1. 1-24 of 96 1 2 3 4 »
    1. Optical coherence tomography angiography of the peripapillary capillaries in primary open-angle and normal-tension glaucoma

      Optical coherence tomography angiography of the peripapillary capillaries in primary open-angle and normal-tension glaucoma

      Objectives To evaluate the vascular architecture of the radial peripapillary capillaries (RPCs) and its relation with visual function in patients with open-angle glaucoma (OAG) and normal-tension glaucoma using spectral-domain optical coherence tomography (SD-OCT) angiography. Subjects and methods Clear OCT angiography images of blood vessels in the optic disc and peripapillary retina were obtained from 52 patients (52 eyes) aged 55.42±10.64 (range 28–72) years with primary OAG. The mean spherical equivalent was -3.19±2.31 diopters, and the mean deviation (MD) of the central 24/30-2 threshold test using the Humphrey Field Analyzer (HFA) was -10 ...

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    2. Assessment of tilt and decentration of crystalline lens and intraocular lens relative to the corneal topographic axis using anterior segment optical coherence tomography

      Assessment of tilt and decentration of crystalline lens and intraocular lens relative to the corneal topographic axis using anterior segment optical coherence tomography

      Purpose To investigate the tilt and decentration of the crystalline lens and the intraocular lens (IOL) relative to the corneal topographic axis using anterior segment ocular coherence tomography (AS-OCT). Methods A sample set of 100 eyes from 49 subjects (41 eyes with crystalline lenses and 59 eyes with IOLs) were imaged using second generation AS-OCT (CASIA2, TOMEY) in June and July 2016 at Okayama University. Both mydriatic and non-mydriatic images were obtained, and the tilt and decentration of the crystalline lens and the IOL were quantified. The effects of pupil dilation on measurements were also assessed. Results The crystalline lens ...

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    3. Comparison of peripapillary vessel density between preperimetric and perimetric glaucoma evaluated by OCT-angiography

      Comparison of peripapillary vessel density between preperimetric and perimetric glaucoma evaluated by OCT-angiography

      Purpose To determine peripapillary vessel density in eyes with perimetric glaucoma (PG) or preperimetric glaucoma (PPG) compared to normal controls using optical coherence tomography-angiography (OCT-A). Methods We recruited 13 patients with unilateral perimetric normal-tension glaucoma (NTG) and fellow preperimetric NTG showing only inferotemporal retinal nerve fiber layer (RNFL) defect in red-free RNFL photography in both eyes. We also enrolled 9 healthy controls. Using OCT-A, radial peripapillary capillary densities at inferotemporal and superotemporal regions were evaluated. Paired comparison of peripapillary vessel density was performed for PG eye, PPG eye, and normal eye. Results A total of 26 eyes of the 13 ...

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    4. Changes in the anterior segment after cycloplegia with a biometer using swept-source optical coherence tomography

      Changes in the anterior segment after cycloplegia with a biometer using swept-source optical coherence tomography

      The aim of this study was to investigate changes in the anterior segment of the eye after cycloplegia. A biometer combined with swept-source optical coherence tomography (SSOCT) was used for measurements. Patients with strabismus or amblyopia who underwent cycloplegia were included. The axial length, central corneal thickness, anterior chamber depth, and lens thickness were measured with the biometer–SSOCT system before and after cycloplegia. Altogether, 10 eyes of 10 patients (mean age 7.20 ± 3.08 years, range 4–14 years) were evaluated. The mean measurements before cycloplegia were 22.75 ± 0.96 mm axial length, 516 ± 33 μm central ...

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    5. In vivo analysis of glaucoma-related features within the optic nerve head using enhanced depth imaging optical coherence tomography

      In vivo analysis of glaucoma-related features within the optic nerve head using enhanced depth imaging optical coherence tomography

      Structural differences between optic nerve head (ONH) parameters in glaucomatous and non-glaucomatous eyes has been documented, however the association between such parameters in patients with different disease stages is yet to be elucidated. We investigated the relationship between different laminar and prelaminar ONH structures using enhanced depth imaging spectral-domain optical coherence tomography (EDI OCT) in a population with and without glaucoma. In this observational case-control study, we prospectively enrolled healthy individuals and glaucomatous patients with different disease stages. All participants underwent EDI OCT imaging (Heidelberg Engineering). Following ONH parameters were measured on serial vertical B-scans by two examiners masked to ...

