Title: Possibility of measuring lutein in the retina by confocal micro-imaging system

Authors: Masahiro Kudo; Satoshi Wada; Takayo Ogawa; Sho Namiki; Yoko Ozawa; Kazuo Tsubota; Atsushi Shinjo; Keiji Suzuki

Addresses: Graduate School of Media and Governance, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan; Graduate School of Information Science and Technology, Hokkaido University, Kita 14, Nishi 9, Kita-ku, Sapporo Hokkaido 060-0814, Japan ' RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan ' RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan ' RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan ' Department of Ophthalmology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan ' Department of Ophthalmology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan ' Faculty of Environment and Information Studies, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan ' Graduate School of Information Science and Technology, Hokkaido University, Kita 14, Nishi 9, Kita-ku, Sapporo Hokkaido 060-0814, Japan

Abstract: The microfabrication and measurements of organic materials have significant potential for industrial and medical applications. In particular, in the medical field, a non-invasive method of measuring the distribution of certain substances contained in organic materials has been strongly demanded. Introducing a fluorescence analysis system to a confocal system would be useful for the characterisation of materials while maintaining space resolution. In this study, we focused on age-related macular degeneration (AMD) as an example, and investigated the possibility of the visualisation of fluorescence spectra. We measured the fluorescence spectrum in photoreceptor cells that were separated from the macular of eyes obtained from an eye-bank, using a microslicer. Mixed spectra of lutein and zeaxanthin, which are not affected by other organisations of eye have been measured. We also evaluated the densities of lutein and zeaxanthin in photoreceptor cells from the spectrum. As a result, the mixing ratio of lutein to zeaxanthin was estimated to be 3.78:6.22. The results showed good agreement with the results of high-performance liquid chromatography (HPLC). The approach presented here can serve as a useful framework for measuring the densities of lutein and zeaxanthin in photoreceptor cells.

Keywords: 3D microimaging; titanium sapphire lasers; preventive medicine; lutein measurement; retina; confocal microimaging; fluorescence analysis; age-related macular degeneration; AMD; visualisation; photoreceptor cells; zeaxanthin measurement.

DOI: 10.1504/IJNM.2014.062970

International Journal of Nanomanufacturing, 2014 Vol.10 No.4, pp.321 - 331

Received: 22 Nov 2012
Accepted: 02 Dec 2012
Published online: 24 Jul 2014 *

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