1. 1-24 of 159 1 2 3 4 5 6 7 »
    1. The findings of optical coherence tomography of retinal degeneration in relation to the morphological and electroretinographic features in RPE65−/− mice

      The findings of optical coherence tomography of retinal degeneration in relation to the morphological and electroretinographic features in RPE65−/− mice

      Purpose Mutations of the gene encoding RPE65 cause Leber congenital amaurosis (LCA) retinitis pigmentosa (RP). The optical coherence tomography (OCT) is increasingly utilized to noninvasively evaluate various types of retinal diseases, including RP. The present study was conducted to characterize the OCT findings of the RPE65 −/− mice—an animal model of LCA and RP—in relation to the morphological features based on histological and electron microscopic findings as well as electroretinography (ERG) features. Materials and methods RPE65 −/− mice were employed as a model of retinal degeneration. C57BL/6J mice were used as a wild-type control. OCT was performed on the ...

      Read Full Article
    2. 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 ...

      Read Full Article
    3. Segmental inner macular layer analysis with spectral-domain optical coherence tomography for early detection of normal tension glaucoma

      Segmental inner macular layer analysis with spectral-domain optical coherence tomography for early detection of normal tension glaucoma

      Purpose To segment the inner macular layers (IML) and compare the discriminating abilities of the macular and peripapillary retinal nerve fiber layer (mRNFL and pRNFL, respectively) thicknesses in patients with early-stage normal tension glaucoma (NTG). Design Cross-sectional study Methods Forty-nine normal subjects and 69 preperimetric glaucoma (PPG) and 60 NTG patients were enrolled. Spectral-domain optical coherence tomography (SD-OCT) was used to obtain pRNFL and macular thickness parameters and segment the IML in all subjects. Area under the receiver operating characteristic (AUROC) curves were used to compare the diagnostic capabilities of different parameters. Results The pRNFL, total macular layer (TML), mRNFL ...

      Read Full Article
    4. Comparison of repeatability of swept-source and spectral-domain optical coherence tomography for measuring inner retinal thickness in retinal disease

      Comparison of repeatability of swept-source and spectral-domain optical coherence tomography for measuring inner retinal thickness in retinal disease

      Purpose To compare repeatability between SS-OCT and SD-OCT for measurement of macular, macular retinal nerve fiber (mRNFL), and ganglion cell-inner plexiform layer (GC-IPL) thickness in various retinal diseases. Methods One hundred and fourteen eyes of 114 subjects were investigated. Seventy-eight eyes with retinal disease and 36 normal eyes underwent two consecutive measurements of macular, mRNFL, and GC-IPL thickness using SS-OCT and SD-OCT. The data were obtained using the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol. The eyes with retinal diseases were divided into three subgroups according to central macular thickness (CMT) for analysis. The intraclass correlation coefficient (ICC) was calculated ...

      Read Full Article
    5. Analyzing the impact of glaucoma on the macular architecture using spectral-domain optical coherence tomography

      Analyzing the impact of glaucoma on the macular architecture using spectral-domain optical coherence tomography

      Purpose Using spectral domain optical coherence tomography (SD-OCT) the retina can be segmented automatically to visualize all retinal layers. In glaucoma chronically elevated intraocular pressure leads to a decline of retinal ganglion cells (RGC) which changes retinal architecture. The goal of these analyses was to gain insight into the changes induced by glaucoma within all macular layers using SD-OCT within a closely circumscribed glaucoma cohort. Materials and methods SD-OCT measurements with automated retinal layer segmentation were performed in both eyes of primary open-angle glaucoma patients with a defined monocular absolute visual field scotoma in the central 10° of the visual ...

      Read Full Article
    6. Better medicine through machine learning: What’s real, and what’s artificial?

      Better medicine through machine learning: What’s real, and what’s artificial?

