1. Articles in category: Ophthalmology

    553-576 of 6725 « 1 2 ... 21 22 23 24 25 26 27 ... 279 280 281 »
    1. Variability and Repeatability of Quantitative, Fourier Domain-OCT Doppler Blood Flow in Young and Elderly Healthy Subjects

      Variability and Repeatability of Quantitative, Fourier Domain-OCT Doppler Blood Flow in Young and Elderly Healthy Subjects

      The purpose of this study was to determine the within-session variability and between-session repeatability of spectral Fourier-domain optical coherence tomography (Doppler FD-OCT) Doppler retinal blood flow measurements in young, and elderly subjects. Methods: Doppler FD-OCT blood flow was measured using the RTVue system (Optovue Inc., USA). One eye of each of 20 healthy young (24.7 ± 2.7 years) and 16 healthy elderly (64.6 ± 5.1 years) subjects was randomly selected and the pupil was dilated. The double circular scanning pattern of the RTVue was employed. Six Doppler FD-OCT measurements (i.e. each separate measurement comprising an upper, and ...

      Read Full Article
    2. Anterior Segment Optical Coherence Tomography Parameters in Phacomorphic Angle Closure and Mature Cataracts

      Anterior Segment Optical Coherence Tomography Parameters in Phacomorphic Angle Closure and Mature Cataracts

      Purpose:To describe anterior segment optical coherence tomography (AS-OCT) parameters in phacomorphic angle closure (PMAC) eyes, mature cataract eyes and their fellow eyes, and identify those parameters that could be used to differentiate PMAC eyes from those with mature cataract and no PMAC. Methods:In this cross-sectional study a total of 33 PMAC subjects and 34 control patients with unilateral mature cataracts were enrolled. All patients underwent AS-OCT imaging and A-scan biometry of both eyes. Anterior chamber depth(ACD), anterior chamber area(ACA), iris thickness, iris curvature, lens vault(LV), and angle parameters including angle opening distance(AOD750) and trabecular ...

      Read Full Article
    3. COMBINED HAMARTOMA OF THE RETINA AND RETINAL PIGMENT EPITHELIUM: Findings on Enhanced Depth Imaging Optical Coherence Tomography in Eight Eyes

      COMBINED HAMARTOMA OF THE RETINA AND RETINAL PIGMENT EPITHELIUM: Findings on Enhanced Depth Imaging Optical Coherence Tomography in Eight Eyes

      Purpose: To assess combined hamartoma of the retina and retinal pigment epithelium with enhanced depth imaging optical coherence tomography. Methods: Retrospective, observational cases series in eight eyes of eight patients, with comparison between affected and unaffected eyes regarding enhanced depth imaging optical coherence tomography features of tumor, fovea, and choroid. Results: The mean age at presentation was 7 years. The tumor was macular (n = 5) or extramacular (n = 3). Enhanced depth imaging optical coherence tomography revealed irregularities in inner retina (n = 8) and/or all retinal layers (n = 3), with epiretinal membrane (n = 8), causing an inner retinal sawtooth (mini-peak ...

      Read Full Article
    4. Macular Thickness Measurements using Copernicus Spectral Domain Optical Coherence Tomography

      Macular Thickness Measurements using Copernicus Spectral Domain Optical Coherence Tomography

      Purpose To provide normal macular thickness measurements using Spectral Domain Optical Coherence Tomography (SDOCT, Copernicus, Optopol Technologies, Zawierci, Poland). Methods Fifty eight eyes of 58 healthy subjects were included in this prospective study. All subjects had comprehensive ophthalmic examination including best-corrected visual acuity (BCVA). All the subjects underwent Copernicus SDOCT. Central foveal thickness (CFT) and photoreceptor layer (PRL) thickness were measured and expressed as mean and standard deviation. Mean retinal thickness for each of the 9 regions defined in the Early Treatment Diabetic Retinopathy Study were reported. The data was compared with published literature in Indians using Stratus and Spectralis ...

