1. 1-24 of 704 1 2 3 4 ... 28 29 30 »
    1. Investigations on the potential of optical coherence tomography as an imaging tool for eustachian tube

      Investigations on the potential of optical coherence tomography as an imaging tool for eustachian tube

      The purpose of this study was to explore the feasibility of eustachian tube optical coherence tomography (ET-OCT) for imaging the pharyngeal region of the eustachian tube (ET). Ten subjects with ear complaints underwent ET-OCT guided by nasal endoscopy, and ET-OCT examination was performed on both sides of each subject's ETs. The process and resulting images were analysed. Ten subjects ranging from 21 to 73 years old (45 ± 14.77) were enrolled in this study. Eighteen ET-OCT imaging examinations were completed. The mean duration of each examination was 2.80 ± 1.62 min (ranging from 2 to 7 min). There ...

      Read Full Article
    2. Perinatal risk factors associated with central retinal changes in former preterm children on optical coherence tomography angiography

      Perinatal risk factors associated with central retinal changes in former preterm children on optical coherence tomography angiography

      To analyze the relationships between the fixation location and the visual function of idiopathic macular hole (IMH) patients with macular integrity assessment (MAIA) examination preoperatively and 3 months postoperatively. This was a retrospective case analysis. Forty-three eyes of 43 patients diagnosed with IMH were included in this study. The best corrected visual acuity (BCVA) assessments, optical coherence tomography (OCT) and MAIA examinations were performed before surgery and 1 week, 1 month and 3 months after surgery. The relationships between MAIA parameters and visual acuity were assessed by correlation analysis. Grouping by fixation location with the foveola (2°) as the centre ...

      Read Full Article
    3. En face image-based classification of diabetic macular edema using swept source optical coherence tomography

      En face image-based classification of diabetic macular edema using swept source optical coherence tomography

      This retrospective study was performed to classify diabetic macular edema (DME) based on the localization and area of the fluid and to investigate the relationship of the classification with visual acuity (VA). The fluid was visualized using en face optical coherence tomography (OCT) images constructed using swept-source OCT. A total of 128 eyes with DME were included. The retina was segmented into: Segment 1, mainly comprising the inner nuclear layer and outer plexiform layer, including Henle's fiber layer; and Segment 2, mainly comprising the outer nuclear layer. DME was classified as: foveal cystoid space at Segment 1 and no ...

      Read Full Article
    4. Small dome-shaped pigment epithelium detachment in polypoidal choroidal vasculopathy: an under-recognized sign of polypoidal lesions on optical coherence tomography?

      Small dome-shaped pigment epithelium detachment in polypoidal choroidal vasculopathy: an under-recognized sign of polypoidal lesions on optical coherence tomography?

      Purpose To evaluate the diagnostic accuracy of spectral-domain optical coherence tomography (SD-OCT) and swept-source optical coherence tomographic angiography (SS-OCTA) to identify polypoidal lesions in serous or serosanguinous maculopathy. Materials and methods A retrospective review of patients presenting pigment epithelial detachments (PEDs) with the diagnosis of polypoidal choroidal vasculopathy (PCV), neovascular age-related macular degeneration (nAMD), and central serous chorioretinopathy (CSC), all of which underwent SD-OCT, SS-OCTA, and indocyanine green angiography (ICGA). Typical features of polypoidal lesions on SD-OCT included sharply peaked PED, notched PED, and hyperreflective ring underneath PED. SS-OCTA feature was vascularized PEDs on cross-sectional images corresponding to cluster-like structures ...

      Read Full Article
    5. Multi-center clinical study using optical coherence tomography for evaluation of cervical lesions in-vivo

      Multi-center clinical study using optical coherence tomography for evaluation of cervical lesions in-vivo

      In this prospective study of an in-vivo cervical examination using optical coherence tomography (OCT), we evaluated the diagnostic value of non-invasive and real-time OCT in cervical precancerous lesions and cancer diagnosis, and determined the characteristics of OCT images. 733 patients from 5 Chinese hospitals were inspected with OCT and colposcopy-directed biopsy. The OCT images were compared with the histological sections to find out the characteristics of various categories of lesions. The OCT images were also interpreted by 3 investigators to make a 2-class classification, and the results were compared against the pathological results. Various structures of the cervical tissue were ...

