1. Articles from Naoyuki Maeda

    1-16 of 16
    1. Comparison of composite and segmental methods for acquiring optical axial length with swept-source optical coherence tomography

      Comparison of composite and segmental methods for acquiring optical axial length with swept-source optical coherence tomography

      This study compared the optical axial length (AL) obtained by composite and segmental methods using swept-source optical coherence tomography (SS-OCT) devices, and demonstrated its effects on the post-operative refractive errors (RE) one month after cataract surgery. Conventional AL measured with the composite method used the mean refractive index. The segmented-AL method used individual refractive indices for each ocular medium. The composite AL (24.52 ± 2.03 mm) was significantly longer ( P  < 0.001) than the segmented AL (24.49 ± 1.97 mm) among a total of 374 eyes of 374 patients. Bland–Altman analysis revealed a negative proportional bias for ...

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      Mentions: Osaka University
    2. Fourier Analysis of Corneal Irregular Astigmatism Due to the Anterior Corneal Surface in Dry Eye

      Fourier Analysis of Corneal Irregular Astigmatism Due to the Anterior Corneal Surface in Dry Eye

      Objectives: To evaluate corneal irregular astigmatism due to the anterior corneal surface using Fourier harmonic analysis with a Placido ring–based corneal topographer (Placido-based topographer) and three-dimensional anterior segment optical coherence tomography (OCT) in dry eyes. Methods: Forty-four eyes of 44 subjects with dry eye and 20 eyes of 20 normal control subjects were enrolled. Corneal topographic data were obtained using a Placido-based topographer and OCT. Dioptric data from the central 3-mm zone of the anterior corneal surface were decomposed using Fourier harmonic analysis . Spherical, regular astigmatism, and irregular astigmatism (asymmetry and higher-order irregularity) refractive error components of the cornea ...

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    3. Prediction of Postoperative Intraocular Lens Position with Angle-to-Angle Depth Using Anterior Segment Optical Coherence Tomography

      Prediction of Postoperative Intraocular Lens Position with Angle-to-Angle Depth Using Anterior Segment Optical Coherence Tomography

      Purpose To evaluate the accuracy of a new formula for predicting postoperative anterior chamber depth (ACD) with preoperative angle-to-angle (ATA) depth using anterior segment (AS) optical coherence tomography (OCT) and to compare it with established methods. Design Retrospective consecutive case series. Participants Three hundred four eyes (276 patients) implanted with acrylic intraocular lenses (IOLs) were divided randomly into a training set (152 eyes) and a validation set (152 eyes). Methods Based on the training set data, the postoperative ACD measured 1 month after surgery was analyzed via multiple linear regression analysis with 5 preoperatively measured variables: ATA depth, ATA width ...

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    4. Quantitative Evaluation of the Natural Progression of Keratoconus Using Three-Dimensional Optical Coherence Tomography

      Quantitative Evaluation of the Natural Progression of Keratoconus Using Three-Dimensional Optical Coherence Tomography

      Purpose : We quantified the chronologic progression of keratoconus using anterior segment optical coherence tomography (AS-OCT). Methods : A total of 217 eyes from 113 patients with keratoconus, keratoconus suspect, or forme fruste keratoconus were evaluated by corneal tomography using swept-source OCT. Age-dependent changes in the radius of the posterior best-fit sphere (R post ), minimum corneal thickness (T min ), and distance from the thinnest point to the corneal vertex (D min ) were examined over follow-up periods of up to 5.79 years and were analyzed using generalized estimating equation (GEE) nonlinear regression model. Results : Annual changes in R post (mean, −0.017 ...

