Thursday, October 18, 2012

Visualization of Choriocapillaris by Doppler OCT

Our colleague Kazuhiro Kurokawa reported in vivo imaging of choriocapillaris by using Doppler optical coherence tomography (Doppler OCT) equipped with adaptive optics (AO) retinal scanner. Doppler OCT have been long time utilized for the investigation of retinal vasculature. Despite of its high ability for the visualization of vasculature, it was not possible to visualize choriocapillaris mainly because of its very small dimensions. We overcame this issue by using a custom made AO retinal scanner.
      The details are presented in our recent paper in Optics Express.

>> Full length article (open access)
Citation: K. Kurokawa, K. Sasaki, S. Makita, Y.-J. Hong, and Y. Yasuno, "Three-dimensional retinal and choroidal capillary imaging by power Doppler optical coherence angiography with adaptive optics," Opt. Express 20, 22796-22812 (2012).

Scleral biomechanics and birefringence

Our colleague Masahiro Yamanari recently reported a new method for noninvasive assessment of scleral biomechanics. The biomechanics of sclera is supported by its micro-structure that is mainly formed by collagen fibers. Since the collagen fibers is known to have strong form birefringence, we may be able to assess the biomechanics by measuring the birefringence. Yamanari demonstrated significant correlation between the scleral mechanical stiffness and its birefringence which was measured by a polarization sensitive optical coherence tomography.
      You can find more details in our article on PLoS ONE.

>> Full length article on journal web site (open access)
Citation: M. Yamanari, K. Ishii, S. Fukuda, Y.H. Lim, S. Makita, M. Miura, T. Oshika, and Y. Yasuno, "Optical rheology of porcine sclera by birefringence imaging," PLoS ONE 7, e44026 (2012).

Joschi, Yoshiaki Yasuno

Quantifying Blood Flow in Choroid

Figure Miura 2012 IOVS.Our colleague Masahiro Miura from Tokyo Medical University recently reported our first trial of quantification of choroidal blood flow. He utilized a custom made Doppler optical coherence tomography with a probe beam at 1.0-um band. The Doppler signal at the choroid was further processed with a structural structural information of the vessel. Finally an absolute velocities of choroidal blood flow in in vivo human eyes were presented.
     The details are presented in a recent issue of Investigative Ophthalmology and Visual Science.

>> Abstract and full length article on the journal web-site

Citation: M. Miura, S. Makita, T. Iwasaki, Y. Yasuno, "An approach to measure blood flow in single choroidal vessel using Doppler optical coherence tomography," Invest. Ophthalmol. Vis. Sci. 53, 7137-7141 (2012).