      Read Full Article
    6. OCT angiography metrics predict intradialytic hypotension episodes in chronic hemodialysis patients: a pilot, prospective study

      OCT angiography metrics predict intradialytic hypotension episodes in chronic hemodialysis patients: a pilot, prospective study

      In chronic hemodialysis (HD) patients, intradialytic hypotension (IDH) is a complication that increases mortality risk. We run a pilot study to analyzing possible relationships between optical coherence tomography angiography (OCT-A) metrics and IDH with the aim of evaluating if OCT-A could represent a useful tool to stratify the hypotensive risk in dialysis patients. A total of 35 eyes (35 patients) were analyzed. OCT-A was performed before and after a single dialysis session. We performed OCT-A 3 × 3 mm and 6 × 6 mm scanning area focused on the fovea centralis. Patients were then followed up to 30 days (10 HD sessions ...

      Read Full Article
    7. High frequency SD-OCT follow-up leading to up to biweekly intravitreal ranibizumab treatment in neovascular age-related macular degeneration

      High frequency SD-OCT follow-up leading to up to biweekly intravitreal ranibizumab treatment in neovascular age-related macular degeneration

      A remarkable proportion of neovascular age-related macular degeneration (nAMD) patients respond rather poorly to ranibizumab treatment, in spite of the minimum 4-week follow-up and treatment interval. Usually, retreatments are based on nAMD activity as evaluated by Spectral-domain Optical coherence Tomography (SD-OCT), biomicroscopic fundus examination and visual acuity changes. In this prospective pilot study, we aimed to study SD-OCT changes in a high-frequent follow-up manner (weekly (month 0-6), biweekly (month 7-12)) throughout the first year, which consequently led to intravitreal ranibizumab being administered up to biweekly. Best corrected visual acuity (BCVA) was already significantly improved at week 2. Central retinal thickness ...

      Read Full Article
    8. Utilization potential of intraluminal optical coherence tomography for the Eustachian tube

      Utilization potential of intraluminal optical coherence tomography for the Eustachian tube

      Imaging the Eustachian tube is challenging because of its complex anatomy and limited accessibility. This study fabricated a fiber-based optical coherence tomography (OCT) catheter and investigated its potential for assessing the Eustachian tube anatomy. A customized OCT system and an imaging catheter, termed the Eustachian OCT, were developed for visualizing the Eustachian tube. Three male swine cadaver heads were used to study OCT image acquisition and for subsequent histologic correlation. The imaging catheter was introduced through the nasopharyngeal opening and reached toward the middle ear. The OCT images were acquired from the superior to the nasopharyngeal opening before and after ...

      Read Full Article
    9. Optical coherence tomography features of the repair tissue following RPE tear and their correlation with visual outcomes

      Optical coherence tomography features of the repair tissue following RPE tear and their correlation with visual outcomes

      To assess the optical coherence tomography (OCT) features of the repair tissue after retinal pigment epithelial (RPE) tear in neovascular age-related macular degeneration. Retrospective, observational study. Medical and imaging records of patients that developed tears after starting anti-VEGF treatment and with at least 12 months of follow-up were reviewed. OCT reflectivity of the RPE-subretinal hyperreflective tissue (SHT) complex was measured at 6, 12 and 18 months (when available). Reflectivity of the adjacent unaffected RPE-Bruch's membrane was taken as internal reference. Other variables: grade and rip occurrence (early/late); number of intravitreal injections; type of macular neovascularization; sub-macular hemorrhage (SMH ...

      Read Full Article
    10. Applicability of optical coherence tomography angiography (OCTA) imaging in Parkinson’s disease

      Applicability of optical coherence tomography angiography (OCTA) imaging in Parkinson’s disease

      To evaluate the significance of motion artifacts in optical coherence tomography angiography (OCTA) images of patients with Parkinson’s disease (PD) and healthy controls. In this prospective, cross-sectional study subjects with medicated PD (ON) and healthy, age- and gender-matched volunteers were recruited. Participants underwent specific ophthalmological examinations, including OCTA. Angiograms of the superficial retinal capillary plexus were evaluated for the type and frequency of artifacts using a validated motion artifact score (MAS). A total of 30 PD patients (60 eyes), average disease duration of 9.61 ± 5.55 years, and 30 matched, healthy controls (60 eyes) were recruited. Twenty percent ...

