1. 1-24 of 225 1 2 3 4 5 6 7 8 9 10 »
    1. Optical coherence tomography angiography in healthy children: A comparison of macular structure

      Optical coherence tomography angiography in healthy children: A comparison of macular structure

      Purpose: The purpose of the present study was to investigate the perfusion density (PD) of macular superficial (SCP) and deep capillary plexus (DCP), the size of foveal avascular zone (FAZ) and central macular thickness (CMT) in healthy children using optical coherence tomography angiography (OCT-A). Patients and methods: About 206 eyes of 111 children were analyzed. The correlation of gestational age (GA), birth weight (BW), age, sex, refractive errors, and visual acuity (VA) with OCT-A parameters were investigated. Results: The mean PD of the fovea and the mean FAZ area of SCP were 17.1% (DS: 4.26) and 234.47 ...

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    2. Evaluation of choroidal thickness in children with acute asthma attack by optical coherence tomography

      Evaluation of choroidal thickness in children with acute asthma attack by optical coherence tomography

      Objective: To evaluate the change in central choroidal thickness in children with asthma attack before and after treatment with β 2 agonists. Materials and methods: About 100 eyes of 50 patients (5-17 years old) with visual acuity of 20/20 who had no retinal, choroidal, and systemic comorbidity were examined by enhanced depth optical coherence tomography (EDI-OCT) before and after asthma attack treatment. Sixty eyes of 30 healthy children of similar age and gender were evaluated as the control group. The central choroidal thickness, peak expiratory flow (PEF), forced expiratory volume 1(FEV 1 ), oxygen saturation, and heart rate were evaluated ...

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    3. Optical coherence tomography angiography in amblyopia: A critical update on current understandings and future perspectives

      Optical coherence tomography angiography in amblyopia: A critical update on current understandings and future perspectives

      Optical coherence tomography angiography (OCTA) is a non-invasive tool to assess the retino-choroidal vasculature in vivo. It tracks the red blood cell movement and maps the vasculature in quick succession. In routine, diabetic retinopathy, age related macular degeneration, central serous chorioretinopathy, and others are commonly being studied to unveil its clinic role. On the other hand, amblyopia is a condition where the visual acuity is subnormal due to non-organic causes in the eye. But the OCTA studies till now have shown variable changes along retino-choroidal vasculature. Hence, to comprehend the existing literature knowledge, a systematic literature search was carried out ...

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    4. Successful optical coherence tomography-guided treatment in a 19-year-old patient with ST-segment elevation myocardial infarction caused by plaque erosion

      Successful optical coherence tomography-guided treatment in a 19-year-old patient with ST-segment elevation myocardial infarction caused by plaque erosion

      ST-segment elevation myocardial infarction is a type of coronary atherosclerotic heart disease, and its pathophysiological mechanism is formation of lipid plaques. We report a 19-year-old patient with ST-segment elevation myocardial infarction caused by plaque erosion, but he did not have any common traditional risk factors of lipid plaques. His treatment was guided by optical coherence tomography. He received successful treatment and had a good prognosis. Optical coherence tomography can be used to help understand the pathogenesis of myocardial infarction and visualize the real lumen.

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    5. Normative intercapillary distance and vessel density data in the temporal retina assessed by wide-field spectral-domain optical coherence tomography angiography

      Normative intercapillary distance and vessel density data in the temporal retina assessed by wide-field spectral-domain optical coherence tomography angiography

      A limitation of conventional optical coherence tomography angiography (OCTA) is the limited field of view normally used in data acquisition. As the technology improves, larger fields of view that capture information away from the macular are being explored in order to provide an enhanced ability to detect pathology. However, normative measurements for important OCTA metrics like vessel density and intercapillary distance are not currently well-characterized in the peripheral retina. In this prospective study, we measured vessel density and intercapillary distance of the superficial vascular complex, ganglion cell layer plexus, and deep capillary plexus in montaged macular/temporal scans from 53 ...

