1. Articles in category: Ophthalmology

    49-72 of 11376 « 1 2 3 4 5 6 ... 472 473 474 »
    1. Optical Coherence Tomography of the Retina in Schizophrenia: Relationships with Visual and Perceptual Function (Thesis)

      Optical Coherence Tomography of the Retina in Schizophrenia: Relationships with Visual and Perceptual Function (Thesis)

      Background: Visual perceptual impairments are well established in schizophrenia, ranging from deficits in basic visual discrimination to abnormalities in higher-level visual integration. Recent research has identified thinning o f retinal layers in individuals with schizophrenia, which may contribute to visual dysfunction. This study utilized optical coherence tomography to examine retinal integrity in individuals with schizophrenia, and investigated the contributions of retinal structure to low- and higher-level visual functions in schizophrenia. Methods: Participants were 12. individuals with schizophrenia-spectrum disorders and 12 age-matched healthy controls. Optical coherence tomography was utilized to obtain measurements for the retinal nerve fiber layer (RNFL), ganglion cell ...

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    2. Ocular Morphological Changes in Patients with Restless Legs Syndrome Analyzed by Optical Coherence Tomography

      Ocular Morphological Changes in Patients with Restless Legs Syndrome Analyzed by Optical Coherence Tomography

      Background Two leading hypotheses for restless legs syndrome (RLS) pathophysiology are dopaminergic dysfunction and sympathetic overactivity. Ocular changes occur with both dopaminergic and sympathetic pathologies, and thus may provide unique insights into the pathophysiology of RLS. Methods Thirty-five patients with RLS and 35 healthy individuals were enrolled in the study. Peripapillary retinal nerve fiber layer (RNFL), macular, and choroidal thicknesses were measured by optical coherence tomography (OCT). Results There were no statistically significant differences between the two groups regarding RNFL and macular thicknesses. The subfoveal, temporal and nasal choroidal thicknesses were significantly thinner in patients with RLS compared with normal ...

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      Mentions: Emory University
    3. Scanning optical coherence tomography probe for in vivo imaging and displacement measurements in the cochlea

      Scanning optical coherence tomography probe for in vivo imaging and displacement measurements in the cochlea

      We developed a spectral domain optical coherence tomography (SDOCT) fiber optic probe for imaging and sub-nanometer displacement measurements inside the mammalian cochlea. The probe, 140 μm in diameter, can scan laterally up to 400 μm by means of a piezoelectric bender. Two different sampling rates are used, 10 kHz for high-resolution B-scan imaging, and 100 kHz for displacement measurements in order to span the auditory frequency range of gerbil (~50 kHz). Once the cochlear structures are recognized, the scanning range is gradually decreased and ultimately stopped with the probe pointing at the selected angle to measure the simultaneous displacements of ...

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    4. OPTICAL COHERENCE TOMOGRAPHY LEAKAGE IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION

      OPTICAL COHERENCE TOMOGRAPHY LEAKAGE IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION

      Purpose: To test optical coherence tomography leakage in the identification and quantification of choroidal neovascularization–related fluid, its change after anti–vascular endothelial growth factor therapy in neovascular age-related macular degeneration eyes and its relation to functional outcome. Methods: Prospective analysis of a cohort of neovascular age-related macular degeneration cases treated with 2.0-mg intravitreal aflibercept. Eyes included were analyzed before, 1-week, and 1-month after one injection. Best-corrected visual acuity was assessed using Early Treatment Diabetic Retinopathy Study method. Optical coherence tomography leakage maps depicting low optical reflectivity (LOR) sites were acquired with OCT Cirrus AngioPlex (Zeiss, Dublin, CA). The ...