      Artificial intelligence (AI) as a field emerged in the 1960s when practitioners across the engineering and cognitive sciences began to study how to develop computational technologies that, like people, can perform tasks such as sensing, learning, reasoning, and taking action. Early AI systems relied heavily on expert-derived rules for replicating how people would approach these tasks. Machine learning (ML), a subfield of AI, emerged as research began to leverage numerical techniques integrating principles from computing, optimization, and statistics to automatically “learn” programs for performing these tasks by processing data: hence the recent interest in “big data.” Although progress in AI ...

      Read Full Article
    7. Live human assessment of depth-dependent corneal displacements with swept-source optical coherence elastography

      Live human assessment of depth-dependent corneal displacements with swept-source optical coherence elastography

      Purpose To assess depth-dependent corneal displacements in live normal subjects using optical coherence elastography (OCE). Methods A corneal elastography method based on swept-source optical coherence tomography (OCT) was implemented in a clinical prototype. Low amplitude corneal deformation was produced during OCT imaging with a linear actuator-driven lens coupled to force transducers. A cross-correlation algorithm was applied to track frame-by-frame speckle displacement across horizontal meridian scans. Intra-measurement force and displacement data series were plotted against each other to produce local axial stiffness approximations, k , defined by the slope of a linear fit to the force/displacement data (ignoring non-axial contributions from ...

      Read Full Article
    8. Comparison of axial length using a new swept-source optical coherence tomography-based biometer - ARGOS with partial coherence interferometry- based biometer -IOLMaster among school children

      Comparison of axial length using a new swept-source optical coherence tomography-based biometer - ARGOS with partial coherence interferometry- based biometer -IOLMaster among school children

      Purpose To compare the axial length measurements obtained by a new swept source optical coherence tomography based biometer-ARGOS with partial coherence interferometry based biometer -IOL master in school children between the ages of 11–17. Methods A prospective, cross-sectional, device comparison study was conducted in a school vision screening program comparing the axial length (AL) and corneal curvature (K) measurements obtained by two biometers- ARGOS and IOL master. Children with 6/9 vision or better, without any ocular abnormalities were included in the study. Two trained optometrists performed the measurements and were masked for the outcome measures. Results The sample ...

      Read Full Article
    9. Comparison of visual assessment and computer image analysis of intracoronary thrombus type by optical coherence tomography

      Comparison of visual assessment and computer image analysis of intracoronary thrombus type by optical coherence tomography

      Background Analysis of intracoronary thrombus type by optical coherence tomography (OCT) imaging is highly subjective. We aimed to compare a newly developed image analysis method to subjective visual classification of thrombus type identified by OCT. Methods Thirty patients with acute ST elevation myocardial infarction were included. Thrombus type visually classified by two independent readers was compared with analysis using QCU-CMS software. Results Repeatability of the computer-based measurements was good. By using a ROC, area under curve values for discrimination of white and red thrombi were 0.92 (95% confidence intervals (CI) 0.83–1.00) for median attenuation, 0.96 ...

      Read Full Article
    10. Spectral domain optical coherence tomography as an adjunctive tool for screening Behçet uveitis

      Spectral domain optical coherence tomography as an adjunctive tool for screening Behçet uveitis

      Background This study investigated the association of central macular thickness (CMT) and macular volume (MV) with severity of Behçet uveitis in the absence of macular edema (ME). Methods This retrospective, interventional study included a total 131 treatment-naïve Behçet patients with varying degree of uveitis in the absence of ME. The mean CMT and MV were obtained by spectral domain optical coherence tomography (SD ODT). The patients were classified according to the anatomical classification of Behçet uveitis. The main outcome measure was comparison of mean CMT and MV with the types of Behçet uveitis. Results Sixty ...

      Read Full Article
    11. Optical coherence tomography findings in patients prior to cataract surgery regarded as unremarkable with ophthalmoscopy

      Optical coherence tomography findings in patients prior to cataract surgery regarded as unremarkable with ophthalmoscopy

      Purpose To investigate the feasibility and diagnostic benefit of routinely performed preoperative macular spectral-domain (SD-) optical coherence tomography (OCT) for the detection of macular pathology in patients with normal biomicroscopic funduscopy prior to cataract surgery. Methods Prospective, single center study. A total of 162 eyes of 123 consecutive patients referred for cataract surgery with a visual acuity better than 20/100, absence of macular symptoms such as metamorphopsia, no history of previous intravitreal procedures and a normal funduscopic appearance on biomicroscopy underwent an additional SD-OCT-examination prior to cataract surgery. OCT-scans were classified in three categories: normal, degenerative vitreous changes without ...

