著者

Ju Myeong Jin Hong Young-Joo Makita Shuichi Lim Yiheng Kurokawa Kazuhiro Duan Lian Miura Masahiro Tang Shuo Yasuno Yoshiaki

出版者

Optical Society of America

雑誌

Optics Express (ISSN:10944087)

巻号頁・発行日

vol.21, no.16, pp.19412-19436, 2013-08

被引用文献数

95

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An advanced version of Jones matrix optical coherence tomography (JMT) is demonstrated for Doppler and polarization sensitive imaging of the posterior eye. JMT is capable of providing localized flow tomography by Doppler detection and investigating the birefringence property of tissue through a three-dimensional (3-D) Jones matrix measurement. Owing to an incident polarization multiplexing scheme based on passive optical components, this system is stable, safe in a clinical environment, and cost effective. Since the properties of this version of JMT provide intrinsic compensation for system imperfection, the system is easy to calibrate. Compared with the previous version of JMT, this advanced JMT achieves a sufficiently long depth measurement range for clinical cases of posterior eye disease. Furthermore, a fine spectral shift compensation method based on the cross-correlation of calibration signals was devised for stabilizing the phase of OCT, which enables a high sensitivity Doppler OCT measurement. In addition, a new theory of JMT which integrates the Jones matrix measurement, Doppler measurement, and scattering measurement is presented. This theory enables a sensitivity-enhanced scattering OCT and high-sensitivity Doppler OCT. These new features enable the application of this system to clinical cases. A healthy subject and a geographic atrophy patient were measured in vivo, and simultaneous imaging of choroidal vasculature and birefringence structures are demonstrated.

著者

Duan Lian Hong Young-Joo Yasuno Yoshiaki

出版者

Optical Society of America

雑誌

Optics Express (ISSN:10944087)

巻号頁・発行日

vol.21, no.13, pp.15787-15808, 2013-06

被引用文献数

25

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An automated choroidal vessel segmentation and quantification method for high-penetration optical coherence tomography (OCT) was developed for advanced visualization and evaluation of the choroidal vasculature. This method uses scattering OCT volumes for the segmentation of choroidal vessels by using a multi-scale adaptive threshold. The segmented choroidal vessels are then processed by multi-scale morphological analysis to quantify the vessel diameters. The three-dimensional structure and the diameter distribution of the choroidal vasculature were then obtained. The usefulness of the method was then evaluated by analyzing the OCT volumes of normal subjects.

著者

Min Eun Jung Shin Jun Geun Lee Jae Hwi Yasuno Yoshiaki Lee Byeong Ha

出版者

Optical Society of America

雑誌

Applied optics (ISSN:1559128X)

巻号頁・発行日

vol.52, no.21, pp.5143-5151, 2013-07

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We propose a single-step method appropriated for a fiber-optic probe-based full-range spectral domain optical coherence tomography (OCT). The fiber-optic probe was scanned over a sample with a magnetically driven actuator. In the reference arm, a phase shift of π/2 was applied during two neighbor axial scanning, from which the complex spectral interferogram was directly reconstructed. Since the complex-conjugate-free OCT image is obtained by doing just one Fourier transform on the complex interferogram, obtaining the full-range image is simple in algorithm and effective in computation time. Some full-range images of biological samples created with the proposed method are presented and the processing time is analyzed.

著者

Nagase Satoko Yamanari Masahiro Tanaka Ryosuke Yasui Takeshi Miura Masahiro Iwasaki Takuya Goto Hiroshi Yasuno Yoshiaki

出版者

Public Library of Science

雑誌

PLoS ONE (ISSN:19326203)

巻号頁・発行日

vol.8, no.3, pp.e58716, 2013-03

被引用文献数

13 5

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PurposeTo investigate the relationship between scleral mechanical properties, its birefringence, and the anisotropy of birefringence alteration in respect of the direction of the strain by using PS-OCT.MethodsThe scleral birefringence of thirty-nine porcine eyes was measured with a prototype PS-OCT. A rectangle strip of sclera with a width of 4 mm was dissected at the temporal region 5 mm apart from the optic nerve head. The strain and force were measured with a uniaxial tension tester as the sample was stretched with a speed of 1.8 mm/min after preconditioning. The birefringence of the sample was measured by PS-OCT at the center of the sample before applying, denoted as inherent birefringence, and after applying stretching of 6.5% strain. The birefringence alteration was obtained by these two measurements and correlations between birefringence and elastic parameters, tangent modulus, and structural stiffness were examined. Twenty and 19 porcine eyes were stretched in meridional or equatorial directions, respectively.ResultsA moderate positive correlation was found between the inherent birefringence and the structural stiffness. A moderate positive correlation was also found between the inherent birefringence and the tangent modulus. The birefringence increased by strains. Marginal significance was found in the birefringence alteration between meridional and equatorial strains, where the mean birefringence elevation by meridional strain was higher than that by equatorial strain.ConclusionsThe birefringence was found to be altered by applying strain and also be related with inherent birefringence. This implies the birefringence of the sclera of the in vivo eye also could be affected by its mechanical property.Citation: Nagase S, Yamanari M, Tanaka R, Yasui T, Miura M, et al. (2013) Anisotropic Alteration of Scleral Birefringence to Uniaxial Mechanical Strain. PLoS ONE 8(3): e58716. doi:10.1371/journal.pone.0058716Editor: Laurent Kreplak, Dalhousie University, CanadaReceived: October 30, 2012; Accepted: February 5, 2013; Published: March 11, 2013Copyright: © 2013 Nagase et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Funding: Financial support for this study was provided in part by Japan Science Technology Agency. YY had financial interest in Tomey Corp. MY is an employee of Tomey Corp. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Competing interests: The authors have read the journal's policy and have the following conflicts: Yasuno and Yamanari are supported by a research grant from Tomey Corp. through their institution. Yamanari is now employee of Tomey Corporation. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials.

著者

Sasaki Kazuhiro Kurokawa Kazuhiro Makita Shuichi Yasuno Yoshiaki

出版者

Optical Society of America

雑誌

Biomedical Optics Express (ISSN:21567085)

巻号頁・発行日

vol.3, no.10, pp.2353-2370, 2012-10

被引用文献数

31 6

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We present an adaptive optics spectral domain optical coherence tomography (AO-SDOCT) with a long focal range by active phase modulation of the pupil. A long focal range is achieved by introducing AO-controlled third-order spherical aberration (SA). The property of SA and its effects on focal range are investigated in detail using the Huygens-Fresnel principle, beam profile measurement and OCT imaging of a phantom. The results indicate that the focal range is extended by applying SA, and the direction of extension can be controlled by the sign of applied SA. Finally, we demonstrated in vivo human retinal imaging by altering the applied SA.

著者

Jaillon Franck Makita Shuichi Yasuno Yoshiaki

出版者

Optical Society of America

雑誌

Optics Express (ISSN:10944087)

巻号頁・発行日

vol.20, no.1, pp.385-396, 2012-01

被引用文献数

24 13

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In this study, we present dual-beam Doppler optical coherence angiography with variable beam separation. Altering beam distance, independently of the scanning protocol, provides a flexible way to select the velocity range of detectable blood flow. This system utilized a one-micrometer wavelength light source to visualize deep into the posterior eye, i.e., the choroid. Two-dimensional choroidal vasculature maps of a human subject acquired with different beam separations, and hence with several velocity ranges, are presented. Combining these maps yields a semi-quantitative visualization of axial velocity of the choroidal circulation. The proposed technique may be useful for identifying choroidal abnormalities that occur in pathological conditions of the eye.

著者

Hong Young-Joo Makita Shuichi Jaillon Franck Ju Myeong Jin Min Eun Jung Lee Byeong Ha Itoh Masahide Miura Masahiro Yasuno Yoshiaki

出版者

Optical Society of America

雑誌

Optics Express (ISSN:10944087)

巻号頁・発行日

vol.20, no.3, pp.2740-2760, 2012-01

被引用文献数

50

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A high-penetration swept-source optical coherence tomography (HP-SS-OCT) system based on a 1-μm short cavity laser is developed. Doppler OCT processing is applied, along with a custom-made numerical phase stabilization algorithm; this process does not require additional calibration hardware. Thus, our phase stabilization method is simple and can be employed in a variety of SS-OCT systems. The bidirectional blood flow and vasculature in the deep choroid was successfully imaged via two Doppler modes that use different time intervals for Doppler processing. En face projection image of squared power of Doppler shift is compared to ICGA, and the utility of our method is verified.