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    5. Optical Coherence Tomography-based Diagnostic Criteria for Different Stages of Myopic Maculopathy

      Optical Coherence Tomography-based Diagnostic Criteria for Different Stages of Myopic Maculopathy

      Purpose To analyze the choroidal thickness (CT) of each type of myopic maculopathy, and to establish an OCT-based classification of myopic maculopathy. Design Retrospective, hospital-based, cross-sectional study. Participants Highly myopic (HM) eyes that were examined by swept-source OCT. Methods The CT was measured at the subfovea and at 3 mm nasal, temporal, superior, and inferior to the fovea. Myopic maculopathy was classified as tessellation, diffuse atrophy, patchy atrophy, and macular atrophy (MA) based on the fundus photographs. Diffuse atrophy was subdivided into peripapillary diffuse choroidal atrophy (PDCA) or macular diffuse choroidal atrophy (MDCA). Main Outcome Measures The CT of each ...

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    6. Cellular resolution corneal imaging with extended imaging range

      Cellular resolution corneal imaging with extended imaging range

      Current optical coherence tomography (OCT) technology, which is used for imaging the eye’s anterior segment, has been established as a clinical gold standard for the diagnosis of corneal diseases. However, the cellular resolution level information that is critical for many clinical applications is still not available. The major technical challenges toward cellular resolution OCT imaging are the limited ranging depth and depth of focus (DOF). In this work, we present a novel ultrahigh resolution OCT system that achieves an isotropic spatial resolution of <2 µm in tissue. The proposed system could approximately double the ranging depth and extend the ...

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    7. Intraoperative Optical Coherence Tomography to Guide Corneal Biopsy: A Case Report

      Intraoperative Optical Coherence Tomography to Guide Corneal Biopsy: A Case Report

      Purpose: To report on a new application of intraoperative optical coherence tomography (OCT) as a real-time imaging tool to help guide corneal biopsy . Methods: Single case report. After the negative result of a corneal biopsy , we used intraoperative OCT during repeat biopsy to assist in depth and acquisition of an anterior stromal opacity suspected to be immunoglobulin deposits. Results: The use of intraoperative OCT is a novel tool, which assisted in successful identification and conservative biopsy of corneal immunoglobulin deposits. Conclusions: Intraoperative OCT is a novel tool that assists in the identification and location of corneal pathology for biopsy.

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    8. OCT-A Can Distinguish Papilledema from Its Mimickers

      OCT-A Can Distinguish Papilledema from Its Mimickers

      True swelling of the optic nerve head (papilledema) is an urgent, life-threatening condition. Pseudopapilledema, on the other hand, is a mostly benign buildup of optic nerve drusen. Telling them apart can be tricky, and doctors rarely have the luxury of time to do so. Papilledema can indicate an underlying brain tumor, obstructive hydrocephalus or meningitis. Over the years, doctors have hunted for small distinctions—such as the presence of Paton’s Lines, flame-shaped hemorrhages or cotton wool spots, but while these aren’t present in pseudopapilledema, they’re not 100% guaranteed to be present in papilledema either. 1 According to ...

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    9. Reproducibility of Dual Beam Doppler Fourier-domain Optical Coherence Tomography in Healthy Subjects

      Reproducibility of Dual Beam Doppler Fourier-domain Optical Coherence Tomography in Healthy Subjects

      Dual beam Doppler Fourier-domain Optical coherence tomography (DOCT) is a noninvasive technique to quantify total retinal blood flow. To enable further development of this technique it is essential to assess short- and long-term reproducibility of DOCT blood flow measurements. In the present study, total retinal blood flow will be measured with DOCT at multiple time points to gain information of short- and long-term reproducibility. In addition, provocation with flickering light will be performed, which is known to lead to vasodilatation and an increase in retinal blood flow in healthy subjects. Vessel diameters will also be measured using the Dynamic Vessel ...

