Show simple item record Jonnal, R.S. Kocaoglu, O.P. Wang, Q. Lee, S. Miller, D.T. 2014-11-11T21:24:48Z 2014-11-11T21:24:48Z 2012
dc.identifier.citation Jonnal, R. S., Kocaoglu, O. P., Wang, Q., Lee, S., & Miller, D. T. (2012). Phase-sensitive imaging of the outer retina using optical coherence tomography and adaptive optics. Biomedical Optics Express, 3(1), 104-124. en
dc.description.abstract The cone photoreceptor's outer segment (OS) experiences changes in optical path length, both in response to visible stimuli and as a matter of its daily course of renewal and shedding. These changes are of interest, to quantify function in healthy cells and assess dysfunction in diseased ones. While optical coherence tomography (OCT), combined with adaptive optics (AO), has permitted unprecedented three-dimensional resolution in the living retina, it has not generally been able to measure these OS dynamics, whose scale is smaller than OCT's axial resolution of a few microns. A possible solution is to take advantage of the phase information encoded in the OCT signal. Phase-sensitive implementationsof spectral-domain optical coherence tomography (SD-OCT) have been demonstrated, capable of resolving sample axial displacements much smaller than the imaging wavelength, but these have been limited to ex vivo samples. In this paper we present a novel technique for retrieving phase information from OCT volumes of the outer retina. The key component of our technique is quantification of phase differences within the retina. We provide a quantitative analysis of such phase information and show that- when combined with appropriate methods for filtering and unwrapping-it can improve the sensitivity to OS length change by more than an order of magnitude, down to 45 nm, slightly thicker than a single OS disc. We further show that phase sensitivity drops off with retinal eccentricity, and that the best location for phase imaging is close to the fovea. We apply the technique to the measurement of sub-resolution changes in the OS over matters of hours. Using custom software for registration and tracking, these microscopic changes are monitored in hundreds of cones over time. In two subjects, the OS was found to have average elongation rates of 150 nm/hr, values which agree with our previous findings. en
dc.language.iso en_US en
dc.publisher The Optical Society of America en
dc.relation.isversionof en
dc.rights © 2011 Optical Society of America en
dc.subject Axial displacements en
dc.subject Axial resolutions en
dc.subject Cone photoreceptors en
dc.subject Elongation rates en
dc.subject Ex-vivo en
dc.subject Novel techniques en
dc.subject OCT signals en
dc.subject Optical path lengths en
dc.subject Outer segments en
dc.subject Phase difference en
dc.subject Phase imaging en
dc.subject Phase information en
dc.subject Phase sensitive imaging en
dc.subject Phase sensitivity en
dc.subject Phase-sensitive en
dc.subject Retinal eccentricity en
dc.subject Spectral-domain optical coherence tomography en
dc.subject Subresolution en
dc.subject Three-dimensional resolution en
dc.subject Optical constants en
dc.subject Optics en
dc.subject Optical tomography en
dc.title Phase-sensitive imaging of the outer retina using optical coherence tomography and adaptive optics en
dc.type Article en
dc.altmetrics.display true en

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