1. Articles in category: Ophthalmology

    577-600 of 5623 « 1 2 ... 22 23 24 25 26 27 28 ... 233 234 235 »
    1. Retinal silicone oil emulsification found with SD-OCT

      Retinal silicone oil emulsification found with SD-OCT

      According to recent data small hyperreflective areas found intraretinally, subretinally and underneath the epiretinal membranes with spectral domain optical coherence tomography (SD-OCT) could be small bubbles of emulsified silicone. In this study, the authors (Dr Marie-Hélène Errera et al. , Moorfields Eye Hospital, London, UK, and Centre Hospitalier National des Quinze-Vingts, Paris, France) performed a retrospective case study on 11 eyes of 11 patients. Patients who had undergone vitrectomy and silicone oil tamponade whose SD-OCT imaging had shown silicone oil emulsion manifestations were identified. Out of these 11 patients, 9 had undergone treatment as a result of rhegmatogenous retinal ...

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    2. Quantitative analysis of retinal layers' optical intensities on 3D optical coherence tomography

      Quantitative analysis of retinal layers' optical intensities on 3D optical coherence tomography

      Purpose: To investigate the optical intensities of all retinal layers on 3D spectral domain optical coherence tomography (SD-OCT) in normal subjects using an automatic measurement. Methods: Forty normal subjects underwent Topcon 3D-OCT 1000 macula-centered scan. The raw data was automatically segmented into 10 layers using the 3D graph search approach. Then the mean and standard deviation of intensities of each layer were calculated. The image quality index was given by the OCT software. Correlation analysis was performed between the optical intensities in each layer with the image quality and subject's age. Results: The correlation of optical intensities was strong ...

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    3. In Vivo Three-Dimensional Corneal Epithelium Imaging in Normal Eyes by Anterior-Segment Optical Coherence Tomography: A Clinical Reference Study

      In Vivo Three-Dimensional Corneal Epithelium Imaging in Normal Eyes by Anterior-Segment Optical Coherence Tomography: A Clinical Reference Study

      Purpose: To evaluate the safety and efficacy of real-time measurement of corneal epithelial thickness and investigate the distribution characteristics in a large normal-eye population using a clinically available spectral-domain anterior-segment optical coherence tomography (AS OCT) system. Methods: Corneal epithelial thickness distribution and topographic thickness variability were clinically investigated using AS OCT imaging in 373 patients with normal, healthy eyes. Descriptive statistics investigated 3 sets of subgroups, male (n = 171) and female (n = 202), younger (n = 194) and older (n = 179), right eyes (n = 195) and left eyes (n = 197). Results: Pupil center epithelial thickness repeatability was an average 0.88 ...

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    4. Retina-simulating phantom for optical coherence tomography

      Retina-simulating phantom for optical coherence tomography

      Optical coherence tomography (OCT) is a rapidly growing imaging modality, particularly in the field of ophthalmology. Accurate early diagnosis of diseases requires consistent and validated imaging performance. In contrast to more well-established medical imaging modalities, no standardized test methods currently exist for OCT quality assurance. We developed a retinal phantom which mimics the thickness and near-infrared optical properties of each anatomical retinal layer as well as the surface topography of the foveal pit. The fabrication process involves layer-by-layer spin coating of nanoparticle-embedded silicone films followed by laser micro-etching to modify the surface topography. The thickness of each layer and dimensions ...

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    5. Evaluation of the Retina of Subjects Without Diabetes Mellitus and Subjects With Diabetes Mellitus Without Diabetic Retinopathy Using Optical Coherence Tomography

      Evaluation of the Retina of Subjects Without Diabetes Mellitus and Subjects With Diabetes Mellitus Without Diabetic Retinopathy Using Optical Coherence Tomography

      The purpose of this study is to evaluate topographic features of the posterior pole of the eye in normal subjects as well as in subjects with diabetes mellitus but without diabetic retinopathy (DR) usingoptical coherence tomography (OCT). The investigators proposal is a novel study to determine retinal volume of normal and diabetic subjects without DR. Specifically, the investigators will establish a standardized reference range for retinal thickness and volume that will provide standards for OCT analysis of different clinical trials for retinal diseases.