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    6. Glaucomatous changes in lamina pores shape within the lamina cribrosa using wide bandwidth, femtosecond mode-locked laser OCT

      Glaucomatous changes in lamina pores shape within the lamina cribrosa using wide bandwidth, femtosecond mode-locked laser OCT

      Purpose The lamina cribrosa (LC) is known to play a critical role in the pathogenesis of glaucoma. Although it has been reported that striae-shaped or slit-shaped lamina pores are more frequent in eyes with primary open angle glaucoma (POAG), this observation is based only on fundus photography. The primary object of this study is to perform layer-by-layer comparisons of the shape of lamina pores within the LC in vivo. Design Cross-sectional study. Methods Optic nerve head B-scans were obtained using custom-made broad-wavelength optical coherence tomography with a mode-locked laser. A total of 300 single B-scans per eye were obtained and ...

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    7. Label-free three-dimensional imaging of Caenorhabditis elegans with visible optical coherence microscopy

      Label-free three-dimensional imaging of Caenorhabditis elegans with visible optical coherence microscopy

      Fast, label-free, high-resolution, three-dimensional imaging platforms are crucial for high-throughput in vivo time-lapse studies of the anatomy of Caenorhabditis elegans , one of the most commonly used model organisms in biomedical research. Despite the needs, methods combining all these characteristics have been lacking. Here, we present label-free imaging of live Caenorhabditis elegans with three-dimensional sub-micrometer resolution using visible optical coherence microscopy (visOCM). visOCM is a versatile optical imaging method which we introduced recently for tomography of cell cultures and tissue samples. Our method is based on Fourier domain optical coherence tomography, an interferometric technique that provides three-dimensional images with high sensitivity ...

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    8. Normative database for separate inner retinal layers thickness using spectral domain optical coherence tomography in Caucasian population

      Normative database for separate inner retinal layers thickness using spectral domain optical coherence tomography in Caucasian population

      Article Authors Metrics Comments Related Content Abstract Introduction Methods Results Discussion Supporting information Acknowledgments References Reader Comments (0) Media Coverage Figures Abstract Purpose Develop the first normative database of the thickness of every inner retinal layer in the macular area in a healthy, Caucasian population between 18 to 87 years old, using Spectralis Optical Coherence Tomography (OCT). Methods On this transversal, observational study, 300 patients between 18 to 87 years old and without an ophthalmological condition were recruited. Macular OCT scans were performed on all patients (Spectralis OCT, Heidelberg Engineering). An axial length measurement, and keratometry were performed using an ...

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    9. Cholesterol crystal depth in coronary atherosclerotic plaques: A novel index of plaque vulnerability using optical frequency domain imaging

      Cholesterol crystal depth in coronary atherosclerotic plaques: A novel index of plaque vulnerability using optical frequency domain imaging

      Background The involvement of cholesterol crystals (CCs) in plaque progression and destabilization of atherosclerotic plaques has been recently recognized. This study aimed to evaluate the association between the intraplaque localization of CCs and plaque vulnerability. Methods We investigated 55 acute coronary syndrome (ACS) and 80 stable angina pectoris (stable AP) lesions using optical frequency domain imaging (OFDI) prior to percutaneous coronary intervention. The distance between CCs and the luminal surface of coronary plaques was defined as CC depth. Results Although the incidence of CCs had similar frequencies in the ACS and stable AP groups (95% vs. 89%, p = 0.25 ...