      Read Full Article
    5. Findings of secondary corneal amyloidosis with ultrahigh-resolution optical coherence tomography

      Findings of secondary corneal amyloidosis  with ultrahigh-resolution optical coherence  tomography

      Purpose: To describe observations by ultrahigh-resolution optical coherence tomography (OCT) in a secondary corneal amyloidosis (SCA) patient with histological analysis of excised tissue. A unique finding under OCT of her fellow eye is also described. Case: A 39-year-old female had suffered from trichiasis in both of her eyes for more than 30 years. Slit-lamp examination showed a milky-white soft mass on her left cornea and a linear opacity on the fellow cornea at the cilia-attached region. OCT demonstrated the presence of a mass region within a thin epithelial layer and no destruction of Bowman’s layer in her left cornea ...

      Read Full Article
    6. Detection and Differentiation of Intraretinal Hemorrhage in Spectral Domain Optical Coherence Tomography

      Detection and Differentiation of Intraretinal Hemorrhage in Spectral Domain Optical Coherence Tomography

      Purpose : The purpose of this study was to classify and detect intraretinal hemorrhage (IRH) in spectral domain optical coherence tomography (SD-OCT). Methods : Initially the presentation of IRH in BRVO-patients in SD-OCT was described by one reader comparing color-fundus (CF) and SD-OCT using dedicated software. Based on these established characteristics, the presence and the severity of IRH in SD-OCT and CF were assessed by two other masked readers and the inter-device and the inter-observer agreement were evaluated. Further the area of IRH was compared. Results : About 895 single B-scans of 24 eyes were analyzed. About 61% of SD-OCT scans and 46 ...

      Read Full Article
    7. Interocular symmetry of retinal nerve fibre layer thickness in healthy eyes: a spectral-domain optical coherence tomographic study

      Interocular symmetry of retinal nerve fibre layer thickness in healthy eyes: a spectral-domain optical coherence tomographic study

      Purpose This study was performed to investigate the interocular symmetry of peripapillary retinal nerve fibre layer (RNFL) thickness, as measured by Cirrus high-definition spectral-domain optical coherence tomography (OCT), in healthy eyes. A wide range of subject ages and refractive errors was examined. Methods The retinal nerve fibre layer thickness was measured in 1,234 healthy eyes from 617 subjects using OCT. Interocular differences (right eye minus left eye) in global area and quadrant nerve fibre layer thicknesses were measured. The effect of age and refractive error on interocular nerve fibre layer thickness difference was also examined. Results Means (and standard ...

      Read Full Article
    8. Rapid, Accurate, and Non-Invasive Measurement of Zebrafish Axial Length and Other Eye Dimensions Using SD-OCT Allows Longitudinal Analysis of Myopia and Emmetropization

      Rapid, Accurate, and Non-Invasive Measurement of Zebrafish Axial Length and Other Eye Dimensions Using SD-OCT Allows Longitudinal Analysis of Myopia and Emmetropization

      Refractive errors in vision can be caused by aberrant axial length of the eye, irregular corneal shape, or lens abnormalities. Causes of eye length overgrowth include multiple genetic loci, and visual parameters. We evaluate zebrafish as a potential animal model for studies of the genetic, cellular, and signaling basis of emmetropization and myopia. Axial length and other eye dimensions of zebrafish were measured using spectral domain-optical coherence tomography (SD-OCT). We used ocular lens and body metrics to normalize and compare eye size and relative refractive error (difference between observed retinal radial length and controls) in wild-type and lrp2 zebrafish. Zebrafish ...

