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 implementations of 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.

© 2011 OSA

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. D. T. Miller, D. Williams, G. Morris, and J. Liang, “Images of cone photoreceptors in the living human eye,” Vision Res.36, 1067–1079 (1996).
    [CrossRef] [PubMed]
  2. J. Liang, D. R. Williams, and D. T. Miller, “Supernormal vision and high-resolution retinal imaging through adaptive optics,” J. Opt. Soc. Am. A14, 2884–2892 (1997).
    [CrossRef]
  3. D. Williams, “Imaging single cells in the living retina.” Vision Res. (2011).
    [CrossRef] [PubMed]
  4. E. Fernández, B. Povazay, B. Hermann, A. Unterhuber, H. Sattmann, P. Prieto, R. Leitgeb, P. Ahnelt, P. Artal, and W. Drexler, “Three-dimensional adaptive optics ultrahigh-resolution optical coherence tomography using a liquid crystal spatial light modulator,” Vision Res.45, 3432–3444 (2005).
    [CrossRef] [PubMed]
  5. Y. Zhang, J. Rha, R. S. Jonnal, and D. T. Miller, “Adaptive optics parallel spectral domain optical coherence tomography for imaging the living retina,” Opt. Express13, 4792–4811 (2005).
    [CrossRef] [PubMed]
  6. R. Zawadzki, S. Jones, S. Olivier, M. Zhao, B. Bower, J. Izatt, S. Choi, S. Laut, and J. Werner, “Adaptive-optics optical coherence tomography for high-resolution and high-speed 3d retinal in vivo imaging,” Opt. Express13, 8532–8546 (2005).
    [CrossRef] [PubMed]
  7. Y. Zhang, B. Cense, J. Rha, R. S. Jonnal, W. Gao, R. J. Zawadzki, J. S. Werner, S. Jones, S. Olivier, and D. T. Miller, “High-speed volumetric imaging of cone photoreceptors with adaptive optics spectral-domain optical coherence tomography,” Opt. Express14, 4380–4394 (2006).
    [CrossRef] [PubMed]
  8. R. Zawadzki, B. Cense, Y. Zhang, S. Choi, D. Miller, and J. Werner, “Ultrahigh-resolution optical coherence tomography with monochromatic and chromatic aberration correction,” Opt. Express16, 8126–8143 (2008).
    [CrossRef] [PubMed]
  9. E. Fernández, B. Hermann, B. Považay, A. Unterhuber, H. Sattmann, B. Hofer, P. Ahnelt, and W. Drexler, “Ultra-high resolution optical coherence tomography and pancorrection for cellular imaging of the living human retina,” Opt. Express16, 11083–11094 (2008).
    [CrossRef] [PubMed]
  10. W. Gao, Y. Zhang, B. Cense, R. S. Jonnal, J. Rha, and D. Miller, “Measuring retinal contributions to the optical Stiles-Crawford effect with optical coherence tomography,” Opt. Express16, 6486–501 (2008).
    [CrossRef] [PubMed]
  11. M. Pircher, E. Götzinger, O. Findl, S. Michels, W. Geitzenauer, C. Leydolt, U. Schmidt-Erfurth, and C. Hitzenberger, “Human macula investigated in vivo with polarization-sensitive optical coherence tomography,” Invest. Ophth. Vis. Sci.47, 5487 (2006).
    [CrossRef]
  12. B. Cense, W. Gao, J. M. Brown, S. M. Jones, R. S. Jonnal, M. Mujat, B. H. Park, J. F. de Boer, and D. T. Miller, “Retinal imaging with polarization-sensitive optical coherence tomography and adaptive optics,” Opt. Express17, 21634–21651 (2009).
    [CrossRef] [PubMed]
  13. O. P. Kocaoglu, S. Lee, R. S. Jonnal, Q. Wang, A. E. Herde, J. C. Derby, W. Gao, and D. T. Miller, “Imaging cone photoreceptors in three dimensions and in time using ultrahigh resolution optical coherence tomography with adaptive optics,” Biomed. Opt. Express2, 748–763 (2011).