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    6. Evaluation of macular and optic nerve head parameters in amblyopic eyes: An optical coherence tomography study

      Evaluation of macular and optic nerve head parameters in amblyopic eyes: An optical coherence tomography study

      Purpose: To evaluate morphological differences in retinal nerve fibers layers (RNFL), optic nerve head (ONH), ganglion cell complex (GCC), and macular thickness between amblyopic and normal eyes from spectral domain optical coherence tomography (SD-OCT). Methods: Of 234 eyes of 117 children, four groups emerged: group A (162 eyes of 81 non-amblyopic subjects); group B (32 fellow eyes of 32 subjects with monolateral amblyopia); group C (32 amblyopic eyes of 32 subjects affected by monolateral amblyopia); group D (8 amblyopic eyes of 4 subjects with bilateral amblyopia). Patients underwent SD-OCT for ONH parameters, RNFL, GCC and macular thickness, retina map, and ...

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    7. Intraretinal, sub-retinal, and sub-retinal pigmented epithelium fluid in non-exudative age-related macular degeneration: follow-up with OCT imaging

      Intraretinal, sub-retinal, and sub-retinal pigmented epithelium fluid in non-exudative age-related macular degeneration: follow-up with OCT imaging

      Background/objectives: To evaluate the presence and evolution of fluid in non-exudative age-related macular degeneration (AMD) through serial OCT. Subjects/methods: A retrospective analysis of eyes with non-exudative AMD with a minimum of 4 year follow-up was done. Parameters including intraretinal fluid (IRF), subretinal fluid (SRF), and sub-retinal pigment epithelium (RPE) fluid (SRPEF); subfoveal choroidal thickness (SFCT) and type of drusen were evaluated using optical coherence tomography (OCT) scans at baseline and follow up visits. Results: Seventy-two eyes (in 63 patients) were followed up for an average of 5.83 ± 2.17 years. A total of 26/72 (36%) and ...

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    8. OCT retinal angiography features in patients with rheumatoid arthritis: A pilot study

      OCT retinal angiography features in patients with rheumatoid arthritis: A pilot study

      Purpose: To evaluate the superficial (SCP) and deep retinal capillary plexus (DCP) by mean of optical coherence tomography angiography (OCTA) in treatment-naïve patients affected by rheumatoid arthritis (RA). Methods: Between March 2019 and January 2020, patients with recent diagnosis of "definite RA" based on 2010 Rheumatoid Arthritis Classification Criteria were included in a Prospective, observational single center case-control study carried out at G.B. Bietti Foundation. Data were compared with those of 16 healthy age- and sex-matched subjects. Values of the vessel density (VD) of SCP and DCP, central foveal thickness (CFT), foveal avascular zone (FAZ) were collected by ...

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    9. Machine learning in optical coherence tomography angiography

      Machine learning in optical coherence tomography angiography

      Optical coherence tomography angiography (OCTA) offers a noninvasive label-free solution for imaging retinal vasculatures at the capillary level resolution. In principle, improved resolution implies a better chance to reveal subtle microvascular distortions associated with eye diseases that are asymptomatic in early stages. However, massive screening requires experienced clinicians to manually examine retinal images, which may result in human error and hinder objective screening. Recently, quantitative OCTA features have been developed to standardize and document retinal vascular changes. The feasibility of using quantitative OCTA features for machine learning classification of different retinopathies has been demonstrated. Deep learning-based applications have also been ...

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    10. Optical coherence tomography angiography application to pigmented iris: Could a new index quantify blood flow?

      Optical coherence tomography angiography application to pigmented iris: Could a new index quantify blood flow?

      Purpose: To assess the blood flow and vascular visibility of irises in relation to pigmentation and pupil size, using an anterior segment optical coherence tomography angiography (OCTA). Materials and methods: This is a cross-sectional study. OCTA images were acquired in the nasal and temporal quadrants from a cohort of 30 healthy subjects in photopic (miosis) and scotopic (mydriasis) conditions. Patients were divided according to iris color (less pigmented: group L vs more pigmented: group D). Vascular parameters (vessel density (VD), vessel length density (VLD), fractal dimension (FD)) were applied and compared among groups L and D, location and different pupil ...