      Read Full Article
    9. Optical coherence tomography and 3-dimensional confocal structured imaging system–guided femtosecond laser capsulotomy versus manual continuous curvilinear capsulorhexis

      Optical coherence tomography and 3-dimensional confocal structured imaging system–guided femtosecond laser capsulotomy versus manual continuous curvilinear capsulorhexis

      Purpose To compare the features of capsulotomy obtained during femtosecond laser–assisted cataract surgery with those of continuous curvilinear capsulorhexis (CCC) obtained using a standard manual technique. Setting Ophthalmology Clinic, Department of Medicine and Science of Ageing, University G. D'Annunzio Chieti-Pescara, Chieti, Italy. Design Prospective randomized clinical study. Methods Candidates for cataract extraction were randomized into 1 of 3 groups as follows: Lensx femtosecond laser–assisted cataract surgery capsulotomy (laser group 1), Lensar femtosecond laser–assisted cataract surgery capsulotomy (laser group 2), and manual CCC (manual group). Results Each group comprised 30 eyes (30 patients). The capsulotomies in laser ...

      Read Full Article
    10. Assessment of choroidal thickness before and after steep Trendelenburg position using swept-source optical coherence tomography

      Assessment of choroidal thickness before and after steep Trendelenburg position using swept-source optical coherence tomography

      Background To evaluate changes in choroidal thickness before and after steep Trendelenburg position (STP, 40° head-down) using automated segmentation software to analyse swept-source optical coherence tomography (SS-OCT) data. Methods The eyes of 20 healthy volunteers underwent a three-dimensional wide scanning protocol with SS-OCT (Topcon, Tokyo, Japan) at baseline, immediately after STP was initiated, and 5, 10 and 15 min after STP; blood pressure and heart rate were measured concurrently. The predictive mean difference was calculated using a generalised linear mixed model that adjusted for potential confounders. Results Mean choroidal thickness significantly and transiently increased immediately (268.18±9.24 μm ...

      Read Full Article
    11. Assessment of laser induction of Bruch's membrane disruption in monkey by spectral-domain optical coherence tomography

      Assessment of laser induction of Bruch's membrane disruption in monkey by spectral-domain optical coherence tomography

      Purpose Laser-induced choroidal neovascularisation is a widely used model for age-related macular degeneration. The success rates of induction have been relatively low in large animals such as monkeys. Our study aimed to investigate the laser-induced damages to the Bruch's membrane of monkeys using the spectral-domain optical coherence tomography (OCT). Methods Laser photocoagulation was performed in the posterior and peripheral fundus of a rhesus monkey using a 532 nm laser. The lesions were examined by fundus photography and spectral-domain OCT immediately after the procedure. Fluorescein angiography was performed after 3 and 4 weeks in the animal to assess the development ...

      Read Full Article
    12. System and method for early detection of diabetic retinopathy using optical coherence tomography

      System and method for early detection of diabetic retinopathy using optical coherence tomography

      A system for the imaging, processing and evaluation of tissues provides prognostic and diagnostic details regarding diseased tissue. A set of quantitative measures were developed and integrated in an image-base analysis software tool designed for OCT images. The system and methods in this invention is significant because it allows assessing the optical properties and structure morphology differences between normal healthy subjects and diabetic patients with retinopathy up to ETDRS level 35 and without retinopathy.

      Read Full Article
    13. Optical Coherence Tomography for the Monitoring of Neovascular Age-Related Macular Degeneration

      Optical Coherence Tomography for the Monitoring of Neovascular Age-Related Macular Degeneration

      Topic To compare the accuracy of optical coherence tomography (OCT) with alternative tests for monitoring neovascular age-related macular degeneration (nAMD) and detecting disease activity among eyes previously treated for this condition. Clinical Relevance Traditionally, fundus fluorescein angiography (FFA) has been considered the reference standard to detect nAMD activity, but FFA is costly and invasive. Replacement of FFA by OCT can be justified if there is a substantial agreement between tests. Methods Systematic review and meta-analysis. The index test was OCT. The comparator tests were visual acuity, clinical evaluation (slit lamp), Amsler chart, color fundus photographs, infrared reflectance, red-free images and ...