      Read Full Article
    12. Prevalence and type of artefact with spectral domain optical coherence tomography macular ganglion cell imaging in glaucoma surveillance

      Prevalence and type of artefact with spectral domain optical coherence tomography macular ganglion cell imaging in glaucoma surveillance

      Article Authors Metrics Comments Media Coverage Abstract Introduction Methods Results Discussion Supporting information Acknowledgments References Reader Comments (0) Media Coverage (0) Figures Abstract Purpose The ganglion cell analysis (GCA) of the CIRRUS TM HD-OCT (Carl Zeiss, Meditec; Dublin, CA) provides measurement of the macular ganglion cell-inner plexiform layer (GCIPL) thickness. This study determined the frequency of scan artefacts and errors in GCIPL imaging in individuals undergoing HD-OCT surveillance for glaucoma. Method A total of 1439 eyes from 721 subjects enrolled in a prospective study assessing predictors of glaucoma progression underwent macular GCIPL imaging with the CIRRUS HD-OCT at recruitment. The ...

      Read Full Article
    13. Corneal endothelium features in Fuchs’ Endothelial Corneal Dystrophy: A preliminary 3D anterior segment optical coherence tomography study

      Corneal endothelium features in Fuchs’ Endothelial Corneal Dystrophy: A preliminary 3D anterior segment optical coherence tomography study

      Purpose To evaluate the feasibility of 3D anterior segment optical coherence tomography (AS-OCT) for the detection of corneal endothelial features in patients with Fuchs’ Endothelial Corneal Dystrophy (FECD). Methods Twenty patients with clinical diagnosis of FECD (group A), and 20 control subjects (group B) were enrolled. In all patients a complete ophthalmological examination was performed, including best corrected visual acuity (BCVA), slit lamp examination for subjective grading of FECD and corneal endothelial specular microscopy. A 512x128 AS-OCT cube centered on the corneal apex was performed, and then the inner surface of the cornea was visualized and analyzed individually. Results Overall ...

      Read Full Article
    14. Optical coherence tomography is a useful tool in the differentiation between true edema and pseudoedema of the optic disc

      Optical coherence tomography is a useful tool in the differentiation between true edema and pseudoedema of the optic disc

      Purpose To assess the usefulness of spectral-domain optical coherence tomography (SD-OCT) peripapillary retinal nerve fiber layer (RNFL) thickness measurement in discriminating early phase optic disc edema (ODE) from pseudoedema (PODE). Methods Hospital-based, multicenter, cross-sectional study involving external patients referred for recent identification of “presumed ODE”. Patients underwent SD-OCT optic nerve head (ONH) RNFL thickness measurement at their first evaluation. In 155 of these, the causative etiology was subsequently ascertained and the respective eyes (one per patient) were assigned to the ODE (95 eyes) or PODE (60 eyes) group. Admission SD-OCT data were retrieved and used for the analysis. ROC curve ...

      Read Full Article
      Mentions: UCLA
    15. Optical coherence tomography is a useful tool in the differentiation between true edema and pseudoedema of the optic disc

      Optical coherence tomography is a useful tool in the differentiation between true edema and pseudoedema of the optic disc

      Purpose To assess the usefulness of spectral-domain optical coherence tomography (SD-OCT) peripapillary retinal nerve fiber layer (RNFL) thickness measurement in discriminating early phase optic disc edema (ODE) from pseudoedema (PODE). Methods Hospital-based, multicenter, cross-sectional study involving external patients referred for recent identification of “presumed ODE”. Patients underwent SD-OCT optic nerve head (ONH) RNFL thickness measurement at their first evaluation. In 155 of these, the causative etiology was subsequently ascertained and the respective eyes (one per patient) were assigned to the ODE (95 eyes) or PODE (60 eyes) group. Admission SD-OCT data were retrieved and used for the analysis. ROC curve ...