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    10. Probing dynamic processes in the eye at multiple spatial and temporal scales with multimodal full field OCT

      Probing dynamic processes in the eye at multiple spatial and temporal scales with multimodal full field OCT

      We describe recent technological progress in multimodal en face full-field optical coherence tomography that has allowed detection of slow and fast dynamic processes in the eye. We show that by combining static, dynamic and fluorescence contrasts we can achieve label-free high-resolution imaging of the retina and anterior eye with temporal resolution from milliseconds to several hours, allowing us to probe biological activity at subcellular scales inside 3D bulk tissue. Our setups combine high lateral resolution over a large field of view with acquisition at several hundreds of frames per second which make it a promising tool for clinical applications and ...

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    11. CHOROIDAL VASCULARITY INDEX QUANTIFICATION IN GEOGRAPHIC ATROPHY USING BINARIZATION OF ENHANCED-DEPTH IMAGING OPTICAL COHERENCE TOMOGRAPHIC SCANS

      CHOROIDAL VASCULARITY INDEX QUANTIFICATION IN GEOGRAPHIC ATROPHY USING BINARIZATION OF ENHANCED-DEPTH IMAGING OPTICAL COHERENCE TOMOGRAPHIC SCANS

      Purpose: To evaluate choroidal structural changes occurring over time in geographic atrophy (GA) secondary to age-related macular degeneration using choroidal vascularity index (CVI). Methods: Enhanced-depth imaging optical coherence tomography scans of 34 patients with GA and 32 control subjects were retrospectively analyzed. Data were collected at baseline and after a mean follow-up of 18.3 ± 8.3 months. Choroidal images were binarized using the ImageJ software, and the luminal area and stromal area were segmented. Choroidal vascularity index was defined as the ratio of luminal area to total choroid area. Results: Patients with GA showed significantly lower values of CVI ...

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    12. Accuracy of swept-source optical coherence tomography based biometry for intraocular lens power calculation: a retrospective cross–sectional study

      Accuracy of swept-source optical coherence tomography based biometry for intraocular lens power calculation: a retrospective cross–sectional study

      Background To evaluate the accuracy of biometric measurements by a swept-source optical coherence tomography (SS–OCT) based biometry for intraocular lens (IOL) power calculation. Methods This retrospective observational study enrolled 431 patients undergoing cataract surgery. The charts were reviewed to investigate the failure rate of axial length (AL) measurement of the SS–OCT biometer, partial coherence interferometry (PCI), and A–scan ultrasonography (US) according to cataract type and severity. AL and keratometry in 164 eyes with the same IOL inserted were measured using the SS–OCT biometer, PCI, and A–scan US. The SRK/T formula was used to calculate ...

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    13. Despeckling Algorithms for Optical Coherence Tomography Images: A Review (Book Chapter)

      Despeckling Algorithms for Optical Coherence Tomography Images: A Review (Book Chapter)

      Optical coherence tomography (OCT) is a non-invasive imaging technique widely used in ophthalmology. The presence of speckle affects the quality of OCT images. Despeckling is necessary to improve its visual quality, and it is an integral part of software packages used for the computerized analysis of OCT. Even though a few methods for despeckling OCT are available in the literature, a cross-comparison of their performance is not known to be available. In this chapter, the techniques available in the literature for despeckling the OCT images have been identified. The results of the despeckling algorithms are compared both qualitatively and quantitatively ...

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    14. New method to analyze sagittal images of upper eyelid obtained by anterior segment optical coherence tomography

      New method to analyze sagittal images of upper eyelid obtained by anterior segment optical coherence tomography

      Purpose : To report a new method to analyze sagittal images of the upper eyelid by anterior segment optical coherence tomography (AS-OCT). Methods : Ninety subjects equally divided into young (20–39 years), middle age (40–59 years), and elderly (60–79 years) group were studied. A sagittal image of the upper eyelid was obtained by AS-OCT (CASIA2, Tomey, Japan) and the following parameters were determined: upper eyelid thickness (UET), the distance between two parallel lines tangential to the apexes of the cornea and the upper eyelid; the upper eyelid angle (UEA) was the angle formed by a line running tangential to ...