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    6. Optical coherence tomography findings in spinocerebellar ataxia-3

      Optical coherence tomography findings in spinocerebellar ataxia-3

      Purpose To report optical coherence tomography (OCT) findings in order to detect subclinical alterations of the afferent visual pathways in spinocerebellar ataxia 3 (SCA-3). Patients and methods Nine genetically confirmed patients (18 eyes) were evaluated with a complete ophthalmologic examination including visual acuity, colour vision, visual field test, and retinal nerve fibre layer (RNFL) and macular thickness with OCT Cirrus HD. A neurological examination was performed and the Scale for the Assessment and Rating of Ataxia (SARA score) was determined in all patients. Results The mean RNFL thickness was 77.39 microns, standard deviation (SD) was ±5.93. In 15 ...

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    7. Calibration of histological retina specimens after fixation in Margo’s solution and paraffin embedding to in-vivo dimensions, using photography and optical coherence tomography

      Calibration of histological retina specimens after fixation in Margo’s solution and paraffin embedding to in-vivo dimensions, using photography and optical coherence tomography

      Background The extent of retinal tissue deformation by histological processing needs to be separately measured for every workup protocol. This work presents a simple approach for its quantitative assessment, and shows lateral and axial scaling factors for a common protocol. We calibrated histological measurements by in-vivo photographic and optical coherence tomographic (OCT) measurements, using retinal photocoagulation lesions as calibration markers. Methods We evaluated four rabbit eyes that were examined histologically after fixation in Margo’s solution (1 % paraformaldehyde:1.25 % glutaraldehyde), isopropanol dehydration, paraffin embedding and hematoxylin and eosin staining. Distances between 51 pairs of laser lesions were compared in ...

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    8. Optical coherence reflectometry with depth resolution

      Optical coherence reflectometry with depth resolution

      A device for performing distance measurements on an eye. The device includes an interferometer, focuses at least one measurement beam records backscattered radiation and interferometrically generates a measurement signal displaying structures of the eye by time-domain, spectral-domain or Fourier-domain coherence reflectometry, has an adjustment apparatus for laterally and/or axially displacing the focus in the eye or for varying a polarization state of the measurement beam and has a control apparatus which actuates the interferometer, wherein the control apparatus generates a plurality of A-scan individual signals from the backscattered radiation, combines these to an A-scan measurement signal and actuates the ...

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    9. Feature Of The Week 9/15/13: Longitudinal Fundus and Retinal Studies with SD-OCT: A Comparison of Five Mouse Inbred Strains

      Feature Of The Week 9/15/13: Longitudinal Fundus and Retinal Studies with SD-OCT: A Comparison of Five Mouse Inbred Strains

      The mouse is a well established model for studying hereditary disorders, which have an effect on eye structure and function, including frequently occurring degenerative retinal diseases, such as retinitis pigmentosa. However, many of these retinal disorders remain to be characterized functionally to understand the underlying mechanisms and develop strategies for therapeutic intervention. Recently, a commercial third-generation SD-OCT system (Spectralis OCT, Heidelberg Engineering, Heidelberg, Germany) was adapted for high-resolution in vivo imaging of the mouse fundus and retinal morphology. This system has successfully been implemented into the first-line phenotyping of the German Mouse Clinic I (GMC I; www.mouseclinic.de) as ...