      Read Full Article
    11. A pilot study of scleral thickness in central serous chorioretinopathy using anterior segment optical coherence tomography

      A pilot study of scleral thickness in central serous chorioretinopathy using anterior segment optical coherence tomography

      The aim of this study is to compare the scleral thickness of central serous chorioretinopathy (CSC) eyes with controls using anterior segment optical coherence tomography (AS OCT). This prospective case control study included 15 patients (15 eyes) with CSC and 15 age and gender matched healthy subjects. All subjects underwent spectral domain OCT with enhanced depth imaging and swept source AS OCT of temporal sclera. We investigated difference in scleral thickness between the two groups and relationship between choroidal and scleral thickness. Among the 15 eyes in the study group, 1 eye had acute CSC, 4 had recurrent CSC, 7 ...

      Read Full Article
    12. Optical coherence tomography and multiphoton microscopy offer new options for the quantification of fibrotic aortic valve disease in ApoE -/- mice

      Optical coherence tomography and multiphoton microscopy offer new options for the quantification of fibrotic aortic valve disease in ApoE -/- mice

      Aortic valve sclerosis is characterized as the thickening of the aortic valve without obstruction of the left ventricular outflow. It has a prevalence of 30% in people over 65 years old. Aortic valve sclerosis represents a cardiovascular risk marker because it may progress to moderate or severe aortic valve stenosis. Thus, the early recognition and management of aortic valve sclerosis are of cardinal importance. We examined the aortic valve geometry and structure from healthy C57Bl6 wild type and age-matched hyperlipidemic ApoE -/- mice with aortic valve sclerosis using optical coherence tomography (OCT) and multiphoton microscopy (MPM) and compared results with histological ...

      Read Full Article
    13. Spatio-temporal alterations in retinal and choroidal layers in the progression of age-related macular degeneration (AMD) in optical coherence tomography

      Spatio-temporal alterations in retinal and choroidal layers in the progression of age-related macular degeneration (AMD) in optical coherence tomography

      Age-related macular degeneration (AMD) is the predominant cause of vision loss in the elderly with a major impact on ageing societies and healthcare systems. A major challenge in AMD management is the difficulty to determine the disease stage, the highly variable progression speed and the risk of conversion to advanced AMD, where irreversible functional loss occurs. In this study we developed an optical coherence tomography (OCT) imaging based spatio-temporal reference frame to characterize the morphologic progression of intermediate age-related macular degeneration (AMD) and to identify distinctive patterns of conversion to the advanced stages macular neovascularization (MNV) and macular atrophy (MA ...

      Read Full Article
    14. Higher choroidal thickness and lower choriocapillaris blood flow signal density based on optical coherence tomography angiography in diabetics

      Higher choroidal thickness and lower choriocapillaris blood flow signal density based on optical coherence tomography angiography in diabetics

      Diabetes mellitus (DM) is one of the fastest growing chronic diseases in the world and one of the main causes of vision loss. Whether or not diabetic choroidopathy (DC) is involved in the initiation and progression of diabetic ocular complications needs to be explored. We included 54 diabetic eyes from 36 diabetic patients, and 54 healthy eyes from 32 control subjects after propensity scores matching. All of the subjects were given pupil light and dark adaptation examination and optical coherence tomography angiography (OCTA). Scotopic pupil diameter (SPD), pupil contraction amplitude, and velocity of pupil contraction of the diabetic group were ...