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    15. CORRELATION OF EN FACE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY AVERAGING VERSUS SINGLE-IMAGE QUANTITATIVE MEASUREMENTS WITH RETINAL VEIN OCCLUSION VISUAL OUTCOMES

      CORRELATION OF EN FACE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY AVERAGING VERSUS SINGLE-IMAGE QUANTITATIVE MEASUREMENTS WITH RETINAL VEIN OCCLUSION VISUAL OUTCOMES

      Purpose: To demonstrate the effect of averaging multiple en face optical coherence tomography angiography images on the correlation between retinal microvasculature quantitative metrics and best-corrected visual acuity (BCVA) in eyes with retinal vein occlusion . Methods: A cross-sectional cohort with unilateral retinal vein occlusion was imaged in both eyes. Five 3 mm × 3-mm spectral domain optical coherence tomography angiography images were averaged, and quantitative parameters from averaged versus single images were correlated with logMAR BCVA. Regression analyses were performed to correlate quantitative metrics with BCVA. Results: Ten patients (5 male, average age 64.3 years) were included. Among retinal vein occlusion ...

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    16. Quantity and quality of image artifacts in optical coherence tomography angiography

      Quantity and quality of image artifacts in optical coherence tomography angiography

      Objective To analyze quality and frequency of OCTA artifacts and to evaluate their impact on the interpretability of OCTA images. Design 75 patients with diabetic retinopathy (DR), retinal artery occlusion (RAO), retinal vein occlusion (RVO), or neovascular age-related macular degeneration (nAMD) and healthy controls were enrolled in this cross-sectional study in the outpatient department of a tertiary eye care center. Methods All participants underwent an OCTA examination (spectral domain OCT Cirrus 5000 equipped with the AngioPlex module). OCTA scans were analyzed independently by two experienced ophthalmologists. Frequency of various artifacts for the entire OCTA scan and for different segmentation layers ...

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    17. Biomarkers of optical coherence tomography in evaluating the treatment outcomes of neovascular age-related macular degeneration: a real-world study

      Biomarkers of optical coherence tomography in evaluating the treatment outcomes of neovascular age-related macular degeneration: a real-world study

      This study evaluated the characteristic changes in optical coherence tomography (OCT) biomarkers in neovascular age-related macular degeneration (nAMD) treated with anti-vascular endothelial growth factor drugs and their relationship with visual outcomes at 1-year follow-up in a real-world setting. We retrospectively reviewed the medical records of 126 eyes with nAMD treated with either intravitreal ranibizumab or aflibercept, including ophthalmologic examinations and spectral-domain OCT at baseline and months 3, 6, and 12 after first injection. Treatment response of intraretinal cysts (IRCs), subretinal fluid (SRF), and pigment epithelial detachment (PED), and the correlation between best-corrected visual acuity (BCVA) changes and these OCT biomarkers ...

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    18. Characterizing Branching Vascular Network Morphology in Polypoidal Choroidal Vasculopathy by Optical Coherence Tomography Angiography

      Characterizing Branching Vascular Network Morphology in Polypoidal Choroidal Vasculopathy by Optical Coherence Tomography Angiography

      This study analyze the morphological characteristics of branching vascular networks (BVN) in polypoidal choroidal vasculopathy (PCV) using optical coherence tomography angiography (OCTA), and correlate imaging characteristics with clinical presentations. We presented a retrospective observational case series for fifty cases of PCV confirmed by indocyanine green angiography. Macular OCTA were done by the AngioVue. The PCV cases were classified by distinct morphologic patterns of BVN by two retina specialists and clinical features were analyzed. The sensitivity of polyp detection by OCTA was 86% after manual segmentation and that of BVN was 90%. Three distinct morphologic patterns of BVN were identified. (1 ...