    [CrossRef] [PubMed]
  14. R. S. Jonnal, J. Rha, Y. Zhang, B. Cense, W. Gao, and D. T. Miller, “In vivo functional imaging of human cone photoreceptors,” Opt. Express15, 16141–16160 (2007).
    [CrossRef] [PubMed]
  15. R. S. Jonnal, J. R. Besecker, J. C. Derby, O. P. Kocaoglu, B. Cense, W. Gao, Q. Wang, and D. T. Miller, “Imaging outer segment renewal in living human cone photoreceptors,” Opt. Express18, 5257–5270 (2010).
    [CrossRef] [PubMed]
  16. M. Pircher, J. Kroisamer, F. Felberer, H. Sattmann, E. Götzinger, and C. Hitzenberger, “Temporal changes of human cone photoreceptors observed in vivo with slo/oct,” Biomed. Opt. Express2, 100–112 (2011).
    [CrossRef] [PubMed]
  17. O. P. Kocaoglu, S. Lee, R. S. Jonnal, Q. Wang, A. E. Herde, J. R. Besecker, W. Gao, and D. T. Miller, “3D imaging of cone photoreceptors over extended time periods using optical coherence tomography with adaptive optics,” Proc. SPIE7885, 78850C (2011),.
    [CrossRef]
  18. T. Akkin, D. P. Davé, T. E. Milner, and H. G. Rylander, “Detection of neural activity using phase-sensitive optical low-coherence reflectometry,” Opt. Express12, 2377–2386 (2004).
    [CrossRef] [PubMed]
  19. M. Choma, A. Ellerbee, C. Yang, T. Creazzo, and J. Izatt, “Spectral-domain phase microscopy,” Opt. Lett.30, 1162–1164 (2005).
    [CrossRef] [PubMed]
  20. C. Joo, T. Akkin, B. Cense, B. Park, and J. de Boer, “Spectral-domain optical coherence phase microscopy for quantitative phase-contrast imaging,” Opt. Lett.30, 2131–2133 (2005).
    [CrossRef] [PubMed]
  21. J. Izatt, M. Kulkarni, S. Yazdanfar, J. Barton, and A. Welch, “In vivo bidirectional color doppler flow imaging of picoliter blood volumes using optical coherence tomography,” Opt. Lett.22, 1439–1441 (1997).
    [CrossRef]
  22. R. Leitgeb, L. Schmetterer, W. Drexler, A. Fercher, R. Zawadzki, and T. Bajraszewski, “Real-time assessment of retinal blood flow with ultrafast acquisition by color doppler fourier domain optical coherence tomography,” Opt. Express11, 3116–3121 (2003).
    [CrossRef] [PubMed]
  23. S. Makita, Y. Hong, M. Yamanari, T. Yatagai, and Y. Yasuno, “Optical coherence angiography,” Opt. Express14, 7821–7840 (2006).
    [CrossRef] [PubMed]
  24. B. Cense, E. Koperda, J. M. Brown, O. P. Kocaoglu, W. Gao, R. S. Jonnal, and D. T. Miller, “Volumetric retinal imaging with ultrahigh-resolution spectral-domain optical coherence tomography and adaptive optics using two broadband light sources,” Opt. Express17, 4095–4111 (2009).
    [CrossRef] [PubMed]
  25. A. Snyder, “Stiles-crawford effect-explanation and consequences,” Vision Res.13, 1115–1137 (1972).
    [CrossRef]
  26. C. Curcio, K. Sloan, R. Kalina, and A. Hendrickson, “Human photoreceptor topography.” J. Comp. Neurol.292, 497–523 (1990).
    [CrossRef] [PubMed]
  27. R. S. Jonnal, J. R. Besecker, J. C. Derby, O. P. Kocaoglu, W. Gao, and D. T. Miller, Imaging outer segment renewal in living human cone photoreceptors, presented at ARVO Annual Meeting (2010), Abstract 51:2933.
  28. D. Anderson, S. Fisher, and R. Steinberg, “Mammalian cones: disc shedding, phagocytosis, and renewal,” Invest. Ophth. Vis. Sci.17, 117–133 (1978).
  29. S. Beucher and F. Meyer, “The morphological approach to segmentation: the watershed transformation,” Opt. Eng.34, 433–433 (1992).