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      Mentions: Osaka University
    5. Corneal Topographic Analysis of Patients With Mooren Ulcer Using 3-Dimensional Anterior Segment Optical Coherence Tomography

      Corneal Topographic Analysis of Patients With Mooren Ulcer Using 3-Dimensional Anterior Segment Optical Coherence Tomography

      Purpose: To investigate the corneal topography and visual function of patients with Mooren ulcer using 3-dimensional anterior segment optical coherence tomography (3-D AS-OCT). Methods: Fourteen eyes of 9 patients with Mooren ulcer were studied. Pachymetric and axial power maps were obtained by 3-D AS-OCT. The axial power maps were classified into 3 patterns by visual inspection. The distribution of the corneal dioptric power was analyzed by Fourier harmonic expansion. The magnitudes of the spherical component, asymmetry, regular astigmatism, higher-order irregularity, and radial distance from the corneal vertex to the thinnest point of the lesion were determined. Results: The axial power ...

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    6. Evaluation of corneal epithelial and stromal thickness in keratoconus using spectral-domain optical coherence tomography

      Evaluation of corneal epithelial and stromal thickness in keratoconus using spectral-domain optical coherence tomography

      Purpose We sought to assess the corneal thickness of the epithelium and stroma in keratoconic and normal eyes by spectral-domain optical coherence tomography (SD-OCT). Methods Fifty-seven keratoconic and 20 normal eyes were studied. The eyes were examined by SD-OCT, and the keratoconic eyes were subdivided into 2 groups: those showing only smooth corneal thinning and corneal protrusion on the image (KC1 group) and those showing abnormalities in the Bowman layer or in the stroma, or in both (KC2 group). The thicknesses at the corneal vertex and at the superior, inferior, nasal, and temporal cornea 1.5 mm from the corneal ...

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      Mentions: Osaka University
    7. Circle and Grid-wise Analyses of Peripapillary Nerve Fiber Layers by Spectral Domain Optical Coherence Tomography in Early Stage Glaucoma

      Circle and Grid-wise Analyses of Peripapillary Nerve Fiber Layers by Spectral Domain Optical Coherence Tomography in Early Stage Glaucoma

      PURPOSE. To study diagnostic performances of circle and grid-wise analyses of peripapillary retinal nerve fiber layer thickness (RNFLT) using spectral domain optical coherence tomography (SD-OCT) in early stage glaucoma. METHODS. Eighty-nine open-angle glaucoma (OAG) eyes (mean deviation, -2.5 ± 1.8 dB) and 89 age-matched normal eyes were studied. Peripapillary RNFLT was analyzed using SD-OCT raster scan in a 6.0 × 6.0 mm area. Averaged RNFLT was calculated over 0.1 × 0.1, 0.21 × 0.21, or 0.42 × 0.42 mm grids in the peripapillary area (grid method), or arcuate sector areas between 2.8 and 4 ...

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    8. Reproducibility of Thickness Measurements of Macular Inner Retinal Layers Using SD-OCT with or without Correction of Ocular Rotation

      Reproducibility of Thickness Measurements of Macular Inner Retinal Layers Using SD-OCT with or without Correction of Ocular Rotation

      Purpose. To evaluate the inter-visit reproducibility of spectral-domain optical coherence tomography (SD-OCT) measurement of the macular retinal nerve fiber layer thickness (mRNFLT), combined ganglion cell layer and inner plexiform layer (GCL+IPL) thickness, and ganglion cell complex (GCC) thicknesses (sum of mRNFLT and GCL+IPL thicknesses) compared with that of circumpapillary RNFLT (cpRNFLT) and the effect of ocular rotation on reproducibility. Methods. SD-OCT imaging was performed twice on different days in one eye of 58 normal subjects and 73 glaucoma patients. The reproducibility was evaluated for the entire 4.8 mm x 4.8 mm macular area and sub-areas (upper ...

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    9. Corneal Topographic Analysis by 3-Dimensional Anterior Segment Optical Coherence Tomography after Endothelial Keratoplasty

      Corneal Topographic Analysis by 3-Dimensional Anterior Segment Optical Coherence Tomography after Endothelial Keratoplasty

      Purpose: To investigate the characteristics of the corneal topography with three-dimensional (3-D) anterior segment optical coherence tomography (AS-OCT) following Descemet stripping automated endothelial keratoplasty (DSAEK). Methods: Thirty-four eyes of 33 patients following DSAEK were studied. In addition to conventional topographic maps, the elevation map of the intrastromal interface and pachymetric maps of the host and graft were obtained by corneal topographic analysis using 3-D AS-OCT. The coefficient of variation of the corneal power (CV-Pa, CV-Pp) and root mean squares of the corneal elevation (RMS-Ea, RMS-Ep) of the anterior and posterior corneal surfaces were determined. Based on the combination of the ...

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      Mentions: Osaka University
    10. Effects of Age, Sex, and Axial Length on the Three-Dimensional Profile of Normal Macular Layer Structures

      Effects of Age, Sex, and Axial Length on the Three-Dimensional Profile of Normal Macular Layer Structures
      Purpose. To identify sex-related differences and age-related changes in individual retinal layer thicknesses in a population of healthy eyes across the lifespan, using spectral domain optical coherence tomography (SD-OCT). Methods. In seven institutes in Japan, mean thicknesses of the retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), photoreceptor inner segment (IS), and photoreceptor outer segment (OS) were measured using SD-OCT with a new automated segmentation protocol in 256 healthy subjects. Results. Interoperator coefficients of variability for measurements of each layer ranged from 0 ...
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    11. Corneal topographic analysis in patients with keratoconus using 3-dimensional anterior segment optical coherence tomography

      Corneal topographic analysis in patients with keratoconus using 3-dimensional anterior segment optical coherence tomography
      Purpose To assess a new corneal topographer based on 3-dimensional anterior segment optical coherence tomography (OCT-based corneal topographer) for analyzing corneal topography in patients with keratoconus. Setting Osaka University Graduate School of Medicine, Osaka, Japan. Design Evaluation of diagnostic test or technology. Methods Keratoconic eyes and normal control eyes were assessed using a rotating Scheimpflug–based corneal topographer and an AS OCT-based corneal topographer. The OCT-based corneal topographer, a 1310 nm swept-source device, captures 8192 points during 0.34 second for 16 radial scans of the corneal topography. The success rate of precisely digitizing the corneal surfaces, patterns of the ...
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      Mentions: Osaka University
    12. Variation in Optic Nerve and Macular Structure with Age and Race with Spectral-Domain Optical Coherence Tomography

      Variation in Optic Nerve and Macular Structure with Age and Race with Spectral-Domain Optical Coherence Tomography
      Purpose: To evaluate the effects of age and race on optic disc, retinal nerve fiber layer, and macular measurements with spectral-domain optical coherence tomography (SD OCT).Design: Cross-sectional observational study.Participants: Three hundred fifty adult subjects without ocular disease.Methods: Data from SD OCT imaging of the optic nerve head, peripapillary retinal nerve fiber layer (RNFL), and macula of 632 eyes from 350 subjects without ocular disease were imaged with SD OCT. Multivariate models were used to determine the effect of age and race on quantitative measurements of optic disc, RNFL, and macula.Main Outcome Measures: Optic nerve, RNFL, and ...
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    13. Peripapillary Retinal Nerve Fiber Layer Thickness Determined by Spectral-Domain Optical Coherence Tomography in Ophthalmologically Normal Eyes

      Peripapillary Retinal Nerve Fiber Layer Thickness Determined by Spectral-Domain Optical Coherence Tomography in Ophthalmologically Normal Eyes
      Objectives  To evaluate the peripapillary distribution of retinal nerve fiber layer thickness (RNFLT) in normal eyes using spectral-domain optical coherence tomography and to study potentially related factors. Methods  In 7 institutes in Japan, RNFLT in 7 concentric peripapillary circles with diameters ranging from 2.2 to 4.0 mm were measured using spectral-domain optical coherence tomography in 251 ophthalmologically normal subjects. Multiple regression analysis for the association of RNFLT with sex, age, axial length, and disc area was performed. Results  Retinal nerve fiber layer thickness decreased linearly from 125 to 89 µm as the measurement diameter increased (P < .001, mixed linear model). Retinal nerve fiber layer thickness correlated with age in all diameters (partial correlation coefficient [PCC] = –0.40 to –0.32; P < .001) and negatively correlated with disc area in the 2 innermost circles but positively correlated in the 3 outermost circles (PCC = –0.30 to –0.22 and 0.17 to 0.20; P ≤ .005). Sex and axial length did not correlate with RNFLT (P > .08). The ...
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    14. Fundus oculi observation device, a fundus oculi image display device and a fundus oculi image display method

