Wednesday, September 16, 2009

Tissue Discrimination Imaging of Anterior Eye

Our colleague Arata Miyazawa reported a new imaging methodology which used polarization sensitive optical coherence tomography (PS-OCT) and a newly developed algorithm to discriminate tissues based on their optical properties. This algorithm uses three optical properties obtained by PS-OCT including scattering intensity, signal extinction coefficient along depth, and local birefringence, and discriminates tissues based on these properties. By using this algorithm, five tissue types of an anterior eye including trabecular meshwork, conjunctiva, sclera, cornea and uvea were successfully discriminated. The details was published in Optics Express.

Citation: A. Miyazawa, M. Yamanari, S. Makita, M. Miura, K. Kawana, K. Iwaya, H. Goto, and Y. Yasuno, "Tissue discrimination in anterior eye using three optical parameters obtained by polarization sensitive optical coherence tomography, " Opt. Express 17, 17426-17440 (2009).

Friday, September 11, 2009

Ocular Biometry by 3D-OCT

Our collaborator Shinichi Fukuda investigated the utility of 3D corneal and anterior eye segment optical coherence tomography (3D-CAS-OCT) for ocular biometry. The ocular biometry is a method to extract numerical parameters from an eye, which represent the functions and integrity of the eye, e.g. a central corneal thickness (CCT) or an anterior eye chamber depth (ACD).

He examined 40 eyes of 40 normal subjects by 3D-CAS-OCT, Scheimpflug camera, scanning-slit topography and ultrasonic pachymetry, and obtained CCT, ACD and other parameters. This study indicated 3D-CAS-OCT was usable for ocular biometry.

This study has been reported on a journal Ophthalmology. The paper and abstract is available on the following locations.

>> Journal web site
>> Request reprint via e-mail (please indicate the following citation in the e-mail.)

Citation: S. Fukuda, K. Kawana, Y. Yasuno and T. Oshika, "Anterior ocular biometry using 3-dimensional optical coherence tomography," Ophthalmology 116, 882-889 (2009).

3D Investigation of Glaucoma Surgery

Keisuke Kawana has reported 3D tomographic investigation of trabeculectomy blebs. The bleb is an artificial structure created on the anterior eye by a surgery "trabeculectomy" which is for the treatment of glaucoma. He employed 3D swept-source OCT for this investigation. Internal outflow channels and scleral flaps were successfully visualized.

This report has been published in Opthalmology, and available from the following links.
>> Request reprint via e-mail. (Please copy and past the following citation.)

Citation: K. Kawana, T. Kiuchi, Y. Yasuno and T. Oshika, "Evaluation of trabeculectomy blebs using 3-dimensional cornea and anterior segment optical coherence tomography," Ophthalmology 116, 848-855 (2009).

Monday, September 7, 2009

Publication: OCT guided surgery of cornea

Hideki Mori recently published a paper of 3D OCT guided phototherapeutic keratectomy (PTK) for the treatment of granular corneal dystrophy. In this paper, he demonstrated a simulation of laser surgery of corneal dystrophy based on 3D OCT volume. This simulation was compared to the result of real PTK surgery and they showed a good agreement.

(via e-mail. Please indicate the citation).

Citation: H. Mori, M. Miura, T. Iwasaki, H. Goto, Y. Sakurai, Y. Watanabe and Y. Yasuno, "Three-dimensional optical coherence tomography-guided phototherapeutic keratectomy for granular corneal dystrophy, " Cornea 28, 944-947 (2009).

Tuesday, September 1, 2009

New Publication: Dermal Birefringence and Skin Surface

Shingo Sakai recently published a paper "Relationship Between Dermal Birefringence and the Skin Surface Roughness of Photoaged Human Skin" in Journal of Biomedical Optics. In this paper, he showed a significant correlation between the birefringence of the upper dermal region of human skin and its surface roughness. This result suggests that solar elastosis is a major factor for the progress of wrinkles.
This paper is available on the website of Journal of Biomedical Optics.

Citation: S. Sakai, N. Nakagawa, M. Yamanari, A. Miyazawa, Y. Yasuno and M. Matsumoto, "Relationship between Dermal Birefringence and the Skin Surface Roughness of Photoaged Human Skin," J. Biomed. Opt. 14, 044032 (2009).