New publication: 1-um polarization-sensitive SS-OCT

Our new paper about 1-um polarization-sensitive SS-OCT was published in Optics Express. Phase retardation images of sclera and lamina cribrosa in the posterior eye were visualized at 1-um wavelength for the first time. We described how the system sensitivity was optimized and how the polarization-insensitive image was important for the imaging of birefringent tissues.

The paper is available with open access in Optics Express.

Citation: Masahiro Yamanari, Yiheng Lim, Shuichi Makita, and Yoshiaki Yasuno, "Visualization of phase retardation of deep posterior eye by polarization-sensitive swept-source optical coherence tomography with 1-µm probe," Opt. Express 17, 12385-12396 (2009)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-17-15-12385

SPIE Newsroom: Multifunctional Anterior OCT

An article of our multifunctional anterior optical coherence tomography is now available on SPIE newsroom. This article for general readers may give you a quick overview of cutting-edge anterior OCT!

>>> SPEI Newsroom: Multifunctional optical imaging reveals properties of the anterior eye

Joschi

Our Ophthalmologist receives PhD of Engineering

I proudly announce that our aggressive ophthalmologist Dr. Masahiro Miura received PhD of Engineering, his second PhD,s from University of Tsukuba. The subject of his PhD was ophthalmic polarimetries in ophthalmology, which includes polarimetric scanning laser ophthalmoscope and polarization sensitive optical coherence tomography. His PhD thesis "Imaging Polarimetry of Human Eye" is available on the following link.

>> PhD thesis on Tsukuba Repository

Joschi

New publication: 3D polarization sensitive OCT of glaucoma surgery

Our new paper is now published in Optics Express. This paper presents a case series of glaucoma surgeries measured by our three-dimensional polarization sensitive optical coherence tomography (3-D PS-OCT). Since this paper is an interactive scientific publication (SIP), full 3-D PS-OCT data sets of cases is downloadable in addition to conventional static picture-figures. You can download the datasets and can write your own signal processing software.

The manuscript is freely downloadable from Optics Express web-site.

>> Article in Optics Express

Citation: Y. Yasuno, M. Yamanari, K. Kawana, T. Oshika, and M. Miura, "Investigation of post-glaucoma-surgery structures by three-dimensional and polarization sensitive anterior eye segment optical coherence tomography," Opt. Express 17, 3980-3996 (2009).

Joschi, Yoshiaki Yasuno

New Publication: Retinal Shadow Compensation in Retinal OCT

Our new paper was published in Journal of Biomedical Optics Letters (JBO). This paper describes a simple but effective numerical algorithm to remove shadowing artifacts caused by retinal vessels in an optical coherence tomography (OCT) image. The paper is published in an open access manner, and available on JBO web site.

>>> [Abstract and PDF on JBO web site]

Citation: T. Fabritius, S. Makita, Y. Hong, R. Myllyla and Y. Yasuno, "Automated retinal shadow compensation of optical coherence tomography images," J. Biomed. Opt. 14, 010503 (2009).

Kurokawa won Pascal Rol Award

Kazuhiro Kurokawa (Computational Optics Group in the University of Tsukuba) was chosen as the best presenter and received Pascal Rol Award at Photonics West in January, 2009.

Pascal Rol Award was established for the promotion of ophthalmic technologies in the memory of Pascal Rol (University Eye Clinic, Zurich). This Pascal Rol Award is given to the best presented ophthalmic engineer at Photonics West.

Kurokawa was the one who gained acceptance with his research "one-micrometer wavelength adaptive optics scanning laser opthalmoscope."