      Fundus oculi observation device, a fundus oculi image display device and a fundus oculi image display method
      A fundus oculi observation device comprises: a first image forming part for optically obtaining data and then forming a fluorescence image of a fundus oculi of an eye administered with a fluorescent agent in advance based on the obtained data; a second image forming part for optically obtaining data and then forming a tomographic image of the fundus oculi based on the obtained data; a display; and a controller for causing said display to display said fluorescence image formed by said first image forming part side-by-side with said tomographic image formed by said second image forming part, as well as ...
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    15. Optical Coherence Tomography for Corneal Diseases

      Optical Coherence Tomography for Corneal Diseases
      Anterior segment optical coherence tomography (OCT) is currently used for investigating the distribution of the corneal thickness, shape of the stromal interface after lamellar corneal surgery, association between host and corneal graft in keratoplasty, dimension of the anterior chamber, and lesions of the corneal diseases. In addition, the advances of OCT technology has enabled three-dimensional imaging, tissue imaging, cell imaging, and topographic analysis. In this review, examples of tissue imaging with 840-nm spectral-domain OCT, cell imaging with full-field OCT, and corneal topographic analysis with 1,310-nm swept-source OCT were introduced.
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    16. Three-dimensional Profile of Macular Retinal Thickness in Normal Japanese Eyes

      Purpose: To demonstrate the 3-dimensional macular thickness distribution in normal subjects by spectral domain optical coherence tomography (SD-OCT) and evaluate its association with sex, age, and axial length. Methods: Mean regional retinal thickness measurements on the Early Treatment Diabetic Retinopathy Study (ETDRS) layout were obtained by 3-dimensional raster scanning (6 X 6 mm) using SD-OCT in 248 normal eyes of 248 Japanese subjects. Results: Mean foveal thickness was 222 ± 19 µm; it was significantly greater in men (226 ± 19 µm) than in women (218 ± 18 µm; P = 0.002) and did not correlate with age in either sex. Mean sectorial ...
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    1-16 of 16
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    1. (11 articles) Osaka University
    2. (5 articles) Kyoto University Graduate School of Medicine
    3. (5 articles) Hitomi Saito
    4. (5 articles) Nagahisa Yoshimura
    5. (5 articles) Masanori Hangai
    6. (5 articles) Atsuo Tomidokoro
    7. (5 articles) Aiko Iwase
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    Optical Coherence Tomography for Corneal Diseases Fundus oculi observation device, a fundus oculi image display device and a fundus oculi image display method Peripapillary Retinal Nerve Fiber Layer Thickness Determined by Spectral-Domain Optical Coherence Tomography in Ophthalmologically Normal Eyes Variation in Optic Nerve and Macular Structure with Age and Race with Spectral-Domain Optical Coherence Tomography Corneal topographic analysis in patients with keratoconus using 3-dimensional anterior segment optical coherence tomography Effects of Age, Sex, and Axial Length on the Three-Dimensional Profile of Normal Macular Layer Structures Corneal Topographic Analysis by 3-Dimensional Anterior Segment Optical Coherence Tomography after Endothelial Keratoplasty Reproducibility of Thickness Measurements of Macular Inner Retinal Layers Using SD-OCT with or without Correction of Ocular Rotation Evaluation of corneal epithelial and stromal thickness in keratoconus using spectral-domain optical coherence tomography Correlation between optical coherence tomography, multifocal electroretinogram findings and visual acuity in diabetic macular edema Ciliary body length revisited by anterior segment optical coherence tomography: implications for safe access to the pars plana for intravitreal injections Evaluation of retinal vascular structure after epiretinal membrane surgery by optical coherence tomography angiography