      Read Full Article
    15. Quantitative OCT angiography findings according to pattern classification of type 1 neovascularization exudative age-related macular degeneration

      Quantitative OCT angiography findings according to pattern classification of type 1 neovascularization exudative age-related macular degeneration

      Objectives To define neovascularization (NV) patterns and their association with exudative activity in type 1 neovascular age-related macular degeneration (NVAMD). Methods In optical coherence tomography angiography (OCTA) images of type 1 NVAMD, we stratified NV patterns according to whether they contained core vessel (C+/C−) and fine branching vessels (F+/F−) or not into C − F +, C + F +, and C + F − groups. Qualitative analyses assessing the status of peripheral tiny branching, inner branching capillaries, arcade, loop, and perilesional halo and quantitative analyses considering the NV area, length, density, and numbers of junctions and endpoints (open-ended vessels) in NV were conducted ...

      Read Full Article
    16. Macular irregularities of optical coherence tomographic vertical cross sectional images in school age children

      Macular irregularities of optical coherence tomographic vertical cross sectional images in school age children

      The purpose of this study was to compare the incidences of macular irregularities of elementary school (ES) and junior high school (JHS) students. This was a prospective cross-sectional observational study of 122 right eyes of 122 ES students (8-9 years) and 173 right eyes of 173 JHS students (12-13 years). Vertical cross-sectional images of the macula were obtained by optical coherence tomography. The eyes were classified based on the vertical symmetry of the posterior pole, and then sub-classified as convex-, flat-, concave-, or dome-shaped based on the direction of the curvature of the retinal pigment epithelium. One hundred and two ...

      Read Full Article
    17. Longitudinal optical coherence tomography to visualize the in vivo response of middle ear biofilms to antibiotic therapy

      Longitudinal optical coherence tomography to visualize the in vivo response of middle ear biofilms to antibiotic therapy

      Studying the impact of antibiotic treatment on otitis media (OM), the leading cause of primary care office visits during childhood, is critical to develop appropriate treatment strategies. Tracking dynamic middle ear conditions during antibiotic treatment is not readily applicable in patients, due to the limited diagnostic techniques available to detect the smaller amount and variation of middle ear effusion (MEE) and middle ear bacterial biofilm, responsible for chronic and recurrent OM. To overcome these challenges, a handheld optical coherence tomography (OCT) system has been developed to monitor in vivo response of biofilms and MEEs in the OM-induced chinchilla model, the ...

      Read Full Article
    18. Precise higher-order reflectivity and morphology models for early diagnosis of diabetic retinopathy using OCT images

      Precise higher-order reflectivity and morphology models for early diagnosis of diabetic retinopathy using OCT images

      This study proposes a novel computer assisted diagnostic (CAD) system for early diagnosis of diabetic retinopathy (DR) using optical coherence tomography (OCT) B-scans. The CAD system is based on fusing novel OCT markers that describe both the morphology/anatomy and the reflectivity of retinal layers to improve DR diagnosis. This system separates retinal layers automatically using a segmentation approach based on an adaptive appearance and their prior shape information. High-order morphological and novel reflectivity markers are extracted from individual segmented layers. Namely, the morphological markers are layer thickness and tortuosity while the reflectivity markers are the 1st-order reflectivity of the ...

      Read Full Article
    19. Optical coherence tomography angiography and Humphrey field analyser for macular capillary non-perfusion evaluation in branch retinal vein occlusion

      Optical coherence tomography angiography and Humphrey field analyser for macular capillary non-perfusion evaluation in branch retinal vein occlusion

      We non-invasively evaluated macular non-perfused areas (m-NPAs) of branch retinal vein occlusion (BRVO) using optical coherence tomography (OCT) angiography and the Humphrey visual field analyser 10-2 programme (HFA 10-2). We enrolled 30 patients (30 eyes) with macular oedema secondary to BRVO. OCT angiography was used to photograph the macula at 6 × 6-mm; sizes of m-NPAs in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were measured in four areas. For HFA 10-2, we divided the actual measurement threshold of 68 points into four areas and calculated the mean central visual field sensitivity (CVFS). The correlation between the mean ...