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    10. Changes in Optical Coherence Tomography Findings in Acute Zonal Occult Outer Retinopathy

      Changes in Optical Coherence Tomography Findings in Acute Zonal Occult Outer Retinopathy

      Purpose: To report a case of acute zonal occult outer retinopathy (AZOOR) in a 39-year-old woman. Methods: Images were obtained with fundus photography and optical coherence tomography (OCT). A multifocal electroretinogram (mfERG) was also obtained to evaluate retinal function. Results: The patient's right visual acuity was 0.8. Fundus photographs showed no specific abnormal findings. OCT showed attenuation of the photoreceptor inner segment/outer segment (IS/OS) line and the cone outer segment tip (COST) line in the right eye. The mfERG showed corresponding amplitude reductions. One month after the initial visit, her right visual acuity improved to 1 ...

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    11. Pulsatile motion of the trabecular meshwork in healthy human subjects quantified by phase-sensitive optical coherence tomography

      Pulsatile motion of the trabecular meshwork in healthy human subjects quantified by phase-sensitive optical coherence tomography

      Aqueous leaves the anterior chamber of eye by passing through the trabecular meshwork (TM), a tissue thought to be responsible for increased outflow resistance in glaucoma. Motion assessment could permit characterization of TM biomechanical properties necessary to maintain intra-ocular pressure (IOP) within a narrow homeostatic range. In this paper, we report the first in vivo identification of TM motion in humans. We use a phase-sensitive optical coherence tomography (PhS-OCT) system with sub-nanometer sensitivity to detect and image dynamic pulse-induced TM motion. To permit quantification of TM motion and relationships we develop and apply a phase compensation algorithm permitting removal of ...

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    12. Assessing the effects of ketorolac and acetazolamide on macular thickness by optical coherence tomography following cataract surgery

      Assessing the effects of ketorolac and acetazolamide on macular thickness by optical coherence tomography following cataract surgery

      We aimed to evaluate the efficacy of topical ketorolac 0.5 % solution and oral acetazolamide 250 mg/day delivery during the first month after uneventful phacoemulsification surgery by measuring the macular thickness using optical coherence tomography. Our nonmasked randomized prospective study comprised 87 eyes of 80 patients. Complete follow-up was achieved on 84 eyes of 77 eligible patients. Postoperatively, the patients were divided into three groups. One group received ketorolac 0.5 %, the other group received acetazolamide 250 mg/day, and the control group was given no agent. Macular thickness and volume were measured at 1 week and 1 month ...

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    13. New method for evaluation of early phase tear clearance by anterior segment optical coherence tomography

      New method for evaluation of early phase tear clearance by anterior segment optical coherence tomography

      Purpose To describe a new method of measuring early phase tear clearance by anterior segment optical coherence tomography (AS-OCT). Methods Sixty normal subjects were divided into a young group (30 subjects; 29.6 ± 7.2 years) and an elder group (30 subjects; 71.4 ± 10.8 years). AS-OCT (CASIA SS-1000, Tomey, Japan) with customized software was used to record the tear meniscus at the centre of the lower eyelid. Five microlitres of lukewarm saline solution was dropped into the lower conjunctival sac, and an image of the tear meniscus was obtained immediately and again 30 seconds after natural blinking. The ...

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    14. Branch retinal vein occlusion and vitreovascular traction: a preliminary spectral domain OCT case-control study

      Branch retinal vein occlusion and vitreovascular traction: a preliminary spectral domain OCT case-control study

      Objective Branch retinal vein occlusion (BRVO) typically occurs at an arteriovenous (AV) crossing site. Although the pathogenesis is unclear, vitreovascular traction might have a significant role in some BRVO cases. The purpose of present study was to determine the incidence of vitreoretinal traction at the obstruction site in patients diagnosed with BRVO. Methods In this prospective observational case–control study, 32 consecutive BRVO patients were studied with spectral-domain optical coherence tomography (SD-OCT) to detect the presence of vitreovascular traction or vitreous adherence at the occlusion site. Results SD-OCT directed to the occlusion site revealed a vitreovascular traction at this point ...