2011

2010

2009

2008

2007

2006

2005

2004

2003

1997

1996

D. T. Miller, D. Williams, G. Morris, and J. Liang, “Images of cone photoreceptors in the living human eye,” Vision Res.36, 1067–1079 (1996).
[CrossRef] [PubMed]

1992

S. Beucher and F. Meyer, “The morphological approach to segmentation: the watershed transformation,” Opt. Eng.34, 433–433 (1992).

1990

C. Curcio, K. Sloan, R. Kalina, and A. Hendrickson, “Human photoreceptor topography.” J. Comp. Neurol.292, 497–523 (1990).
[CrossRef] [PubMed]

1978

D. Anderson, S. Fisher, and R. Steinberg, “Mammalian cones: disc shedding, phagocytosis, and renewal,” Invest. Ophth. Vis. Sci.17, 117–133 (1978).

1972

A. Snyder, “Stiles-crawford effect-explanation and consequences,” Vision Res.13, 1115–1137 (1972).
[CrossRef]

Ahnelt, P.

E. Fernández, B. Hermann, B. Považay, A. Unterhuber, H. Sattmann, B. Hofer, P. Ahnelt, and W. Drexler, “Ultra-high resolution optical coherence tomography and pancorrection for cellular imaging of the living human retina,” Opt. Express16, 11083–11094 (2008).
[CrossRef] [PubMed]

E. Fernández, B. Povazay, B. Hermann, A. Unterhuber, H. Sattmann, P. Prieto, R. Leitgeb, P. Ahnelt, P. Artal, and W. Drexler, “Three-dimensional adaptive optics ultrahigh-resolution optical coherence tomography using a liquid crystal spatial light modulator,” Vision Res.45, 3432–3444 (2005).
[CrossRef] [PubMed]

Akkin, T.

Anderson, D.

D. Anderson, S. Fisher, and R. Steinberg, “Mammalian cones: disc shedding, phagocytosis, and renewal,” Invest. Ophth. Vis. Sci.17, 117–133 (1978).

Artal, P.

E. Fernández, B. Povazay, B. Hermann, A. Unterhuber, H. Sattmann, P. Prieto, R. Leitgeb, P. Ahnelt, P. Artal, and W. Drexler, “Three-dimensional adaptive optics ultrahigh-resolution optical coherence tomography using a liquid crystal spatial light modulator,” Vision Res.45, 3432–3444 (2005).
[CrossRef] [PubMed]

Bajraszewski, T.

Barton, J.

Besecker, J. R.

O. P. Kocaoglu, S. Lee, R. S. Jonnal, Q. Wang, A. E. Herde, J. R. Besecker, W. Gao, and D. T. Miller, “3D imaging of cone photoreceptors over extended time periods using optical coherence tomography with adaptive optics,” Proc. SPIE7885, 78850C (2011),.
[CrossRef]

R. S. Jonnal, J. R. Besecker, J. C. Derby, O. P. Kocaoglu, B. Cense, W. Gao, Q. Wang, and D. T. Miller, “Imaging outer segment renewal in living human cone photoreceptors,” Opt. Express18, 5257–5270 (2010).
[CrossRef] [PubMed]

R. S. Jonnal, J. R. Besecker, J. C. Derby, O. P. Kocaoglu, W. Gao, and D. T. Miller, Imaging outer segment renewal in living human cone photoreceptors, presented at ARVO Annual Meeting (2010), Abstract 51:2933.

Beucher, S.

S. Beucher and F. Meyer, “The morphological approach to segmentation: the watershed transformation,” Opt. Eng.34, 433–433 (1992).