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    10. Quantitative analysis of retinal layers on three-dimensional spectral-domain optical coherence tomography for pituitary adenoma

      Quantitative analysis of retinal layers on three-dimensional spectral-domain optical coherence tomography for pituitary adenoma

      Purpose To quantitatively investigate the characteristics of eyes with pituitary adenoma presented by three-dimensional (3D) spectral-domain optical coherence tomography (SD-OCT) using three common indices, including thickness, optical intensity ratio, and optical intensity attenuation coefficient (OIAC). Methods The SD-OCT database of 38 patients with pituitary adenoma and 39 normal controls were included in the study. Quadrantal and average measurements of thickness, optical intensity ratio, and OIAC were calculated for macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL) combined with inner plexiform layer (IPL) (GCIPL) and/or the collective ganglion cell complex (GCC). The parameters of patients and controls were ...

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    11. Age and axial length on peripapillary retinal nerve fiber layer thickness measured by optical coherence tomography in nonglaucomatous Taiwanese participants

      Age and axial length on peripapillary retinal nerve fiber layer thickness measured by optical coherence tomography in nonglaucomatous Taiwanese participants

      Purpose This study investigates the influence of age and axial length (AL) on the peripapillary retinal nerve fiber layer (RNFL) thickness, as measured by optical coherence tomography (OCT). Methods Healthy patients visiting an eye clinic at a county hospital were recruited. All participants underwent comprehensive ophthalmologic examinations, and their retinas were scanned using 3D OCT-1000. In total, 223 patients with 446 eyes were included. The mean age and AL were 42.07 ± 13.16 (21–76) years and 25.38 ± 1.73 (21.19–30.37) mm, respectively. Results The average RNFL thickness decreased by 2.71 μm for every ...

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    12. Reconstruction of stented coronary arteries from optical coherence tomography images: Feasibility, validation, and repeatability of a segmentation method

      Reconstruction of stented coronary arteries from optical coherence tomography images: Feasibility, validation, and repeatability of a segmentation method

      Optical coherence tomography (OCT) is an established catheter-based imaging modality for the assessment of coronary artery disease and the guidance of stent placement during percutaneous coronary intervention. Manual analysis of large OCT datasets for vessel contours or stent struts detection is time-consuming and unsuitable for real-time applications. In this study, a fully automatic method was developed for detection of both vessel contours and stent struts. The method was applied to in vitro OCT scans of eight stented silicone bifurcation phantoms for validation purposes. The proposed algorithm comprised four main steps, namely pre-processing, lumen border detection, stent strut detection, and three-dimensional ...

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    13. Measurement of macular structure-function relationships using spectral domain-optical coherence ...

      Measurement of macular structure-function relationships using spectral domain-optical coherence ...

      Background Retinal ganglion cell (RGC) death is a common cause of loss of vision during glaucoma. Pattern electroretinogram (PERG) is an objective measure of the central retinal function that correlates with macular GCL thickness. The aim of this study is to determine possible relationships between the N95 amplitude of pattern electroretinogram (PERG amp ) and macular ganglion cell/inner plexiform layer thickness (GCIPLT). Methods and findings This was a retrospective and comparative study including 74 glaucoma patients (44 early stage and 30 advanced stage cases) and 66 normal control subjects. Macular GCIPLT was measured using Cirrus spectral domain-optical coherence tomography. Standard ...

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    14. Comparison of spectral-domain optical coherence tomography for intra-retinal layers thickness ...

      Comparison of spectral-domain optical coherence tomography for intra-retinal layers thickness ...

      Purpose To compare intra-retinal layer thickness measurements between eyes with no or mild diabetic retinopathy (DR) and age-matched controls using Spectralis spectral-domain optical coherence tomography (SD-OCT). Methods Cross-sectional observational analysis study. High-resolution macular volume scans (30° * 25°) were obtained for 133 type 2 diabetes mellitus (T2DM) patients with no DR, 42 T2DM patients with mild DR and 115 healthy controls. The mean thickness was measured in all 9 Early Treatment Diabetic Retinopathy Study (ETDRS) sectors for 8 separate layers, inner retinal layer (IRL), outer retinal layer (ORL) and total retina (TR), after automated segmentation. The ETDRS grid consisted of three ...

