eyes, determine association of vessel parameters with structural and functional measures, and report diagnostic accuracy of vessel parameters. Methods: POAG and normal patients underwent 6▒mm×6▒mm macula scans (Angioplex TM optical coherence tomography angiography [OCTA]; Cirrus TM HD-OCT 5000); and Humphrey Field Analyzer II-i 24-2 visual field (VF) (Zeiss, Dublin, CA). Prototype software performed semi-automatic segmentation to create GCIPL en face images, and quantified vessel area density (VAD), vessel skeleton density (VSD), and vessel complexity index (VCI ...

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    12. The Promise of Optical Coherence Tomography Angiography in Glaucoma

      The Promise of Optical Coherence Tomography Angiography in Glaucoma

      Optical coherence tomography angiography (OCTA) studies in primary open-angle glaucoma have consistently demonstrated reduced microcirculation in the superficial optic nerve, 1 peripapillary retina, 2 , 3 and the macula 4 , 5 of glaucoma patients. These studies clearly demonstrate the superior resolution of OCTA compared with prior methods that were used to measure ocular blood flow (OBF) or its surrogates. How will OCTA help the glaucoma clinician now and in the future? What else must we learn before achieving more practical usefulness from OCTA for glaucoma? First, OCTA will supplement current glaucoma diagnostic tools to aid in the early detection of glaucoma ...

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    13. Optical coherence tomography angiography: A comprehensive review of current methods and clinical applications

      Optical coherence tomography angiography: A comprehensive review of current methods and clinical applications

      OCT has revolutionized the practice of ophthalmology over the past 10–20 years. Advances in OCT technology have allowed for the creation of novel OCT-based methods. OCT-Angiography (OCTA) is one such method that has rapidly gained clinical acceptance since it was approved by the FDA in late 2016. OCTA images are based on the variable backscattering of light from the vascular and neurosensory tissue in the retina. Since the intensity and phase of backscattered light from retinal tissue varies based on the intrinsic movement of the tissue (e.g. red blood cells are moving, but neurosensory tissue is static), OCTA ...

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    14. Regression Analysis of Optical Coherence Tomography Disc Variables for Glaucoma Diagnosis

      Regression Analysis of Optical Coherence Tomography Disc Variables for Glaucoma Diagnosis

      Purpose: To report diagnostic accuracy of optical coherence tomography (OCT) disc variables using both time-domain (TD) and Fourier-domain (FD) OCT, and to improve the use of OCT disc variable measurements for glaucoma diagnosis through regression analyses that adjust for optic disc size and axial length-based magnification error. Design: Observational, cross-sectional. Participants: In total, 180 normal eyes of 112 participants and 180 eyes of 138 participants with perimetric glaucoma from the Advanced Imaging for Glaucoma Study. Methods: Diagnostic variables evaluated from TD-OCT and FD-OCT were: disc area, rim area, rim volume, optic nerve head volume, vertical cup-to-disc ratio (CDR), and horizontal ...

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    1-14 of 14
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    Regression Analysis of Optical Coherence Tomography Disc Variables for Glaucoma Diagnosis Optical coherence tomography angiography: A comprehensive review of current methods and clinical applications The Promise of Optical Coherence Tomography Angiography in Glaucoma Structural and Functional Associations of Macular Microcirculation in the Ganglion Cell-inner Plexiform Layer in Glaucoma Using Optical Coherence Tomography Angiography Peripapillary microvasculature in the retinal nerve fiber layer in glaucoma by optical coherence tomography angiography: focal structural and functional correlations and diagnostic performance Diagnostic Performance of Macular Versus Peripapillary Vessel Parameters by Optical Coherence Tomography Angiography for Glaucoma Quantitative Evaluation of Gonioscopic and EyeCam Assessments of Angle Dimensions Using Anterior Segment Optical Coherence Tomography Effect of Scan Size on Glaucoma Diagnostic Performance Using OCT Angiography En Face Images of the Radial Peripapillary Capillaries Advances in Ocular Imaging in Glaucoma (Textbook) Steps to Measurement Floor of an Optical Microangiography Device in Glaucoma Editorial – Optical Coherence Tomography Angiography: Considerations Regarding Diagnostic Parameters Imaging of the optic nerve: technological advances and future prospects