Bower, B.

Brown, J. M.

Cense, B.

R. S. Jonnal, J. R. Besecker, J. C. Derby, O. P. Kocaoglu, B. Cense, W. Gao, Q. Wang, and D. T. Miller, “Imaging outer segment renewal in living human cone photoreceptors,” Opt. Express18, 5257–5270 (2010).
[CrossRef] [PubMed]

B. Cense, W. Gao, J. M. Brown, S. M. Jones, R. S. Jonnal, M. Mujat, B. H. Park, J. F. de Boer, and D. T. Miller, “Retinal imaging with polarization-sensitive optical coherence tomography and adaptive optics,” Opt. Express17, 21634–21651 (2009).
[CrossRef] [PubMed]

B. Cense, E. Koperda, J. M. Brown, O. P. Kocaoglu, W. Gao, R. S. Jonnal, and D. T. Miller, “Volumetric retinal imaging with ultrahigh-resolution spectral-domain optical coherence tomography and adaptive optics using two broadband light sources,” Opt. Express17, 4095–4111 (2009).
[CrossRef] [PubMed]

W. Gao, Y. Zhang, B. Cense, R. S. Jonnal, J. Rha, and D. Miller, “Measuring retinal contributions to the optical Stiles-Crawford effect with optical coherence tomography,” Opt. Express16, 6486–501 (2008).
[CrossRef] [PubMed]

R. Zawadzki, B. Cense, Y. Zhang, S. Choi, D. Miller, and J. Werner, “Ultrahigh-resolution optical coherence tomography with monochromatic and chromatic aberration correction,” Opt. Express16, 8126–8143 (2008).
[CrossRef] [PubMed]

R. S. Jonnal, J. Rha, Y. Zhang, B. Cense, W. Gao, and D. T. Miller, “In vivo functional imaging of human cone photoreceptors,” Opt. Express15, 16141–16160 (2007).
[CrossRef] [PubMed]

Y. Zhang, B. Cense, J. Rha, R. S. Jonnal, W. Gao, R. J. Zawadzki, J. S. Werner, S. Jones, S. Olivier, and D. T. Miller, “High-speed volumetric imaging of cone photoreceptors with adaptive optics spectral-domain optical coherence tomography,” Opt. Express14, 4380–4394 (2006).
[CrossRef] [PubMed]

C. Joo, T. Akkin, B. Cense, B. Park, and J. de Boer, “Spectral-domain optical coherence phase microscopy for quantitative phase-contrast imaging,” Opt. Lett.30, 2131–2133 (2005).
[CrossRef] [PubMed]

Choi, S.

Choma, M.

Creazzo, T.

Curcio, C.

C. Curcio, K. Sloan, R. Kalina, and A. Hendrickson, “Human photoreceptor topography.” J. Comp. Neurol.292, 497–523 (1990).
[CrossRef] [PubMed]

Davé, D. P.

de Boer, J.

de Boer, J. F.

Derby, J. C.

Drexler, W.

Ellerbee, A.

Felberer, F.

Fercher, A.

Fernández, E.

E. Fernández, B. Hermann, B. Považay, A. Unterhuber, H. Sattmann, B. Hofer, P. Ahnelt, and W. Drexler, “Ultra-high resolution optical coherence tomography and pancorrection for cellular imaging of the living human retina,” Opt. Express16, 11083–11094 (2008).
[CrossRef] [PubMed]

E. Fernández, B. Povazay, B. Hermann, A. Unterhuber, H. Sattmann, P. Prieto, R. Leitgeb, P. Ahnelt, P. Artal, and W. Drexler, “Three-dimensional adaptive optics ultrahigh-resolution optical coherence tomography using a liquid crystal spatial light modulator,” Vision Res.45, 3432–3444 (2005).
[CrossRef] [PubMed]

Findl, O.

M. Pircher, E. Götzinger, O. Findl, S. Michels, W. Geitzenauer, C. