1. Articles from Yasushi Ikuno

    1-21 of 21
    1. Parallel detection of Jones-matrix elements in polarization-sensitive optical coherence tomography

      Parallel detection of Jones-matrix elements in polarization-sensitive optical coherence tomography

      The polarization properties of a sample can be characterized using a Jones matrix. To measure the Jones matrix without assumptions of the sample, two different incident states of polarization are usually used. This requirement often causes certain drawbacks in polarization-sensitive optical coherence tomography (PS-OCT), e.g., a decrease in the effective A-scan rate or axial depth range, if a multiplexing scheme is used. Because both the A-scan rate and axial depth range are important for clinical applications, including the imaging of an anterior eye segment, a new PS-OCT method that does not have these drawbacks is desired. Here, we present ...

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    2. En face optical coherence tomography imaging of beta and gamma parapapillary atrophy in high myopia

      En face optical coherence tomography imaging of beta and gamma parapapillary atrophy in high myopia

      Objective Recent studies have suggested that optical coherence tomography (OCT)-based classification of parapapillary atrophy (PPA) may be helpful in distinguishing glaucomatous from myopic optic disc changes. However, the pathological implications of PPA may be different in highly myopic eyes that exhibit optic disc deformations distinct from low to moderate myopia. Therefore, we conducted the current study to investigate factors associated with OCT-defined PPA zones measured in en face reconstructed swept source OCT (SS OCT) images in highly myopic eyes. Design Retrospective, cross-sectional study. Participants Seventy-seven eyes of 55 subjects with high myopia (spherical equivalent refractive error ≤ -8 diopters or ...

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    3. Pixel-wise segmentation of severely pathologic retinal pigment epithelium and choroidal stroma using multi-contrast Jones matrix optical coherence tomography

      Pixel-wise segmentation of severely pathologic retinal pigment epithelium and choroidal stroma using multi-contrast Jones matrix optical coherence tomography

      Tissue segmentation of retinal optical coherence tomography (OCT) is widely used in ophthalmic diagnosis. However, its performance in severe pathologic cases is still insufficient. We propose a pixel-wise segmentation method that uses the multi-contrast measurement capability of Jones matrix OCT (JM-OCT). This method is applicable to both normal and pathologic retinal pigment epithelium (RPE) and choroidal stroma. In this method, “features,” which are sensitive to specific tissues of interest, are synthesized by combining the multi-contrast images of JM-OCT, including attenuation coefficient, degree-of-polarization-uniformity, and OCT angiography. The tissue segmentation is done by simple thresholding of the feature. Compared with conventional segmentation ...

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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. Measurements of the parapapillary atrophy zones in en face optical coherence tomography images

      Measurements of the parapapillary atrophy zones in en face optical coherence tomography images

      Objective To measure the parapapillary atrophy (PPA) area in en face images obtained with swept-source optical coherence tomography (SS-OCT), and to evaluate its relationship to glaucoma, myopia, and age in non-highly myopic subjects. Design Retrospective, cross-sectional study. Participants Fifty eyes of 30 subjects with open-angle glaucoma (G group) and forty-three eyes of 26 healthy control subjects (C group). Eyes with high myopia (spherical equivalent refractive error ≤ -8 diopters or axial length ≥ 26.5 mm) were excluded. Methods Mean age ± standard deviation was 59.9 ± 12.4 years. The beta zone and the gamma zone PPA areas were measured in en ...

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    6. Retinal Microvasculature and Visual Acuity in Eyes With Branch Retinal Vein Occlusion: Imaging Analysis by Optical Coherence Tomography Angiography

      Retinal Microvasculature and Visual Acuity in Eyes With Branch Retinal Vein Occlusion: Imaging Analysis by Optical Coherence Tomography Angiography

      Purpose : To investigate microvascular changes in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in eyes with resolved branch retinal vein occlusion (BRVO) and their association with best-corrected visual acuity (BCVA). Methods : Eighty-five eyes (82 consecutive patients) with BRVO after resolution of the macular edema were retrospectively evaluated. All patients underwent optical coherence tomography angiography (OCTA) for assessment of microvascular changes, including capillary telangiectasia, microaneurysm, and disruption of the foveal avascular zone (FAZ). The areas of vascular perfusion and FAZ in the SCP and DCP were quantitatively evaluated. Best-corrected visual acuity was measured on the same day as ...

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    7. Analysis of Peripapillary Geometric Characters in High Myopia Using Swept-Source Optical Coherence Tomography

      Analysis of Peripapillary Geometric Characters in High Myopia Using Swept-Source Optical Coherence Tomography

      Purpose : We measured the three-dimensional geometric profile around the optic nerve head (ONH) using swept-source optical coherence tomography (SS-OCT) in highly myopic eyes. Methods : We studied 114 highly myopic eyes (<−6.0 diopters [D]) of 114 patients without glaucoma. Eyes were examined using the prototype SS-OCT. The retinal pigment epithelium (RPE) and chorioscleral interface were traced, and the mean y -axis coordinates of 24 sectors were calculated in circular peripapillary (3.4-mm diameter) images. The peripapillary tilting index (PTI) was calculated by subtracting the mean y -axis coordinate of the RPE in a sector from the mean of all sectors ...

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    8. Birefringence imaging of posterior eye by multi-functional Jones matrix optical coherence tomography

      Birefringence imaging of posterior eye by multi-functional Jones matrix optical coherence tomography

      A clinical grade prototype of posterior multifunctional Jones matrix optical coherence tomography (JM-OCT) is presented. This JM-OCT visualized depth-localized birefringence in addition to conventional cumulative phase retardation imaging through local Jones matrix analysis. In addition, it simultaneously provides a sensitivity enhanced scattering OCT, a quantitative polarization uniformity contrast, and OCT-based angiography. The probe beam is at 1- μ m wavelength band. The measurement speed and the depth-resolution were 100,000 A-lines/s, and 6.6 μ m in tissue, respectively. Normal and pathologic eyes are examined and several clinical features are revealed, which includes high birefringence in the choroid and lamina cribrosa ...

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    9. Analysis of choroidal folds in acute Vogt–Koyanagi–Harada disease using high-penetration optical coherence tomography

      Analysis of choroidal folds in acute Vogt–Koyanagi–Harada disease using high-penetration optical coherence tomography

      Purpose To characterize patients with Vogt–Koyanagi–Harada (VKH) disease with choroidal folds (CFs) and determine how the foveal choroidal thickness changes after initial treatment using high-penetration optical coherence tomography (HP-OCT). Methods In this retrospective observational study, we analyzed 42 eyes of 21 patients with new-onset VKH disease to determine the demographic and clinical differences between patients with and without CFs. Results Twenty-four eyes (57.1 %) of 13 patients with VKH disease had CFs. The mean age ( p  = 0.0009) of patients with CFs was significantly higher than that of those without CFs (49.1 vs 39.4 years respectively ...

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    10. Morphological Characteristics of Macular Complications of a Dome-Shaped Macula Determined by Swept-Source Optical Coherence Tomography

      Morphological Characteristics of Macular Complications of a Dome-Shaped Macula Determined by Swept-Source Optical Coherence Tomography

      Purpose To investigate the morphological characteristics of macular complications of dome-shaped maculas using Swept-Source Optical Coherence Tomography (OCT). Design Retrospective observational case series. Methods Axial length measurements and Swept-Source OCT were performed in 49 highly myopic eyes (in five males and 30 females) with dome-shaped maculas. We classified the dome patterns and measured the central retinal thickness, central choroidal thickness, central scleral thickness and the macular bulge height, and assessed the associations of these parameters with macular complications. Results The central scleral thickness was significantly negatively correlated with age and the axial length. We classified the eyes into three groups ...

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    11. Choroidal observations in posterior scleritis using high-penetration optical coherence tomography

      Choroidal observations in posterior scleritis using high-penetration optical coherence tomography

      To investigate the choroidal morphologic changes in two patients with posterior scleritis. We used high-penetration optical coherence tomography (HP-OCT) in vivo with a long-wavelength light source (1,060 nm) to view the choroidal changes. In patient 1 with unilateral scleritis, the subfoveal choroidal thickness of the right eye was 418 μm with a serous retinal detachment (SRD) at the initial visit. The treatment regimen was prednisolone 30 mg/day, and the posterior scleritis resolved. Follow-up HP-OCT showed the following choroidal thicknesses—266 μm on day 27 with no SRD, 245 μm on day 69, and 200 μm on day 216 ...

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    12. Comparison of spectral-domain and high-penetration OCT for observing morphologic changes in age-related macular degeneration and polypoidal choroidal vasculopathy

      Comparison of spectral-domain and high-penetration OCT for observing morphologic changes in age-related macular degeneration and polypoidal choroidal vasculopathy

      Background We compared the visibility of retinal and choroidal pathologies using high-penetration optical coherence tomography (HP-OCT) with a long-wavelength light source (1,050 nm) and conventional spectral-domain OCT (SD-OCT) in age-related macular degeneration (AMD). Methods One hundred and forty-six eyes were included: 63 eyes with AMD, 79 eyes with polypoidal choroidal vasculopathy (PCV), and four eyes with retinal angiomatous proliferation. The SD-OCT and HP-OCT images were compared using the grading criteria to grade the visibility of the retinal changes, the line corresponding to the retinal pigment epithelium (RPE), and the chorioscleral interface (CSI). In 132 eyes with a pigment epithelial ...