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    19. Optical coherence tomography is highly sensitive in detecting prior optic neuritis

      Optical coherence tomography is highly sensitive in detecting prior optic neuritis

      Objective To explore sensitivity of optical coherence tomography (OCT) in detecting prior unilateral optic neuritis. Methods This is a retrospective, observational clinical study of all patients who presented from January 1, 2014, to January 6, 2017, with unilateral optic neuritis and OCT available at least 3 months after the attack. We compared OCT retinal nerve fiber layer (RNFL) and ganglion cell inner plexiform layer (GCIPL) thicknesses between affected and unaffected contralateral eyes. We excluded patients with concomitant glaucoma or other optic neuropathies. Based on analysis of normal controls, thinning was considered significant if RNFL was at least 9 µm or ...

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      Mentions: Randy H. Kardon
    20. University of Miami Receives NIH Grant for Endothelium/Deschmet's Membrane Complex Optical Tomography

      University of Miami Receives NIH Grant for Endothelium/Deschmet's Membrane Complex Optical Tomography

      University of Miami Receives a 2019 NIH Grant for $219,654 for Endothelium/Deschmet's Membrane Complex Optical Tomography. The principal investigator is Abou Shousha. The program began in 2016 and ends in 2020. Below is a summary of the proposed work. More than 50% of corneal transplants, the most common form of solid organ transplantation, are performed to restore vision lost secondary to corneal endothelial failure. More than 25% of those transplants will eventually fail and endothelial cell rejection leading to failure is the single most important cause. The key to protec the endothelium is the early and accurate ...

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    21. Semi-Supervised Automatic Segmentation of Layer and Fluid Region in Retinal Optical Coherence Tomography Images Using Adversarial Learning

      Semi-Supervised Automatic Segmentation of Layer and Fluid Region in Retinal Optical Coherence Tomography Images Using Adversarial Learning

      Optical coherence tomography (OCT) is a primary imaging technique for ophthalmic diagnosis due to its advantages in high resolution and non-invasiveness. Diabetes is a chronic disease, which could cause retinal layer deformation and fluid accumulation. It might increase the risk of blindness, and thus, it is important to monitor the morphology change of the retinal layer and fluid accumulation for diabetes patients. Due to the existence of deformation and fluid accumulation, the retinal layer and fluid region segmentation in the OCT image is a challenging task. Machine learning-based segmentation methods have been proposed, but they depend on a significant number ...

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    22. Effect of contact lenses on ocular biometric measurements based on swept-source optical coherence tomography

      Effect of contact lenses on ocular biometric measurements based on swept-source optical coherence tomography

      Purpose: To determine the reliability of sweptsource optical coherence tomography in cases in which soft contact lenses cannot be removed when acquiring biometric measurements. Methods: Eight subjects were included and only one eye per participant was analyzed. Each eye was measured six times by swept-source optical coherence tomography with the IOLMaster 700 instrument (Carl Zeiss Meditec, Jena, Germany). Axial length, central corneal thickness, anterior chamber depth, lens thickness, and keratometric measurements were evaluated for the naked eye and while wearing soft contact lenses of three different powers (-1.5, -3.0, and +2.0 D). Results: There were statistically significant ...

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    23. Anterior segment optical coherence tomography (AS‐OCT) as a new method of detecting copper deposits forming the Kayser–Fleischer ring in patients with Wilson disease

      Anterior segment optical coherence tomography (AS‐OCT) as a new method of detecting copper deposits forming the Kayser–Fleischer ring in patients with Wilson disease

      Purpose Kayser–Fleischer ring pathognomonic for Wilson disease (WD) is formed of corneal copper deposits present predominantly within the anterior chamber angle at the Schwalbe's line. The slit‐lamp assessment commonly used as a standard of care cannot detect them early enough, as the angle view is obscured by the corneal limbus. The aim of the research was to evaluate the anterior segment optical coherence tomography (AS‐OCT), as objective diagnostic assessment of copper deposits forming KF ring in patients with WD. Methods Twenty‐nine subjects (17 women) and twenty‐nine controls (14 women) were enrolled and underwent slit ...

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    49-72 of 11376 « 1 2 3 4 5 6 ... 472 473 474 »
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