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    15. Swept-source anterior segment optical coherence tomography in late-onset capsular block syndrome: High-resolution imaging and morphometric modifications after posterior capsulotomy

      Swept-source anterior segment optical coherence tomography in late-onset capsular block syndrome: High-resolution imaging and morphometric modifications after posterior capsulotomy

      Purpose To study the characteristics of late-onset capsular block syndrome (CBS) using swept-source anterior segment optical coherence tomography (AS-OCT) and assess morphometric variations after treatment with neodymium:YAG (Nd:YAG) laser posterior capsulotomy. Setting Ophthalmology, University of Parma, Parma, Italy. Design Case series. Methods Patients with late-onset CBS had an ophthalmology evaluation, including slitlamp photography and AS-OCT, before and 1 month after ND:YAG laser posterior capsulotomy. The diameter of the anterior capsulorhexis, the posterior displacement of the posterior capsule, and the anterior chamber depth (ACD) were measured using AS-OCT. Measurements before and after Nd:YAG laser posterior capsulotomy were ...

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    16. In vivo Optical Coherence Tomography of Light-Driven Melanosome Translocation in Retinal Pigment Epithelium

      In vivo Optical Coherence Tomography of Light-Driven Melanosome Translocation in Retinal Pigment Epithelium

      Optical coherence tomography (OCT) may revolutionize fundamental investigation and clinical management of age-related macular degeneration and other eye diseases. However, quantitative OCT interpretation is hampered due to uncertain sub-cellular correlates of reflectivity in the retinal pigment epithelium (RPE) and photoreceptor. The purpose of this study was twofold: 1) to test OCT correlates in the RPE, and 2) to demonstrate the feasibility of longitudinal OCT monitoring of sub-cellular RPE dynamics. A high resolution OCT was constructed to achieve dynamic imaging of frog eyes, in which light-driven translocation of RPE melanosomes occurred within the RPE cell body and apical processes. Comparative histological ...

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    17. Inner Macular Hyperreflectivity Demonstrated by Optical Coherence Tomography in Niemann-Pick Disease

      Inner Macular Hyperreflectivity Demonstrated by Optical Coherence Tomography in Niemann-Pick Disease

      We describe spectral-domain optical coherence tomography (OCT; Heidelberg Spectralis) imaging of 3 patients with Niemann-Pick disease type B. This expands the range of previously reported anatomical correlates of the ophthalmoscopic macular halo surrounding the “cherry-red spot.”

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    18. SD-OCT stages of progression of type 2 macular telangiectasia in a patient followed for 3 years

      SD-OCT stages of progression of type 2 macular telangiectasia in a patient followed for 3 years

      Purpose: To describe the natural course of type 2 idiopathic macular telangiectasia (MT) using spectral-domain optical coherence tomography (SD-OCT). Methods: Analysis of the different stages of progression of type 2 MT during a period of 3 years using multimodal imaging, including SD-OCT correlated with angiographic and autofluorescence images. The analysis of the different steps was obtained initially from the first eye, then successively from the fellow eye when progressive changes appeared. Results: The earliest visible alteration at SD-OCT was the interruption of the interface between inner segment and ellipsoid (IS/EL) (stage 1). The second stage was characterized by the ...

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    19. Cleveland Clinic Receives NIH Grant for Interoperative Optical Coherence Tomography for Ophthalmic Surgery

      Cleveland Clinic Receives NIH Grant for Interoperative Optical Coherence Tomography for Ophthalmic Surgery

      Cleveland Clinic Received a 2013 NIH Grant for $203,124 for Interoperative Optical Coherence Tomography for Ophthalmic Surgery. The principal investigator is Justis Ehlers. The program began in 2013 and ends in 2018. Below is a summary of the proposed work. Project Summary Optical coherence tomography (OCT) has revolutionized the management of ophthalmic diseases with the precise anatomic information it provides with non-invasive imaging. The high-resolution cross-sectional tissue details make OCT a natural complement to ophthalmic surgery. Intraoperative OCT (iOCT) has the potential to provide real-time feedback to surgeons thus improving surgical care and outcomes. This research activity will focus ...