      Read Full Article
    14. Aqueous reaction quantification after phacoemulsification: Fourier-domain optical coherence tomography versus slitlamp biomicroscopy

      Aqueous reaction quantification after phacoemulsification: Fourier-domain optical coherence tomography versus slitlamp biomicroscopy

      Purpose To compare anterior chamber cell detection after phacoemulsification between Fourier-domain optical coherence tomography (OCT) and slitlamp biomicroscopy. Design Observational prospective comparative case series. Setting Dr. Agarwal's Eye Hospital and Eye Research Centre, Chennai, India. Methods Eyes with preoperative nuclear opalescence (NO) grades 1 to 3 that had phacoemulsification with posterior chamber intraocular lens implantation were included. Slitlamp biomicroscopy and Fourier-domain OCT (Cirrus HD) of the anterior chamber were performed 1 day postoperatively. The results were evaluated, and a correlation analysis between the results and preoperative NO, effective phacoemulsification time (EPT), postoperative central corneal thickness (CCT), and intraocular pressure ...

      Read Full Article
      Mentions: Amar Agarwal
    15. Correlation of corneal thickness and volume with intraoperative phacoemulsification parameters using Scheimpflug imaging and optical coherence tomography

      Correlation of corneal thickness and volume with intraoperative phacoemulsification parameters using Scheimpflug imaging and optical coherence tomography

      Purpose To evaluate post-phacoemulsification corneal edema using central corneal thickness (CCT) and central corneal volume (CCV) derived from Scheimpflug imaging, optical coherence tomography (OCT), and ultrasound (US) pachymetry and to correlate CCV with phacoemulsification parameters. Setting Department of Ophthalmology, Boston Medical Center, Boston, Massachusetts, USA. Design Prospective case study. Methods Scheimpflug imaging (Pentacam HR), OCT (Cirrus HD-OCT), and US pachymetry (Pachmate) were used to measure the CCT, CCV, and phacoemulsification parameters after uneventful phacoemulsification over a 1-month follow-up. Results In the 16 eyes assessed, the Scheimpflug CCT was less than the US CCT preoperatively ( P =.01) and 1 week postoperatively ...

      Read Full Article
    16. Swept-Source Optical Coherence Tomography Features of Choroidal Nevi

      Swept-Source Optical Coherence Tomography Features of Choroidal Nevi

      Purpose To investigate the morphological characteristics of choroidal nevi using swept-source optical coherence tomography and compare this with enhanced-depth optical coherence tomography. Design Retrospective observational case series Methods One choroidal nevus each from 30 eyes of 30 patients was included and received imaging with swept-source OCT (SS-OCT) and enhanced-depth imaging OCT (EDI-OCT). For SS-OCT, a scan acquisition protocol was utilized involving 12mm horizontal and vertical scans in the posterior fundus. The main outcome measures were morphological features of choroidal nevi obtained with SS-OCT imaging. These features were compared to images obtained with EDI-OCT. A two-tailed Fisher’s exact test was ...

      Read Full Article
    17. Optical Coherence Tomography Assessment of Angle Anatomy Changes After Trabeculectomy in Primary Angle-Closure Glaucoma

      Optical Coherence Tomography Assessment of Angle Anatomy Changes After Trabeculectomy in Primary Angle-Closure Glaucoma

      Purpose: Using anterior chamber optical coherence tomography to evaluate changes in angle anatomy in patients with primary angle-closure glaucoma (PACG) before and after trabeculectomy. Methods: This is a prospective observational study in 38 eyes of 38 patients with PACG, who underwent trabeculectomy. We used customized software to analyze optical coherence tomography images (Visante) of all participants before and after the surgical treatment. Multivariate linear regression analysis was performed for predictors of percentage change in mean angle parameters, including scleral spur angle, angle opening distance, angle recess area, and trabecular-iris surface area. The main outcome measures were changes in angle parameters ...

      Read Full Article
    18. OCT-Derived Comparison of Corneal Thickness Distribution and Asymmetry Differences Between Normal and Keratoconic Eyes

      OCT-Derived Comparison of Corneal Thickness Distribution and Asymmetry Differences Between Normal and Keratoconic Eyes

      Purpose: The aim of this study was to investigate the corneal thickness asymmetry indices in a large pool of patients with keratoconus derived using anterior segment optical coherence tomography (AS-OCT) in comparison with established Scheimpflug imaging-derived keratoconus classification indices. Methods: Six specific indices were comparatively investigated in this study encompassing 2 groups: keratoconic group A (175 eyes) and age- and gender-matched control group B (175 eyes). AS-OCT was used for corneal focal thinning and irregularity indices, namely the superior nasal minus inferior temporal (SN-IT), superior minus inferior (S-I), minimum minus median (Min-Med) focal thinning, and thickness range, defined as the ...