      Read Full Article
    20. Assessing accommodative presbyopic biometric changes of the entire anterior segment using single swept-source OCT image acquisitions

      Assessing accommodative presbyopic biometric changes of the entire anterior segment using single swept-source OCT image acquisitions

      Background/Objectives To evaluate biometric changes throughout the anterior chamber during accommodation and presbyopia using single image acquisition swept-source anterior-segment optical coherence tomography (AS-OCT). Subject/Methods Anterior-segment images were obtained using a new swept-source AS-OCT device (ANTERION, Heidelberg Engineering) from healthy volunteers ( n  = 71) across two centers in this prospective observational case series. In one image acquisition, cornea through posterior lens, including the ciliary muscle on both sides of the right eye, was imaged. Subjects undertook no accommodative effort and −1, −3, and −5 D of target vergence. Two-way repeated measures ANOVA modeling was performed for ciliary muscle measurements, lens ...

      Read Full Article
    21. Diabetic vascular hyperpermeability: optical coherence tomography angiography and functional loss assessments of relationships among retinal vasculature changes

      Diabetic vascular hyperpermeability: optical coherence tomography angiography and functional loss assessments of relationships among retinal vasculature changes

      Our study assessed the influence of vascular permeability on vascular flow density (FD)-correlated retinal sensitivity (RS) in DR. In this cross-sectional, prospective, consecutive study, RS in the extrafoveal macula of DR patient was measured by microperimetry. FD was measured in the total, superficial, and deep capillary plexus layers (TCP, SCP, and DCP) by optical coherence tomography angiography. All measurement points were classified into four categories according to intensity of fluorescein leakage and FD, and the RS reduction was compared. A stratified analysis by retinal thickness (RT) was also performed. Fourteen eyes (14 patients) were enrolled. FDs at 207 RS ...

      Read Full Article
    22. Study of retinal structural–functional relationship in choroideremia using fundus autofluorescence and optical coherence tomography

      Study of retinal structural–functional relationship in choroideremia using fundus autofluorescence and optical coherence tomography

      Objective The objective of this study was to assess the structural–functional relationship in choroideremia (CHM) patients using optical coherence tomography (OCT) and autofluorescence (AF) images. Methods In this study, 53 eyes of 28 CHM patients were included. Demographic, ocular and clinical fundus features were recorded. Fundus AF and OCT images were analysed. Patients were classified into two groups based on AF features: group 1, CHM patients where the foveal island was present and group 2, CHM patients where the foveal island was absent. Inner and outer retinal layer thicknesses, retinal pigment epithelium (RPE) and subfoveal choroidal thickness (SFCT) were ...

      Read Full Article
    23. Submicron spatial resolution optical coherence tomography for visualising the 3D structures of cells cultivated in complex culture systems

      Submicron spatial resolution optical coherence tomography for visualising the 3D structures of cells cultivated in complex culture systems

      Three-dimensional (3D) configuration of in vitro cultivated cells has been recognised as a valuable tool in developing stem cell and cancer cell therapy. However, currently available imaging approaches for live cells have drawbacks, including unsatisfactory resolution, lack of cross-sectional and 3D images, and poor penetration of multi-layered cell products, especially when cells are cultivated on semitransparent carriers. Herein, we report a prototype of a full-field optical coherence tomography (FF-OCT) system with isotropic submicron spatial resolution in en face and cross-sectional views that provides a label-free, non-invasive platform with high-resolution 3D imaging. We validated the imaging power of this prototype by ...

      Read Full Article
    24. Automated quantification of posterior vitreous inflammation: optical coherence tomography scan number requirements

      Automated quantification of posterior vitreous inflammation: optical coherence tomography scan number requirements

      Quantifying intraocular inflammation is crucial in managing uveitis patients. We assessed the minimum B-scan density for reliable automated vitreous intensity (VI) assessment, using a novel approach based on optical coherence tomography (OCT). OCT volume scans centered on the macula were retrospectively collected in patients with uveitis. Nine B-scans per volume scan at fixed locations were automatically analyzed. The following B-scan selections were compared against the average score of 9 B-scans per volume scan as a reference standard: 1/3/5/7 central scans (1c/3c/5c/7c), 3 widely distributed scans (3w). Image data of 49 patients (31 females) were ...

      Read Full Article
    1-24 of 704 1 2 3 4 ... 28 29 30 »
  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