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    20. Macular spectral domain optical coherence tomography findings in Tanzanian endemic optic neuropathy

      Macular spectral domain optical coherence tomography findings in Tanzanian endemic optic neuropathy

      Bilateral optic neuropathy in Dar es Salaam is now considered endemic and is estimated to affect 0.3–2.4% of young adults. The condition is characterized by a subacute bilateral loss of central vision of unknown aetiology. Findings of spectral domain optical coherence tomography have not previously been reported for these patients. All patients diagnosed with endemic optic neuropathy over a 2-year period at the Muhimbili National Hospital underwent spectral domain optical coherence tomography macular imaging. Scans were graded qualitatively for severity of retinal nerve fibre layer loss as well as the presence of microcystic macular changes, which have ...

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    21. Choroidal Thickness Measurement in Children Using Optical Coherence Tomography

      Choroidal Thickness Measurement in Children Using Optical Coherence Tomography

      Purpose: To measure choroidal thickness (CT) in children of various ages by using spectral optical coherence tomography with enhanced depth imaging and to investigate the association between subfoveal CT and ocular axial length, age, gender, weight, and height in children. Methods: Healthy children were prospectively included between May and August 2012. Optical coherence tomography with the enhanced depth imaging system (Spectralis, Heidelberg, Germany) was used for choroidal imaging at nine defined points of the macula of both eyes. Axial length was measured using IOLMaster (Carl Zeiss Meditec, Dublin, CA). Height, weight, and refraction were recorded. Interobserver agreement in readings was ...

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    22. Efficacy of intacs intrastromal corneal ring segment relative to depth of insertion evaluated with anterior segment optical coherence tomography

      Efficacy of intacs intrastromal corneal ring segment relative to depth of insertion evaluated with anterior segment optical coherence tomography

      AIM: To evaluate the effect of implantation depth of Intacs microthin prescription inserts (Addition Technology Inc, Fremont, California) on visual and topographic outcomes in patients with post- laser-assisted in situ keratomileusis (LASIK) ectasias. SETTINGS AND DESIGN: Retrospective, observational case series. MATERIALS AND METHODS: In this case series, 16 eyes of 12 patients were evaluated. All cases were post-LASIK ectasia that had undergone intrastromal corneal ring segment (ICRS) implantation. The planned insertion depth was 70% of stromal thickness using a manual dissector. At least 12 months postoperatively, all eyes underwent Visante (Carl Zeiss Meditec) AS-OCT to determine insertion depth. Cases were ...

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    23. Sclerochoroidal Calcification Is Primarily a Scleral Condition Based on Enhanced Depth Imaging Optical Coherence Tomography

      Sclerochoroidal Calcification Is Primarily a Scleral Condition Based on Enhanced Depth Imaging Optical Coherence Tomography

      Sclerochoroidal calcification (SC) is found in elderly white individuals with calcium pyrophosphate deposition in the sclera and/or choroid, appearing as a typical yellow subretinal mass usually along the retinal vascular arcades. 1 - 4 Most cases are idiopathic, but some have a systemic relationship. 1 - 2 We review multimodal imaging findings of SC.

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    24. Longitudinal spectral domain optical coherence tomography changes in eyes with intraocular lymphoma

      Longitudinal spectral domain optical coherence tomography changes in eyes with intraocular lymphoma

      Background Cases of patients with primary intraocular lymphoma (PIOL) were retrospectively analyzed to describe the longitudinal intra-retinal morphological changes in PIOL as visualized on images obtained by spectral domain optical coherence tomography (SD-OCT). Results In a retrospective case series, Heidelberg Spectralis SD-OCT images obtained in the longitudinal evaluation of patients with biopsy-proven PIOL were analyzed and assessed. The images were graded for the presence of macular edema (ME), pigment epithelial detachment (PED), subretinal fluid (SRF), and hyperreflective signals. SD-OCT scans of five eyes from five patients were assessed. Patients showed signs of inflammation, such as ME and SRF, which were ...

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