Ishii

黒川氏がPascal Rol Award受賞

先月米国にて開催されたPhotonics Westにおいて黒川和博氏（Computational Optics Group in the University of Tsukuba）が2009年のPascal Rol Awardを受賞しました。

Pascal Rol Award賞は2000年に急逝した著名な眼科光学研究者であるPascal Olivier Rol（チューリッヒ眼科大学病院、マイアミ大学）の功績を称えて設立されたものであり、Photonics Westにおいて最も優れた研究を公表した眼科工学研究者一人に贈られます。

今回はマサチューセッツ工科大学、ウィーン医科大学等からの他のノミネートを抑えて黒川氏が研究成果「1μm帯域光を利用したレーザー走査検眼鏡」を認められての受賞となりました。Computational Optics Groupでは2007年の安野嘉晃氏に続き二度目の受賞となります。

石井

New Publication: Investigation of photo-aging by PS-OCT

A new paper was published by our project of polarization sensitive optical coherence tomography (PS-OCT) and skin investigation in Journal of Investigative Dermatology (JID). In this paper, we examined photo-aged skins of young and old subjects by PS-OCT and quantitatively analyzed the skin birefringence. In this study, we found that dermal birefringence of the cheek skin, which was well exposed by sun light, was significantly smaller in the old group than in the young group. On the other hand, the interior upper arm, which was normally exposed by sun light, showed no age-dependent difference.

     The abstract and the full article are available on the journal web site and PubMed.

>>> [Article on JID site]

>>> [Abstract on PubMed]

Citation: S. Sakai, M. Yamanari, A. Miyazawa, M. Matsumoto, N. Nakagawa, T. Sugawara, K. Kawabata, T. yatagai, and Y. Yasuno, "In vivo three-dimensional birefringence analysis shows collagen differences between young and old photo-aged human skin," J. Inv. Dermatol. 128, 1641-1647 (2008).

Joschi, Yoshiaki Yasuno

Update of Publication: AMD and High-Penetration OCT

Original article is on August 13, 2008

The following our paper is now officially published in Investigative Ophthalmology and Visual Science (IOVS).

Y. Yasuno, M. Miura, K. Kawana, S. Makita, M. Sato, F. Okamoto, M. Yamanari, T. Iwasaki, T. Yatagai, and T. Oshika, "Visualization of Sub-retinal Pigment Epithelium Morphologies of Exudative Macular Diseases by High-Penetration Optical Coherence Tomography," Inv. Ophthalmol. Vis. Sci. 50, 405-513 (2009).

This paper demonstrates the application of new OCT with one-micrometer probe wavelength (high-penetration OCT; HP-OCT) to age-related macular degeneration. 14 eyes were involved in this study, and the clinical utility of HP-OCT was discussed. Preliminary results which suggest higher robustness of HP-OCT to cataract than standard OCT were also shown. The paper is available on the journal web site (IOVS).

>>> [Abstract and PDF]

New publication: AMD and High-Penetration OCT

Our new paper is now available as publish ahead of print of IOVS. This paper demonstrates the application of new OCT with 1 micrometer probe wavelength (high-penetration OCT; HP-OCT, also referred to as long probe OCT; LP-OCT) to age-related macular degeneration. 14 eyes were involved in this study, and the clinical utility of HP-OCT was discussed. Preliminary results which suggest higher robustness of HP-OCT to cataract than standard OCT were also shown. The paper is available on the journal web site (IOVS).
>>> [Abstract and PDF at IOVS web-site]

Title: Visualization of Sub-Retinal Pigment Epithelium and Sub-Choroidal Neovascularization Morphologies of Exudative Macular Diseases by Optical Coherence Tomography with Long Wavelength Probe
Authors: Y. Yasuno, M. Miura, K. Kawana, S.Makita, M. Sato, F. Okamoto, M. Yamanari, T. Iwasaki, T. Yatagai, T. Oshika
Journal: Investigative Ophthalmology & Vision Science
Volume/Page: publish ahead of print

Joschi, Yoshiaki Yasuno

講義資料： 医療機器開発と産学連携

Lecture Material: Collaboration of University and Industry for the Development of Medical Equipment
(See below for an English version)