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    13. Comparison of enhanced depth imaging and high-penetration optical coherence tomography for imaging deep optic nerve head and parapapillary structures

      Comparison of enhanced depth imaging and high-penetration optical coherence tomography for imaging deep optic nerve head and parapapillary structures

      Purpose: To evaluate and compare the abilities of enhanced depth imaging (EDI) and high-penetration optical coherence tomography (HP-OCT) to visualize the deep optic nerve head (ONH) and deep parapapillary structures. Methods: Horizontal and vertical optic nerve images were obtained using EDI-OCT and HP-OCT, during the same visit, from 24 eyes of 12 patients with glaucoma. Three graders, using a three-point grading system, independently graded the visibility of the deep ONH structures (prelaminar tissue surface, anterior laminar surface, posterior laminar border, and laminar pores) and deep parapapillary structures (intrascleral vessels, cerebrospinal fluid space, and parapapillary choroid). The differences in the visibility ...

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    14. Choroidal thinning in high myopia measured by optical coherence tomography

      Choroidal thinning in high myopia measured by optical coherence tomography

      Purpose: To investigate the rate of choroidal thinning in highly myopic eyes. Patients and methods: A retrospective observational study of 37 eyes of 26 subjects (nine males and 17 females, mean age 39.6 ± 7.7 years) with high myopia but no pathologies who had undergone spectral domain optical coherence tomography and repeated the test 1 year later (1 ± 0.25 year) at Osaka University Hospital, Osaka, Japan. Patients older than 50 years with visual acuity worse than 20/40 or with whitish chorioretinal atrophy involving the macula were excluded. Two masked raters measured the choroidal thicknesses (CTs) at the ...

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    15. 3-D Choroidal Thickness Maps from EDI-OCT in Highly Myopic Eyes

      3-D Choroidal Thickness Maps from EDI-OCT in Highly Myopic Eyes

      Purpose: Myopic chorioretinal atrophy is a debilitating condition that causes severe loss of primary vision. However, its mechanisms and pathologic course are not well understood. We performed volumetric measurements of the posterior choroid via three-dimensional analysis of the choroid in patients with high myopia to understand its structure, and we compared the measurements with those of normal subjects. Methods: Twenty-five highly myopic but otherwise normal eyes and 25 nonmyopic eyes were evaluated. Enhanced depth imaging optical coherence tomography (EDI-OCT) was performed using 20 x 20-degree raster scans consisting of 25 high-speed line scans. Three-dimensional retinal and choroidal thickness maps were ...

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    16. Choroidal observations in Vogt–Koyanagi–Harada disease using high-penetration optical coherence tomography

      Choroidal observations in Vogt–Koyanagi–Harada disease using high-penetration optical coherence tomography
      Background The aim of this work was to investigate the choroidal morphologic changes of Vogt–Koyanagi–Harada (VKH) disease in vivo using high-penetration optical coherence tomography (HP-OCT) with a long-wavelength light source (1,060 nm). Methods Fourteen patients with VKH disease were included in this study: 12 eyes of six patients with treatment-naive acute VKH in the first 6–12 months after diagnosis and 16 eyes of eight patients in the convalescent phase with a sunset glow fundus appearance. A prototype HP-OCT instrument was used to observe the deep choroid and sclera. The choroidal thickness was measured for more than ...
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    17. Evaluation of the Choroidal Thickness Using High-Penetration Optical Coherence Tomography With Long Wavelength in Highly Myopic Normal-Tension Glaucoma

      Evaluation of the Choroidal Thickness Using High-Penetration Optical Coherence Tomography With Long Wavelength in Highly Myopic Normal-Tension Glaucoma
      Purpose: To evaluate the choroidal thickness by high-penetration optical coherence tomography (OCT) using long wavelength in highly myopic normal-tension glaucoma (NTG). Design: Cross-sectional retrospective study. Methods: settings: Institutional. participants: Twelve eyes from 8 patients under 45 years old, diagnosed as NTG without any other ocular diseases, spherical equivalent refractive error between −6 and −12 diopters, and axial length greater than 26.5 mm; and 12 eyes of matched healthy volunteers. intervention: Choroid was imaged with prototype high-penetration OCT and its thickness was measured. main outcome measures: Choroidal thickness at the fovea and 5 locations: 2 mm superior, temporal, and inferior ...
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    18. Spectral-Domain Optical Coherence Tomographic Findings in Punctate Inner Choroidopathy