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    11. Three-dimensional segmentation and depth-encoded visualization of choroidal vasculature using swept-source optical coherence tomography

      Three-dimensional segmentation and depth-encoded visualization of choroidal vasculature using swept-source optical coherence tomography

      The choroid provides nutritional support for the retinal pigment epithelium and photoreceptors. Choroidal dysfunction plays a major role in several of the most important causes of vision loss including age-related macular degeneration, myopic degeneration, and pachychoroid diseases such as central serous chorioretinopathy and polypoidal choroidal vasculopathy. We describe an imaging technique using depth-resolved swept-source optical coherence tomography (SS-OCT) that provides full-thickness three-dimensional (3D) visualization of choroidal anatomy including topographical features of individual vessels. Enrolled subjects with different clinical manifestations within the pachychoroid disease spectrum underwent 15 mm × 9 mm volume scans centered on the fovea. A fully automated method segmented ...

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    12. Optical coherence tomography angiography indicates subclinical retinal disease in neuromyelitis optica spectrum disorders

      Optical coherence tomography angiography indicates subclinical retinal disease in neuromyelitis optica spectrum disorders

      Background: Neuromyelitis optica spectrum disorders (NMOSD) are neuroinflammatory diseases of the central nervous system. Patients suffer from recurring relapses and it is unclear whether relapse-independent disease activity occurs and whether this is of clinical relevance. Objective: To detect disease-specific alterations of the retinal vasculature that reflect disease activity during NMOSD. Methods: Cross-sectional analysis of 16 patients with NMOSD, 21 patients with relapsing-remitting multiple sclerosis, and 21 healthy controls using retinal optical coherence tomography (OCT), optical coherence tomography angiography (OCT-A), measurement of glial fibrillary acidic protein (GFAP) serum levels, and assessment of visual acuity. Results: Patients with NMOSD but not multiple ...

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    13. Optical coherence tomography angiography of choroidal nodules in neurofibromatosis type-1: A case series

      Optical coherence tomography angiography of choroidal nodules in neurofibromatosis type-1: A case series

      Purpose: To describe optical coherence tomography angiography (OCTA) findings in the retina and choroid of patients with neurofibromatosis type 1 (NF1). Methods: We describe a series of four patients diagnosed with NF1 and choroidal nodules who underwent a comprehensive ophthalmic evaluation including a retinal multimodal imaging study based on retinography, near-infrared reflectance imaging (NIR), enhanced depth imaging (EDI) optical coherence tomography (OCT) and OCTA. Results: Patients were three women and one man aged 36-47 years. In all patients, the choroidal nodules were not visible in retinographies but easily detectable with NIR, appearing as multiple bright patches. On OCTA, we observed ...

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    14. Navigated single-capture 3D and cross-sectional wide-field OCT of the mid and peripheral retina and vitreoretinal interface

      Navigated single-capture 3D and cross-sectional wide-field OCT of the mid and peripheral retina and vitreoretinal interface

      Purpose: Assess the mid and peripheral neuroretina and vitreoretinal interface using a novel Navigated Single-Capture 3D and Cross-Sectional Wide-Field Swept-Source Optical Coherence Tomography (WF SS-OCT) technology with correlation to Multi-Wavelength Ultra-Widefield Imaging (MW UWFI) and Histopathology reference. Methods: Retrospective observational study. A total of 74 patients (148 eyes) were imaged using WF SS-OCT and Navigated Single-Capture twelve 23 mm cross-sectional radial scan pattern at 15° intervals. Image diagnosis included: congenital hypertrophy of the retinal pigment epithelium, choroidal nevus, ora serrata pearls, retinal tuft, lattice, snail track, cobblestone degeneration, retinal hole, retinal tear, degenerative retinoschisis, peripheral laser retinopexy, white without pressure ...

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    15. How do intracranial tumors associated with visual pathways affect quadrant and sectoral based optical coherence tomography measurements: The effect of intracranial tumors on RNFL and GC-IPL thickness

      How do intracranial tumors associated with visual pathways affect quadrant and sectoral based optical coherence tomography measurements: The effect of intracranial tumors on RNFL and GC-IPL thickness

      Aim: To investigate the quantitative sectoral and regional changes of retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GC-IPL) thickness in different types of intracranial tumors associated with visual pathways. Methods: This comparative retrospective study included 58 eyes of 30 patients with intracranial tumors and the data of 62 eyes of 31 healthy subjects. The RNFL and GCIPL thicknesses were analyzed using spectral-domain optical coherence tomography (OCT). The tumors were classified into ones that affect pre-geniculate and post-geniculate pathway. Results: The mean RNFL thickness in temporal quadrant was significantly thinner in eyes with intracranial tumors affecting the pre-geniculate ...

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    16. Comparative study of optical coherence tomography angiography algorithms for rodent retinal imaging

      Comparative study of optical coherence tomography angiography algorithms for rodent retinal imaging

      Optical coherence tomography angiography (OCTA) is a functional extension of optical coherence tomography for non-invasive in vivo three-dimensional imaging of the microvasculature of biological tissues. Several algorithms have been developed to construct OCTA images from the measured optical coherence tomography signals. In this study, we compared the performance of three OCTA algorithms that are based on the variance of phase, amplitude, and the complex representations of the optical coherence tomography signals for rodent retinal imaging, namely the phase variance, improved speckle contrast, and optical microangiography. The performance of the different algorithms was evaluated by comparing the quality of the OCTA ...

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    17. Interpretation of anatomic correlates of outer retinal bands in optical coherence tomography

      Interpretation of anatomic correlates of outer retinal bands in optical coherence tomography

      By providing the sectioning capability to differentiate individual retinal layers, optical coherence tomography (OCT) is revolutionizing eye disease diagnosis and treatment evaluation. A better understanding of the hyper- and hypo-reflective bands in retinal OCT is essential for accurate interpretation of clinical outcomes. In this article, we summarize the interpretations of clinical OCT and adaptive optics (AO) OCT (AO-OCT) of the outer retina in the human eye, and briefly review OCT investigation of the outer retina in animal models. Quantitative analysis of outer retinal OCT bands is compared to established parameters of retinal histology. The literature review and comparative analysis support ...

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    18. Morphometric evaluation and measurements of primary pterygium by anterior segment optical coherence tomography and its relation with astigmatism

      Morphometric evaluation and measurements of primary pterygium by anterior segment optical coherence tomography and its relation with astigmatism

      Purpose: To evaluate the relationship between measurements and various morphometric parameters of primary pterygium on anterior segment optical coherence tomography(AS-OCT) and refractive and keratometric astigmatism. Methods: In this cross-sectional study, patients with primary pterygium were included. The AS-OCT parameters of pterygium consisting of epithelial thickness near apex(µm), apical or head thickness(µm), its thickness at limbus(µm), horizontal length of pterygium(mm), central corneal thickness (µm) and maximum pterygium thickness(mm) were evaluated. Results: Sixty three patients comprising of 63 eyes with a primary pterygium were studied. The mean keratometric and refractive astigmatism were 1.69 ± 3.15 ...

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    19. Comparison of total keratometry with corneal power measured by optical low-coherence reflectometry and placido-dual Scheimpflug system

      Comparison of total keratometry with corneal power measured by optical low-coherence reflectometry and placido-dual Scheimpflug system

      Purpose: To compare the total keratometry (TK) and astigmatism measurements in eyes with cataract using automated keratometry of swept - source optical coherence tomography (ss-OCT), optical low-coherence reflectometry (OLCR), simulated keratometry (SimK), and total corneal power (TCP) of combined placido - dual Scheimpflug imaging system. Setting: The study was conducted at LV Prasad Eye Institute, Hyderabad, India. Design: Retrospective evaluation of electronic medical records of patients who were evaluated for cataract surgery Methods: Twenty-eight eyes of 28 patients were included in the study. All patients evaluated for cataract surgery underwent corneal power measurements using three devices: ssOCT, OLCR, and combined placido - dual ...

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    20. Sensitivity of spectral domain optical coherence tomography in the diagnosis of posterior vitreous detachment in vitreomacular interface disorders: A prospective cohort study

      Sensitivity of spectral domain optical coherence tomography in the diagnosis of posterior vitreous detachment in vitreomacular interface disorders: A prospective cohort study

      Purpose: To evaluate the sensitivity of Spectral Domain Optical Coherence Tomography (SD-OCT) regarding the diagnosis of posterior vitreous detachment (PVD) in vitreomacular interface disorders (VID). Methods: A total of 48 eyes of 48 patients were included in this prospective cohort study. PVD in eyes with VID was investigated. We determined the status of posterior vitreous cortex using slit lamp (SL) biomicroscopy and SD-OCT preoperatively, during vitrectomy and on the intraoperative video recording. Sensitivity and specificity of the examining methods were analysed. Four masked independent examiners participated in this study. Results: PVD was diagnosed in 16 eyes (33.3%) on SD-OCT ...

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    21. Does exogenous androgen use affect the retinal blood flow: An OCTA study in transgender men

      Does exogenous androgen use affect the retinal blood flow: An OCTA study in transgender men

      Purpose: This study aims to investigate the effect of using exogenous androgen on retinal microvascular structures in transgender men. Methods: Retinal microvascular structures of transgender men and healthy women in the control group were visualized with optical coherence tomography angiography (OCTA). Foveal avascular zone (FAZ), superficial capillary vascular density (sCVD), deep capillary vascular density (dCVD), and radial peripapillary capillary (RPC) vascular density were evaluated. Results: Thirty transgender men and 30 healthy women were included in the study. There were no significant differences between transgender men and the control group in terms of FAZ, central macular thickness, parafoveal, and perifoveal retinal ...

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    22. OCT imaging of rod mitochondrial respiration in vivo

      OCT imaging of rod mitochondrial respiration in vivo

      There remains a need for high spatial resolution imaging indices of mitochondrial respiration in the outer retina that probe normal physiology and measure pathogenic and reversible conditions underlying loss of vision. Mitochondria are involved in a critical, but somewhat underappreciated, support system that maintains the health of the outer retina involving stimulus-evoked changes in subretinal space hydration. The subretinal space hydration light–dark response is important because it controls the distribution of vision-critical interphotoreceptor matrix components, including anti-oxidants, pro-survival factors, ions, and metabolites. The underlying signaling pathway controlling subretinal space water management has been worked out over the past 30 ...

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    23. The prognostic role of optical coherence tomography in diabetic macular edema patients undergoing early dexamethasone implant shift

      The prognostic role of optical coherence tomography in diabetic macular edema patients undergoing early dexamethasone implant shift

      Purpose: To determine the prognostic characteristics of optical coherence tomography (OCT) parameters by evaluating diabetic macular edema (DME) patients with early dexamethasone (DEX) shift after three doses of intravitreal ranibizumab (RNB) injection. Methods: Fifty-four eyes of 34 patients who had DEX implant after three doses of RNB were included in this retrospective study. Early DEX shift includes patients who received direct DEX implant replacement after three doses of RNB load. Baseline OCT values and factors affecting best corrected visual acuity (BCVA) and central macular thickness (CMT) response were analyzed with logistic regression analyses. Results: The presence of subretinal fluid and ...

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    24. Optical coherence tomography measurements in patients with systemic hypertension

      Optical coherence tomography measurements in patients with systemic hypertension

      Aim: To evaluate the effect of systemic arterial hypertension (SAH) on retinal optical coherence tomography (OCT) parameters and investigate whether a correlation exists between ambulatory blood pressure monitoring (ABPM) and OCT measurements.Material-methods: 115 SAH patients (225 eyes) and 123 healthy control cases (234 eyes) were included. ABPM was performed on 89 of 115 SAH patients. All patients underwent detailed ophthalmologic examination including imaging with OCT. SAH patients were divided into two groups (dippers, non-dippers) according to their nocturnal blood pressure (BP) reduction, and OCT measurements were compared. Results: Average and superior retinal nerve fiber layer (RNFL) quadrants were significantly ...

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