応用理工学概論「医療機器開発と産学連携」の講義資料を公開します。いそいで作った出来の悪いマテリアルですが… 興味のある方はどうぞ。
- PDFをダウンロード

Joschi, 安野嘉晃

Here we release a Lecture Material of ``Collaboration of University and Industry for the Development of Medical Equipment.'' This material is for the lecture of``Introduction to Applied Science and Engineering,'' which is a general introduction for the 1st year students of our University (University of Tsukuba).
The material is still very primitive and written in English... But you can download it from the following URL.
- Download PDF

Joschi, Yoshiaki Yasuno

BiOS/ARVO2008 レポート (Only in Japanese)

国際会議 SPIE BiOS/Photonics West 2008, および米眼科学会 ARVO 2008 の簡易レポートを公開します。第5回電気学会バイオメディカル・フォトニクス先端技術調査専門委員会（2008年6月16日）による報告のために作成されたレポートです。興味のある方は「安野による主観的なもの」であることをご承知の上でご参考ください。

PDFをダウンロード

Joschi, 安野嘉晃

Imaging Plarimetry in Age-Related Macular Degeneration

Our new paper was published in Investigative Ophthalmology and Visual Science (IOVS).
[Download from Journal Web Site]

The details are following

Title: Imaging Polarimetry in Age-Related Macular Degeneration

Authors: Masahiro Miura, Masahiro Yamanari, Takuya Iwasaki, Ann E. Elsner, Shuichi Makita, Toyohiko Yatagai, and Yoshiaki Yasuno

Citation: Invest. Ophthalmo. Vis. Sci. 49, 2661-2667 (2008).

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 GDx and polarization-sensitive spectral-domain optical coherence tomography detected abnormal birefringence at the locus of exudative lesions. Polarization-sensitive, spectral-domain OCT showed that in the old lesions with fibrosis, phase-retardation values were significantly larger than in the new lesions (P = 0.020). Increased scattered light and altered polarization scramble were associated with portions of the lesions.

CONCLUSIONS
GDx and polarization-sensitive spectral-domain OCT are complementary in probing birefringence properties in exudative AMD. Polarimetry findings in exudative AMD emphasized different features and were related to the progression of the disease, potentially providing a noninvasive tool for microstructure in exudative AMD.

Image of the week in Optics InfoBase

The volume rendering image of the optic nerve head in our new publication entitled "Full-range, high-speed, high-resolution 1μm spectral-domain optical coherence tomography using BM-scan for volumetric imaging of the human posterior eye" was selected to "Image of the week" in Optics InfoBase.

New publication: Full-range, high-speed 1um SD-OCT

Full-range, high-speed, high-resolution 1μm spectral-domain optical coherence tomography using BM-scan for volumetric imaging of the human posterior eye

This our paper is now available on Optics Express.

>>[Abstract and PDF]

Citation
S. Makita, T. Fabritius, and Y. Yasuno, "Full-range, high-speed, high-resolution 1μm spectral-domain optical coherence tomography using BM-scan for volumetric imaging of the human posterior eye," Opt. Express 16, 8406-8420 (2008).


Abstract
An alternative optical coherence tomography (OCT) to clinical ophthalmic 830 nm spectral-domain OCTs (SD-OCT) is demonstrated. An axial resolution of 7.4 μm, ranging depth of 4.2 mm in tissue, sensitivity of 98.5 dB, and detection speed of 38,300 axial scans/s have been achieved. These are comparable or superior to those of recently commercially available ophthalmic 830 nm SD-OCTs in clinics. In addition, fast volumetric imaging for the in vivo human posterior eye with high-contrast of the choroid is achieved. A broadband 1.04 μm light source enables the high-contrast and high resolution imaging of the retina and choroid. The ranging depth is extended by applying a full-range imaging method with an electro-optic modulator (BM-scan method). A prototype high-speed InGaAs line scan camera with 1024 pixels is used. A newly reported sensitivity improvement property of the BM-scan method demonstrates a sensitivity enhancement of 5.1 dB. We also introduce a newly developed resampling calibration method of spectrum that is independent of the intrinsic dispersion mismatch of the interferometer. The three-dimensional structure of the in vivo human optic nerve head with a very deep cupping is successfully visualized.