      Read Full Article
    19. Noise-compensated Homotopic Non-local Regularized Reconstruction for Rapid Retinal Optical Coherence Tomography Image Acquisitions

      Noise-compensated Homotopic Non-local Regularized Reconstruction for Rapid Retinal Optical Coherence Tomography Image Acquisitions

      Background Optical coherence tomography (OCT) is a minimally invasive imaging technique, which utilizes the spatial and temporal coherence properties of optical waves backscattered from biological material. Recent advances in tunable lasers and infrared camera technologies have enabled an increase in the OCT imaging speed by a factor of more than 100, which is important for retinal imaging where we wish to study fast physiological processes in the biological tissue. However, the high scanning rate causes proportional decrease of the detector exposure time, resulting in a reduction of the system signal-to-noise ratio (SNR). One approach to improving the image quality of ...

      Read Full Article
    20. CHOROIDAL THICKNESS MEASURED WITH SWEPT SOURCE OPTICAL COHERENCE TOMOGRAPHY BEFORE AND AFTER VITRECTOMY WITH INTERNAL LIMITING MEMBRANE PEELING FOR IDIOPATHIC EPIRETINAL MEMBRANES

      CHOROIDAL THICKNESS MEASURED WITH SWEPT SOURCE OPTICAL COHERENCE TOMOGRAPHY BEFORE AND AFTER VITRECTOMY WITH INTERNAL LIMITING MEMBRANE PEELING FOR IDIOPATHIC EPIRETINAL MEMBRANES

      Purpose: In eyes with epiretinal membranes (ERMs), retinal arteries become dilated and tortuous. This may correlate with the hemodynamics of the affected areas and possibly with choroidal thickness. The aim of this study was to estimate choroidal thickness before and after vitrectomy for idiopathic ERM in the operated eye and in the unaffected fellow eye. Methods: A prospective study of 21 patients with idiopathic ERMs. We obtained swept source optical coherence tomography images that simultaneously evaluated the vitreous, retina, and choroid. We performed choroidal thickness measurements before pars plana vitrectomy with ERM removal and internal limiting membrane peeling. We took ...

      Read Full Article
    21. A comprehensive model for correcting RNFL readings of varying signal strengths in CIRRUS Optical Coherence Tomography (OCT)

      A comprehensive model for correcting RNFL readings of varying signal strengths in CIRRUS Optical Coherence Tomography (OCT)

      Purpose. Develop a model for the CIRRUSTM HD-OCT that allows for the comparison of retinal nerve fiber layer (RNFL) thickness measurements with dissimilar signal strengths (SS) and accounts for test-re-test variability. Methods. RNFLs were obtained in normals using the CIRRUSTM optic disc cube 200x200 protocol during a single encounter. Five RNFL scans were obtained with a SS of 9-10. Diffusion lens filters were used to degrade SS to obtain five scans at each SS group of 7-8, 5-6, and 3-4. The relationship between average RNFL thickness and SS was established and an equation was developed to allow for adjustment of ...

      Read Full Article
    22. Evaluating Dissociated Optic Nerve Fiber Layer Appearance Using En Face Layer Imaging Produced by Optical Coherence Tomography

      Evaluating Dissociated Optic Nerve Fiber Layer Appearance Using En Face Layer Imaging Produced by Optical Coherence Tomography

      Purpose: To investigate the incidence of and risk factors for a dissociated optic nerve fiber layer (DONFL) appearance after pars plana vitrectomy (PPV). Methods: We retrospectively reviewed 189 eyes that underwent PPV with internal limiting membrane removal and judged the presence/absence of an apparent DONFL based on en face layer images produced by spectral-domain optical coherence tomography (SD-OCT). Results: An apparent DONFL was observed in 47 (24.9%) eyes. The incidence of an apparent DONFL was significantly higher in the macular hole (MH) group (76.5%) than in the non-MH group (epiretinal membrane, diabetic macular edema, retinal vein occlusion ...