      Read Full Article
    16. Pilot study for three-dimensional assessment of laminar pore structure in patients with glaucoma, as measured with swept source optical coherence tomography

      Pilot study for three-dimensional assessment of laminar pore structure in patients with glaucoma, as measured with swept source optical coherence tomography

      Purpose To develop a method to quantify, based on swept-source optical coherence tomography (OCT), the 3D structure of the laminar pores in patients with glaucoma. Methods This retrospective study examined 160 laminar pores from 8 eyes of 8 cases: 4 normal subjects and 4 open-angle glaucoma (OAG) patients. We reconstructed 3D volume data for a 3 x 3 mm disc, using a method similar to OCT angiography, and segmented the structure of the lamina cribrosa. Then, we manually segmented each laminar pore in sequential C-scan images (>90 slices at 2.6-micron intervals) with VCAT5 (RIKEN, Japan). We compared the control ...

      Read Full Article
      Mentions: Masahiro Akiba
    17. The use of optical coherence tomography for the detection of ocular toxicity by ethambutol

      The use of optical coherence tomography for the detection of ocular toxicity by ethambutol

      Objectives To evaluate, through (OCT), alterations in retinal thickness, secondary to use of ethambutol in the treatment of patients with tuberculosis. In addition to studying the use of simpler semiological tools, such as Amsler and Ishihara, in the screening of these cases. Methods Thirty patients with ethambutol were recruited from the reference service of tuberculosis treatment at the Federal University of Espírito Santo from May 2015 to July 2016. After clinical history, the following parameters were analyzed; best corrected visual acuity, biomicroscopy, tonometry, photomotor reflex testing, Ishihara test, Amsler’s grid test, color digital retinography and optical coherence tomography ...

      Read Full Article
    18. Retinal blood flow reduction after panretinal photocoagulation in Type 2 diabetes mellitus: Doppler optical coherence tomography flowmeter pilot study

      Retinal blood flow reduction after panretinal photocoagulation in Type 2 diabetes mellitus: Doppler optical coherence tomography flowmeter pilot study

      To use a Doppler optical coherence tomography (DOCT) flowmeter to investigate segmental retinal blood flow (RBF) and sum of the segmental RBFs (SRBF) changes after panretinal photocoagulation (PRP) was used to treat type 2 diabetes mellitus with severe diabetic retinopathy (DR). Data from five patients with proliferative DR (PDR) (mean age 51.9 ± 10.5 years) was analyzed. The vessel diameter (D), average velocity (V), and retinal blood flow (RBF) in veins were measured using a DOCT flowmeter before and four weeks after PRP. Segmental RBF from inferotemporal (IT), superotemporal (ST), inferonasal (IN), and superonasal (SN) veins were measured, and ...

      Read Full Article
    19. Hyperreflective foci on optical coherence tomography associate with treatment outcome for anti-VEGF in patients with diabetic macular edema

      Hyperreflective foci on optical coherence tomography associate with treatment outcome for anti-VEGF in patients with diabetic macular edema

      Purpose To investigate the relationship between baseline number of hyperreflective foci (HF) on spectral domain optical coherence tomography (SD-OCT) in patients with diabetic macular edema (DME), as well as the dynamics of HF during treatment with anti-vascular endothelial growth factor (VEGF), and treatment response. Methods We evaluated patients diagnosed with DME scheduled for treatment with intravitreal bevacizumab. Eyes were classified as adequate or insufficient treatment responders based on logMAR visual acuity improvement and central retinal thickness (CRT) decrease after three consecutive injections. Associations between number of HF at baseline and treatment response, the change in HF over the course of ...