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    15. OCT-angiography: A qualitative and quantitative comparison of 4 OCT-A devices

      OCT-angiography: A qualitative and quantitative comparison of 4 OCT-A devices

      Article Authors Metrics Comments Related Content Abstract Introduction Methods Results Discussion Supporting information Acknowledgments Author Contributions References Reader Comments (0) Media Coverage Figures Abstract Purpose To compare the quality of four OCT-angiography(OCT-A) modules. Method The retina of nineteen healthy volunteers were scanned with four OCT-devices (Topcon DRI-OCT Triton Swept-source OCT, Optovue RTVue-XR, a prototype Spectralis OCT2, Heidelberg-Engineering and Zeiss Cirrus 5000-HD-OCT). The device-software generated en-face OCT-A images of the superficial (SCP) and deep capillary plexuses (DCP) were evaluated and scored by 3 independent retinal imaging experts. The SCP vessel density was assessed using Angiotool-software. After the inter-grader reliability assessment ...

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    16. Influence of eye biometrics and corneal micro-structure on noncontact tonometry

      Influence of eye biometrics and corneal micro-structure on noncontact tonometry

      Purpose Tonometry is widely used as the main screening tool supporting glaucoma diagnosis. Still, its accuracy could be improved if full knowledge about the variation of the corneal biomechanical properties was available. In this study, Optical Coherence Tomography (OCT) speckle statistics are used to infer the organisation of the corneal micro-structure and hence, to analyse its influence on intraocular pressure (IOP) measurements. Methods Fifty-six subjects were recruited for this prospective study. Macro and micro-structural corneal parameters as well as subject age were considered. Macro-structural analysis included the parameters that are associated with the ocular anatomy, such as central corneal thickness ...

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    17. Quantitative microvascular analysis of retinal venous occlusions by spectral domain optical coherence tomography angiography

      Quantitative microvascular analysis of retinal venous occlusions by spectral domain optical coherence tomography angiography

      Purpose To quantitatively evaluate the retinal microvasculature in human subjects with retinal venous occlusions (RVO) using optical coherence tomography angiography (OCTA). Design Retrospective, cross-sectional, observational case series. Participants Sixty subjects (84 eyes) were included (20 BRVO, 14 CRVO, 24 unaffected fellow eyes, and 26 controls). Methods OCTA was performed on a prototype, spectral domain-OCTA system in the 3x3mm central macular region. Custom software was used to quantify morphology and density of retinal capillaries using four quantitative parameters. The vasculature of the segmented retinal layers and nonsegmented whole retina were analyzed. Main outcome measures Fractal dimension (FD), vessel density (VD), skeletal ...

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    18. Measurements of the parapapillary atrophy zones in en face optical coherence tomography images

      Measurements of the parapapillary atrophy zones in en face optical coherence tomography images

      Objective To measure the parapapillary atrophy (PPA) area in en face images obtained with swept-source optical coherence tomography (SS-OCT), and to evaluate its relationship to glaucoma, myopia, and age in non-highly myopic subjects. Design Retrospective, cross-sectional study. Participants Fifty eyes of 30 subjects with open-angle glaucoma (G group) and forty-three eyes of 26 healthy control subjects (C group). Eyes with high myopia (spherical equivalent refractive error ≤ -8 diopters or axial length ≥ 26.5 mm) were excluded. Methods Mean age ± standard deviation was 59.9 ± 12.4 years. The beta zone and the gamma zone PPA areas were measured in en ...

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    19. Validation of full-field optical coherence tomography in distinguishing malignant and benign tissue in resected pancreatic cancer specimens

      Validation of full-field optical coherence tomography in distinguishing malignant and benign tissue in resected pancreatic cancer specimens

      Background Pancreatic cancer is the fourth leading cause of cancer-related mortality in the United States. The minority of patients can undergo curative-intended surgical therapy due to progressive disease stage at time of diagnosis. Nonetheless, tumor involvement of surgical margins is seen in up to 70% of resections, being a strong negative prognostic factor. Real-time intraoperative imaging modalities may aid surgeons to obtain tumor-free resection margins. Full-field optical coherence tomography (FF-OCT) is a promising diagnostic tool using high-resolution white-light interference microscopy without tissue processing. Therefore, we composed an atlas of FF-OCT images of malignant and benign pancreatic tissue, and investigated the ...