      Read Full Article
    23. The cellular origins of the outer retinal bands in optical coherence tomography images

      The cellular origins of the outer retinal bands in optical coherence tomography images

      Purpose: To test the recently proposed hypothesis that the second OCT outer retinal band originates from the inner segment ellipsoid, by measuring: 1) thickness of this band within single cones, and 2) its respective distance from the external limiting membrane and outer segment tips. Methods: Adaptive optics OCT images were obtained from four normal subjects. Images were obtained at foveal (2∘) and perifoveal (5∘) locations. Cones (n = 9593) were identified and segmented in three dimensions using custom software. Features corresponding to bands 1, 2, and 3 were automatically identified. Thickness of band 2 was assessed in each cell by fitting ...

      Read Full Article
    24. Abbott Expands Cataract Surgery Product Portfolio through U.S. Distribution Agreement with Carl Zeiss Meditec

      Abbott Expands Cataract Surgery Product Portfolio through U.S. Distribution Agreement with Carl Zeiss Meditec

      Abbott and Carl Zeiss Meditec announced today that they have entered into a nonexclusive commercial collaboration in the United States. Under this agreement, Abbott will offer each company’s suite of cataract surgery products when developing clinical and contracting solutions with customers in the United States. This comprehensive offering, including synergistic diagnostics, visualization systems, lens extraction systems, and intraocular lenses, provides surgeons with access to a complete cataract surgery portfolio to assist them in maximizing visual outcomes and streamlining patient flow. "Together with surgeons, Abbott is committed to delivering unsurpassed visual outcomes to patients," said Murthy Simhambhatla, Ph.D., senior ...

      Read Full Article
    553-576 of 6725 « 1 2 ... 21 22 23 24 25 26 27 ... 279 280 281 »
  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
  2. Popular Articles

  3. Organizations in the News

    1. (3 articles) Thomas Jefferson University
    2. (3 articles) Oregon Health & Science University
    3. (3 articles) National Institutes of Health
    4. (3 articles) University of Miami
    5. (2 articles) Johns Hopkins University
    6. (2 articles) Center for Ophthalmic Optics and Lasers
    7. (2 articles) Tufts University
    8. (1 articles) Yonsei University
    9. (1 articles) Chungnam National University Hospital
    10. (1 articles) Medical University of Vienna
    11. (1 articles) Washington University in St. Louis
    12. (1 articles) Osaka University
  4. People in the News

    1. (3 articles) David Huang
    2. (2 articles) Peter A. Calabresi
    3. (2 articles) Bruno Lumbroso
    4. (2 articles) Carol L. Shields
    5. (2 articles) Marco Rispoli
    6. (1 articles) Linda M. Zangwill
    7. (1 articles) Vadim Backman
    8. (1 articles) Ji Yi
    9. (1 articles) Maria Cristina Savastano
    10. (1 articles) Laura J. Balcer
    11. (1 articles) Hao F. Zhang
    12. (1 articles) Andrew J. Tatham
  5. OCT Companies in the News

    1. (4 articles) Heidelberg Engineering
    2. (4 articles) Carl Zeiss Meditec
    3. (2 articles) Topcon Medical Systems
    4. (1 articles) Tomey Corporation
    5. (1 articles) Optovue
    6. (1 articles) LenSx
    7. (1 articles) Nidek
  6. OCT Products in the News

    1. (5 articles) Zeiss Cirrus HD-OCT
    2. (4 articles) Heidelberg Spectralis
    3. (2 articles) Zeiss Visante OCT
    4. (1 articles) Topcon DRI OCT-1 Atlantis
    5. (1 articles) Optovue RTVue-100
    6. (1 articles) Tomey SS-1000 CASIA