著者

Makita Shuichi Jaillon Franck Yamanari Masahiro Yasuno Yoshiaki

出版者

Optical Society of America

雑誌

Optics Express (ISSN:10944087)

巻号頁・発行日

vol.30, no.2, pp.2681-2692, 2012-01

被引用文献数

6 3

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Dual-beam-scan Doppler optical coherence angiography (DB-OCA) enables high-speed, high-sensitivity blood flow imaging. However, birefringence of biological tissues is an obstacle to vasculature imaging. Here, the influence of polarization and birefringence on DB-OCA imaging was analyzed. A DB-OCA system without birefringence artifact has been developed by introducing a Faraday rotator. The performance was confirmed in vitro using chicken muscle and in vivo using the human eye. Birefringence artifacts due to birefringent tissues were suppressed. Micro-vasculatures in the lamina cribrosa and nerve fiber layer of human eyes were visualized in vivo. High-speed and high-sensitivity micro-vasculature imaging involving birefringent tissues is available with polarization multiplexing DB-OCA.

著者

Min Eun Jung Shin Jun Geun Lee Jae Hwi Yasuno Yoshiaki Lee Byeong Ha

出版者

Optical Society of America

雑誌

Optics letters (ISSN:01469592)

巻号頁・発行日

vol.37, no.15, pp.3105-3107, 2012-08

被引用文献数

7

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We present a full range handheld probe type spectral domain optical coherence tomography (SD-OCT) method. Here, the sample arm is composed of a tilted fiber-optic cantilever scanner; thus, the phase shift concurrently occurs while sample scanning. With the phase shift, we could achieve a full range complex-conjugate-free OCT image with no additional phase shifters in the reference arm. To realize this technique, a magnetically actuated probe was adopted. Full range SD-OCT images of a pearl, human fingernail, and human tooth were subsequently obtained using this suggested probe. The scanning range and acquisition speed were 3 mm and 20  frames/s, respectively.

著者

Yamanari Masahiro Ishii Kotaro Fukuda Shinichi Lim Yiheng Duan Lian Makita Shuichi Miura Masahiro Oshika Tetsuro Yasuno Yoshiaki

出版者

Public Library of Science

雑誌

PLoS ONE (ISSN:19326203)

巻号頁・発行日

vol.7, no.9, pp.e44026, 2012-09

被引用文献数

26 5

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PurposeTo investigate a relationship between birefringence and elasticity of porcine sclera ex vivo using polarization-sensitive optical coherence tomography (PS-OCT).MethodsElastic parameters and birefringence of 19 porcine eyes were measured. Four pieces of scleral strips which were parallel to the limbus, with a width of 4 mm, were dissected from the optic nerve head to the temporal side of each porcine eye. Birefringence of the sclera was measured with a prototype PS-OCT. The strain and force were measured with a uniaxial material tester as the sample was stretched with a speed of 1.8 mm/min after preconditioning. A derivative of the exponentially-fitted stress-strain curve at 0% strain was extracted as the tangent modulus. Power of exponential stress-strain function was also extracted from the fitting. To consider a net stiffness of sclera, structural stiffness was calculated as a product of tangent modulus and thickness. Correlations between birefringence and these elastic parameters were examined.ResultsStatistically significant correlations between birefringence and all of the elastic parameters were found at 2 central positions. Structural stiffness and power of exponential stress-strain function were correlated with birefringence at the position near the optic nerve head. No correlation was found at the position near the equator.ConclusionsThe evidence of correlations between birefringence and elasticity of sclera tested uniaxially was shown for the first time. This work may become a basis for in vivo measurement of scleral biomechanics using PS-OCT.