      Spectral-Domain Optical Coherence Tomographic Findings in Punctate Inner Choroidopathy
      Purpose: To investigate the pathology of punctate inner choroidopathy (PIC) using spectral-domain optical coherence tomography. Methods: We retrospectively reviewed spectral-domain optical coherence tomography findings of 14 cases with active PIC. We obtained specific appearance of the active PIC lesion that were characterized by yellowish/white round spots in fundus examination with fluorescein leakage. Fluorescein angiogram and confocal indocyanine green angiogram were also reviewed. Results: Three cases (21%) of 14 were found to have specific findings. Case 1 was a 33-year-old woman who showed old choroidal neovascularization and active PIC. Spectral-domain optical coherence tomography showed multiple pigment epithelial detachments with hyperreflective ...
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    19. Reproducibility of Retinal and Choroidal Thickness Measurements in Enhanced Depth Imaging and High-Penetration Optical Coherence Tomography

      Reproducibility of Retinal and Choroidal Thickness Measurements in Enhanced Depth Imaging and High-Penetration Optical Coherence Tomography
      Purpose. Two optical coherence tomography (OCT) modalities can visualize the choroid: high-penetration OCT (HP-OCT) using a long wavelength and enhanced depth imaging technique using Heidelberg OCT (EDI-OCT). The purpose of this study was to compare and investigate the agreement among the retinal/choroidal thickness parameters. Methods. Twenty-four eyes of 12 healthy volunteers were examined simultaneously using the prototype swept-source HP-OCT and EDI-OCT. Six independent examiners measured the central retinal/choroidal thicknesses on horizontal B-scan images. The reliability was evaluated by intra-class correlation coefficient (ICC). Inter-visit reproducibility was assessed by examining 10 of the volunteers 4 months later. Results. Using HP-OCT ...
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    20. Spectral-Domain Optical Coherence Tomographic Findings in Myopic Foveoschisis

      Purpose: The purpose of this study was to investigate the sensitivity of various scan modes of spectral-domain optical coherence tomography (SD-OCT) for detecting pathologies that may accompany myopic foveoschisis, which is important for making surgical decisions and planning surgical strategies for myopic foveoschisis. Methods: Twenty-one eyes of 18 patients were diagnosed with myopic foveoschisis by SD-OCT. Patients were examined with SD-OCT using both a five-line raster scan and a three-dimensional scan at the same visit. The detection rates of pathologies such as macular hole, epiretinal membrane, retinal vascular microfolds, internal limiting membrane detachment, paravascular microhole, and photoreceptor inner and outer ...
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    21. Retinal and choroidal biometry in highly myopic eyes using spectral-domain optical coherence tomography

      Purpose: Morphologic changes of the retina and choroid are closely related with high myopia-related pathologies. We evaluated the morphologic characteristics of normal highly myopic eyes. Patients and methods: Thirty-one phakic highly myopic eyes with no posterior abnormalities in 18 patients (mean+/-SD age 51.7+/-11.4 y) were enrolled. Retinal/choroidal thickness at the fovea 1.5 mm superiorly, inferiorly, nasally, and temporally, and the choroidal curvature were measured in the 512x128 3D scan mode with spectral domain optical coherence tomography. Degree of posterior staphyloma was determined as the sum of the vertical distance from the retinal pigment epithelial ...
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    1-21 of 21
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    1. (21 articles) Yasushi Ikuno
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    Reproducibility of Retinal and Choroidal Thickness Measurements in Enhanced Depth Imaging and High-Penetration Optical Coherence Tomography Spectral-Domain Optical Coherence Tomographic Findings in Punctate Inner Choroidopathy Evaluation of the Choroidal Thickness Using High-Penetration Optical Coherence Tomography With Long Wavelength in Highly Myopic Normal-Tension Glaucoma Choroidal observations in Vogt–Koyanagi–Harada disease using high-penetration optical coherence tomography 3-D Choroidal Thickness Maps from EDI-OCT in Highly Myopic Eyes Comparison of spectral-domain and high-penetration OCT for observing morphologic changes in age-related macular degeneration and polypoidal choroidal vasculopathy Morphological Characteristics of Macular Complications of a Dome-Shaped Macula Determined by Swept-Source Optical Coherence Tomography Birefringence imaging of posterior eye by multi-functional Jones matrix optical coherence tomography In vivo evaluation of corneal biomechanical properties by optical coherence elastography at different cross-linking irradiances The Association of Optical Coherence Tomography Results With Neuroimaging Signs and Some Clinical Parameters in Idiopathic Intracranial Hypertension Low cost scalable monolithic common path probe design for the application in endoscopic optical coherence tomography Retinal and Choroidal Vascular Changes in Eyes with Pseudoexfoliation Syndrome: a Comparative Study Using Optical Coherence Tomography Angiography