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    20. Polarization image segmentation of radiofrequency ablated porcine myocardial tissue

      Polarization image segmentation of radiofrequency ablated porcine myocardial tissue

      Optical polarimetry has previously imaged the spatial extent of a typical radiofrequency ablated (RFA) lesion in myocardial tissue, exhibiting significantly lower total depolarization at the necrotic core compared to healthy tissue, and intermediate values at the RFA rim region. Here, total depolarization in ablated myocardium was used to segment the total depolarization image into three (core, rim and healthy) zones. A local fuzzy thresholding algorithm was used for this multi-region segmentation, and then compared with a ground truth segmentation obtained from manual demarcation of RFA core and rim regions on the histopathology image. Quantitative comparison of the algorithm segmentation results ...

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    21. Assessment of the retinal posterior pole in dominant optic atrophy by spectral-domain optical coherence tomography and microperimetry

      Assessment of the retinal posterior pole in dominant optic atrophy by spectral-domain optical coherence tomography and microperimetry

      Background To assess posterior pole (PP) retinal structure in patients with genetically confirmed autosomal dominant optic atrophy (ADOA) using new spectral domain optical coherence tomography (SD-OCT) segmentation technology. To analyze retinal PP thickness in relation to retinal sensitivity data from microperimetry (MP) in ADOA patients. Methods and findings This prospective cross-sectional study included 11 patients with ADOA and 11 age-matched healthy subjects. All participants underwent both a “Posterior Pole” and “peripapillary RNFL (pRNFL)” scanning protocol using SD-OCT. Functional mapping of the PP was also performed using MP. A customized program was implemented in order to achieve accurate superimposition of MP ...

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      Mentions: Nidek
    22. A comparison of the diagnostic ability of vessel density and structural measurements of optical coherence tomography in primary open angle glaucoma

      A comparison of the diagnostic ability of vessel density and structural measurements of optical coherence tomography in primary open angle glaucoma

      Purpose To compare the diagnostic abilities of vessel density measurements of the optic nerve head (ONH), peripapillary and macular regions on optical coherence tomography (OCT) angiography in eyes with primary open angle glaucoma (POAG) with that of the ONH rim area, peripapillary retinal nerve fiber layer (RNFL) thickness and the macular ganglion cell complex (GCC) thickness measurements. Methods In a cross sectional study, 78 eyes of 50 control subjects and 117 eyes of 67 POAG patients underwent vessel density and structural measurements with spectral domain OCT. POAG was diagnosed based on the masked evaluation of optic disc stereo photographs. Area ...

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    23. In vivo images of the epidural space with two- and three-dimensional optical coherence tomography in a porcine model

      In vivo images of the epidural space with two- and three-dimensional optical coherence tomography in a porcine model

      Background No reports exist concerning in vivo optical coherence tomography visualization of the epidural space and the blood patch process in the epidural space. In this study, we produced real-time two-dimensional and reconstructed three-dimensional images of the epidural space by using optical coherence tomography in a porcine model. We also aimed to produce three-dimensional optical coherence tomography images of the dura puncture and blood patch process. Methods Two-dimensional and three-dimensional optical coherence tomography images were obtained using a swept source optical coherence tomography (SSOCT) system. Four laboratory pigs were intubated and ventilated after the induction of general anesthesia. An 18-gauge ...

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      Mentions: Wen-Chuan Kuo
    24. Optical coherence tomography angiography in eyes with good visual acuity recovery after treatment for optic neuritis

      Optical coherence tomography angiography in eyes with good visual acuity recovery after treatment for optic neuritis

      Objective To evaluate the retinal perfusion using optical coherence tomography (OCT) angiography in eyes with good visual acuity recovery after treatment for optic neuritis (ON). Methods Seven eyes of seven patients with good visual acuity recovery after treatment for monocular ON and seven eyes of each fellow eye used as controls were studied. Retinal perfusion around the disc and at the macula was evaluated using OCT angiography. The retinal nerve fiber layer thickness was measured around the disc. The ganglion cell layer complex thickness or the ganglion cell layer plus the inner plexiform layer thickness were measured at the macula ...

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