      Read Full Article
    20. Intraframe motion correction for raster-scanned adaptive optics images using strip-based cross-correlation lag biases

      Intraframe motion correction for raster-scanned adaptive optics images using strip-based cross-correlation lag biases

      In retinal raster imaging modalities, fixational eye movements manifest as image warp, where the relative positions of the beam and retina change during the acquisition of single frames. To remove warp artifacts, strip-based registration methods–in which fast-axis strips from target images are registered to a reference frame–have been applied in adaptive optics (AO) scanning light ophthalmoscopy (SLO) and optical coherence tomography (OCT). This approach has enabled object tracking and frame averaging, and methods have been described to automatically select reference frames with minimal motion. However, inconspicuous motion artifacts may persist in reference frames and propagate themselves throughout the ...

      Read Full Article
    21. Comparison of methods to quantify macular and peripapillary vessel density in optical coherence tomography angiography

      Comparison of methods to quantify macular and peripapillary vessel density in optical coherence tomography angiography

      Purpose To compare macular and peripapillary vessel density values calculated on optical coherence tomography angiography (OCT-A) images with different algorithms, elaborate conversion formula, and compare the ability to discriminate healthy from affected eyes. Methods Cross-sectional study of healthy subjects, patients with diabetic retinopathy, and glaucoma patients (44 eyes in each group). Vessel density in the macular superficial capillary plexus (SCP), deep capillary plexus (DCP), and the peripapillary radial capillary plexus (RCP) were calculated with seven previously published algorithms. Systemic differences, diagnostic properties, reliability, and agreement of the methods were investigated. Results Healthy eyes exhibited higher vessel density values in all ...

      Read Full Article
    22. Repeatability, reproducibility and agreement of foveal avascular zone measurements using three different optical coherence tomography angiography devices

      Repeatability, reproducibility and agreement of foveal avascular zone measurements using three different optical coherence tomography angiography devices

      Purpose To evaluate the repeatability, the reproducibility and the agreement of foveal avascular zone (FAZ) measurements using three different optical coherence tomography angiography (OCT-A) devices. Procedures This prospective study included 24 eyes of 24 healthy volunteers. OCT-A imaging was performed using RTVue XR Avanti, Canon OCT-HS100 and Spectralis OCT-A. Repeated measurements were performed under the same conditions on two separate days, and the area of the FAZ was determined and analyzed using the above devices. Results All three devices showed a high ICC and there was no significant difference between the ICCs (pairwise comparison) of the three devices (Optovue–Canon ...

      Read Full Article
    23. Quantitative optical coherence tomography angiography biomarkers for neovascular age-related macular degeneration in remission

      Quantitative optical coherence tomography angiography biomarkers for neovascular age-related macular degeneration in remission

      Purpose To characterize quantitative optical coherence tomography angiography (OCT-A) parameters in active neovascular age-related macular degeneration (nAMD) patients under treatment and remission nAMD patients. Design Retrospective, cross-sectional study. Participants One hundred and four patients of whom 72 were in Group 1 (active nAMD) and 32 in Group 2 (remission nAMD) based on SD-OCT (Spectral Domain OCT) qualitative morphology. Methods This study was conducted at the Centre Ophtalmologique de l’Odeon between June 2016 and December 2017. Eyes were analyzed using SD-OCT and high-speed (100 000 A-scans/second) 1050-nm wavelength swept-source OCT-A. Speckle noise removal and choroidal neovascularization (CNV) blood flow ...

      Read Full Article
    24. Cataract significantly influences quantitative measurements on swept-source optical coherence tomography angiography imaging

      Cataract significantly influences quantitative measurements on swept-source optical coherence tomography angiography imaging

      Purpose To analyze retinal blood flow before and after cataract surgery using swept-source optical coherence tomography angiography (SS-OCTA). Methods Prospective observational study. Consecutive patients were recruited and scanned using SS-OCTA before and after cataract surgery. Laser flare photometry were performed post-surgery. Perfusion and vessel density of superficial (SCP) and deep capillary plexuses (DCP) of the 3 × 3 mm images as well as foveal avascular zone (FAZ) measurements were assessed. Vessel continuity, vessel visibility and presence of artefacts were evaluated by two blinded graders using a predefined grading protocol. Results Thirteen eyes of 12 patients met the inclusion criteria. There was ...

      Read Full Article
    1-24 of 159 1 2 3 4 5 6 7 »
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks