1. Articles from takuya iwasaki

    1-18 of 18
    1. Evaluation of choroidal melanin-containing tissue in healthy Japanese subjects by polarization-sensitive optical coherence tomography

      Evaluation of choroidal melanin-containing tissue in healthy Japanese subjects by polarization-sensitive optical coherence tomography

      In this study, the choroidal melanin content in healthy eyes was evaluated with polarization-sensitive optical coherence tomography (PS-OCT). We evaluated 105 healthy eyes of 105 Japanese subjects. The mean thickness of melanin-containing tissue in the choroid (thickness of MeCh) and the choroidal melanin occupancy rate within a 5-mm circular region from the foveal center were calculated using the degree of polarization uniformity obtained by PS-OCT and compared with the choroidal thickness, patient age, and axial length. To evaluate regional variations, the 5-mm circular region was divided into a center area and an outer ring area, and the outer ring area ...

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    2. Objective evaluation of choroidal melanin loss in patients with Vogt–Koyanagi–Harada disease using polarization-sensitive optical coherence tomography

      Objective evaluation of choroidal melanin loss in patients with Vogt–Koyanagi–Harada disease using polarization-sensitive optical coherence tomography

      In this study, sunset glow fundus was evaluated in patients with Vogt-Koyanagi-Harada (VKH) disease using polarization-sensitive optical coherence tomography (PS-OCT). We evaluated 40 VKH eyes (20 patients) and 59 healthy eyes (59 age-matched controls). VKH eyes were divided into three groups according to color fundus images: sunset (17 eyes), potential sunset (13 eyes), and non-sunset (10 eyes). Choroidal melanin thickness (ChMeT) and the choroidal melanin thickness ratio (ChMeTratio) were calculated based on the degree of polarization uniformity from PS-OCT. ChMeT was significantly lower in sunset eyes than in non-sunset or control eyes (P = 0.003). The ChMeTratios of sunset or ...

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    3. Evaluation of Retinal Pigment Epithelium Layer Change in Vogt-Koyanagi-Harada Disease With Multicontrast Optical Coherence Tomography

      Evaluation of Retinal Pigment Epithelium Layer Change in Vogt-Koyanagi-Harada Disease With Multicontrast Optical Coherence Tomography

      Purpose : Clinical evaluation of retinal pigment epithelium (RPE) change is important for the therapeutic management of chronic Vogt-Koyanagi-Harada (VKH) disease. We evaluated long-term change in the RPE layer in VKH disease, using near-infrared (NIR; 817 nm) images and autofluorescence images at 488 nm (short-wavelength [SW]-AF) and 785 nm (NIR-AF), and compared those images with images from multicontrast optical coherence tomography (MC-OCT). MC-OCT is capable of simultaneous measurement of OCT angiography, polarization-sensitive OCT, and standard OCT. Methods : We evaluated 24 eyes of 12 patients with chronic VKH disease. RPE changes were assessed using NIR, NIR-AF, SW-AF, and MC-OCT imaging performed ...

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    4. Objective evaluation of choroidal melanin contents with polarization-sensitive optical coherence tomography

      Objective evaluation of choroidal melanin contents with polarization-sensitive optical coherence tomography

      We non-invasively evaluated choroidal melanin contents in human eyes with PS-OCT. We calculated the percentage area of low DOPU in the choroidal interstitial stroma for Vogt-Koyanagi- Harada disease with sunset glow fundus, without sunset glow fundus, control group and tessellated fundus with high myopia. The mean percentage area of low DOPU in the sunset group was significantly lower than the other groups. PS-OCT provides an in vivo objective evaluation of choroidal melanin loss in vivo human eyes.

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    5. Noninvasive vascular imaging of ruptured retinal arterial macroaneurysms by Doppler optical coherence tomography

      Noninvasive vascular imaging of ruptured retinal arterial macroaneurysms by Doppler optical coherence tomography

      Background To describe Doppler optical coherence tomography (OCT) imaging of ruptured retinal arterial macroaneurysms (RAMs). Methods Four eyes of four patients with ruptured RAMs were prospectively studied. Vascular imaging was obtained using swept-source Doppler OCT, and compared with indocyanine green angiography images. Results En face projection of Doppler OCT images clearly showed RAMs at the corresponding locations of lesions in the indocyanine green angiography images. In Doppler OCT images, RAMs were located in the inner retina in three eyes and in the medium layer of the retina in one eye. In one eye, detection of RAMs by standard OCT was ...

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    6. Noninvasive Vascular Imaging of Polypoidal Choroidal Vasculopathy by Doppler Optical Coherence Tomography

      Noninvasive Vascular Imaging of Polypoidal Choroidal Vasculopathy by Doppler Optical Coherence Tomography

      Purpose. To noninvasively investigate the vascular architecture of polypoidal lesions in polypoidal choroidal vasculopathy (PCV) using Doppler optical coherence tomography (OCT), and to evaluate the clinical usefulness of Doppler OCT for the assessment of therapeutic effects in PCV. Methods. Fifteen eyes of 15 patients with treatment-naïve PCV were prospectively studied. Vascular imaging was obtained using 1060-nm swept-source Doppler OCT, and compared with indocyanine green angiography (ICGA) images. The therapeutic effect of three consecutive intravitreal aflibercept injections was evaluated with ICGA and Doppler OCT. Results. In Doppler OCT images, polypoidal lesions were clearly detected at the corresponding locations of lesions ...

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    7. Doppler Optical Coherence Tomography Imaging of Feeder Vessels in Exudative Macular Disease

      Doppler Optical Coherence Tomography Imaging of Feeder Vessels in Exudative Macular Disease

      We evaluated the three-dimensional vascular architecture of feeder vessels in exudative macular disease. A case of polypoidal choroidal vasculopathy with choroidal neovascularization was examined with Doppler optical coherence tomography (OCT), and the three-dimensional architecture of the feeder vessels could be clearly visualized in the Doppler OCT angiography image, showing the site of growth of the feeder vessels passing through Bruch’s membrane. Together, the results demonstrated in this case report that Doppler OCT was useful for the noninvasive assessment of feeder vessels in exudative macular disease.

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    8. Three-Dimensional Vascular Imaging of Proliferative Diabetic Retinopathy by Doppler Optical Coherence Tomography

      Three-Dimensional Vascular Imaging of Proliferative Diabetic Retinopathy by Doppler Optical Coherence Tomography

      Purpose To evaluate the three-dimensional architecture of neovascularization in proliferative diabetic retinopathy using Doppler optical coherence tomography (OCT). Design Prospective, nonrandomized clinical trial. Methods Seventeen eyes of 14 patients with proliferative diabetic retinopathy were prospectively studied. Prototype Doppler OCT was used to evaluate the three-dimensional vascular architecture at vitreoretinal adhesions. Results Proliferative membranes were detected in all eyes with proliferative diabetic retinopathy by standard OCT images. Doppler OCT images detected blood flow by neovascularization of the disc in 12 eyes and neovascularization elsewhere in 11 eyes. Doppler OCT images showed the three-dimensional extent of new vessels at various stages of ...

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    9. Simultaneous Investigation of Vascular and Retinal Pigment Epithelial Pathologies of Exudative Macular Diseases by Multi-Functional Optical Coherence Tomography

      Simultaneous Investigation of Vascular and Retinal Pigment Epithelial Pathologies of Exudative Macular Diseases by Multi-Functional Optical Coherence Tomography

      Purpose: To investigate exudative macular disease, multi-functional optical coherence tomography (MF-OCT) using a 1-μm probe band was developed. The clinical utility of MF-OCT was examined in a descriptive case series. Methods: Ten eyes of nine subjects with exudative macular disease, including one eye with age-related macular degeneration (AMD), one eye with idiopathic neovascular maculopathy, and eight eyes with polypoidal choroidal vasculopathy (PCV), were investigated. Areas of 6 × 6 mm 2 around the pathologic region were scanned with 512 × 1024 depth scans in 6.6 seconds. Structural OCT, Doppler optical coherence angiography (OCA) and cumulative phase retardation images were obtained ...

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    10. Noninvasive Investigation of Deep Vascular Pathologies of Exudative Macular Diseases by High Penetration Optical Coherence Angiography

      Noninvasive Investigation of Deep Vascular Pathologies of Exudative Macular Diseases by High Penetration Optical Coherence Angiography

      Purpose: A newly developed high-penetration Doppler optical coherence angiography (HP-OCA) with a 1-μm probe beam for non-invasive investigation of vascular pathology of exudative macular diseases is introduced. A descriptive case series is presented to discuss the clinical utility of HP-OCA. Methods: Eleven eyes of 10 subjects with exudative macular disease, including 2 eyes with myopic choroidal neovascularization (mCNV), 4 eyes with age-related macular degeneration (AMD) and 5 eyes with polypoidal choroidal vasculopathy (PCV), were investigated. Two Doppler scanning modes (bi-directional and high-sensitive) of HP-OCA were used for the investigation. HP-OCA provides depth resolved and en face angiograms and a ...

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    11. An approach to measure blood flow in single choroidal vessel using Doppler optical coherence tomography

      An approach to measure blood flow in single choroidal vessel using Doppler optical coherence tomography

      Purpose:To evaluate the absolute blood flow rate in a single choroidal vessel using Doppler optical coherence tomography (OCT). Methods:Three choroidal vessels were selected in the right eye of three normal subjects, and were measured with Doppler OCT at a 1,020-nm probe wavelength. The pulsatile change of the blood flow was obtained from synchronized measurement of Doppler OCT and plethysmography. Absolute blood flow rates in choroidal vessels were calculated from Doppler OCT volume data. Results:The cyclic change of the blood flow was quantitatively obtained. Absolute blood flow velocities and blood flow rates at peak systole [mean (SD ...

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    12. High-Penetration Optical Coherence Tomography With Enhanced Depth Imaging of Polypoidal Choroidal Vasculopathy

      High-Penetration Optical Coherence Tomography With Enhanced Depth Imaging of Polypoidal Choroidal Vasculopathy

      Please wait Close Window A combination of high-penetration spectral-domain optical coherence tomography (central wavelength: 1,020 nm) and an enhanced depth imaging protocol (HP-EDI-OCT) was used to evaluate 5 eyes of 5 patients with polypoidal choroidal vasculopathy (PCV). In all eyes, HP-EDI-OCT provided high-contrast images of PCV lesions in the subretinal pigment epithelium (sub-RPE). In the space between the RPE line and Bruch’s membrane, various PCV lesions, including vascular networks, polypoidal lesions, and sub-RPE hemorrhage, were clearly identified. The chorioscleral interface was clearly observed, and the entire structure of the choroid was readily identified. Thus, HP-EDI-OCT was useful for ...

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    13. Choroidal thickness measurement in healthy Japanese subjects by three-dimensional high-penetration optical coherence tomography

      Choroidal thickness measurement in healthy Japanese subjects by three-dimensional high-penetration optical coherence tomography

      Background We performed retinal and choroidal thickness mapping by three-dimensional high-penetration optical coherence tomography (OCT) and evaluated the choroidal thickness distribution throughout the macula in healthy eyes. Methods Forty-three eyes of 43 healthy Japanese volunteers were evaluated by 1060-nm swept-source OCT. The eyes were scanned with a three-dimensional raster scanning protocol, and the mean retinal and choroidal thicknesses of the posterior sectors were obtained. The sectors were defined by the Early Treatment Diabetic Study (ETDRS) layout. These data were compared by age (23–56 years), spherical equivalent refractive error (between +0.9 D and −10.3 D), and axial length ...

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    14. Three-dimensional visualization of ocular vascular pathology by optical coherence angiography in vivo

      Three-dimensional visualization of ocular vascular pathology by optical coherence angiography in vivo
      Purpose: To demonstrate the clinical application of a noninvasive, three-dimensional vascular-imaging technique called “Doppler optical coherence angiography (OCA)”. To evaluate the vascular architecture of polypoidal choroidal vasculopathy (PCV) using Doppler OCA. Methods: We prospectively examined the eyes of 4 healthy subjects and 15 PCV patients. Three-dimensional vascular-flow imaging was performed using high-speed, high-resolution, and high-penetration spectral-domain Doppler optical coherence tomography. Two-dimensional images of the retina, choroid, and vascular lesions were obtained simultaneously. Results: Distribution of blood flow detected by Doppler OCA imaging corresponded well with that by indocyanine angiographic imaging. PCV lesions were localized in the space between the retinal ...
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    15. Polarization-Sensitive Optical Coherence Tomography of Necrotizing Scleritis

      A polarization-sensitive swept-source optical coherence tomography system (central wavelength: 1,310 nm; A-line rate: 20 kHz) was developed to evaluate the three-dimensional structure of the anterior eye segment with the phase retardation associated with the anterior segment birefringence of the eyes. Evaluation of normal eyes and an eye with necrotizing scleritis was performed. In the sclera of the normal eyes, a striking polarization change was observed in the cumulative phase retardation images and the boundary of the sclera could be readily detected. In the eye with necrotizing scleritis, phase retardation at the sclera was low in an extensive area; this ...
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    16. Three-Dimensional Optical Coherence Tomography-Guided Phototherapeutic Keratectomy for Granular Corneal Dystrophy

      Purpose: To describe the potential use of three-dimensional optical coherence tomography (OCT)-guided phototherapeutic keratectomy (PTK) for granular corneal dystrophy. Design: Investigative case report. Methods: Three-dimensional volume data of 1310-nm high-speed swept-source OCT was used to simulate the effect of PTK performed for the removal of corneal opacity in a patient with granular corneal dystrophy. Results: The OCT projection view was used to visualize the reduction of the area of the opacity with progressively deeper simulated ablation to determine the appropriate ablation depth. The results of the actual PTK corresponded well with the preoperative evaluation data. Conclusion: Three-dimensional OCT allows ...

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    17. Visualization of Sub-retinal Pigment Epithelium Morphologies of Exudative Macular Diseases by High-Penetration Optical Coherence Tomography

      PURPOSE. To evaluate the clinical significance of the newly developed long-wavelength probe optical coherence tomography (LP-OCT) for the diagnosis of exudative macular diseases. METHODS. Fourteen eyes of 13 participants were prospectively enrolled in the study. There were seven type I and five type II choroidal neovascularization (CNV) cases associated with age-related macular degeneration and idiopathic neovascularization and one case of polypoidal choroidal vasculopathy (PCV). A custom-built LP-OCT based on swept-source OCT (SS-OCT) technology was used. This new OCT uses a probe beam with a wavelength of 1060 nm that provides deeper penetration into the choroid and higher image contrast to ...
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    18. Imaging Polarimetry in Age-Related Macular Degeneration

      purpose. To evaluate the birefringence properties of eyes with age-related macular degeneration (AMD). To compare the information from two techniques—scanning laser polarimetry (GDx) and polarization-sensitive spectral-domain optical coherence tomography (OCT)—and investigate how they complement each other. methods. The authors prospectively examined the eyes of two healthy subjects and 13 patients with exudative AMD. Using scanning laser polarimetry, they computed phase-retardation maps, average reflectance images, and depolarized light images. To obtain polarimetry information with improved axial resolution, they developed a fiber-based, polarization-sensitive, spectral-domain OCT system and measured the phase retardation associated with birefringence in the same eyes. results. Both ...
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    1-18 of 18
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    Three-dimensional visualization of ocular vascular pathology by optical coherence angiography in vivo Choroidal thickness measurement in healthy Japanese subjects by three-dimensional high-penetration optical coherence tomography High-Penetration Optical Coherence Tomography With Enhanced Depth Imaging of Polypoidal Choroidal Vasculopathy An approach to measure blood flow in single choroidal vessel using Doppler optical coherence tomography Noninvasive Investigation of Deep Vascular Pathologies of Exudative Macular Diseases by High Penetration Optical Coherence Angiography Three-Dimensional Vascular Imaging of Proliferative Diabetic Retinopathy by Doppler Optical Coherence Tomography Comparison of Anterior Segment Measurements with a New Multifunctional Unit and Five Other Devices Efficacy of Notal Vision Home OCT demonstrated by a series of scientific and clinical work Synergy Between morpHOlogical and inflammatoRy Evaluation in Predicting Long-term Coronary Plaque Progression Altered ocular microvasculature in patients with systemic sclerosis and very early disease of systemic sclerosis using optical coherence tomography angiography Assessment of macular findings by OCT angiography in patients without clinical signs of diabetic retinopathy: radiomics features for early screening of diabetic retinopathy Self-Examination Low-Cost Full-Field Optical Coherence Tomography (SELFF-OCT) for neovascular age-related macular degeneration: a cross-sectional diagnostic accuracy study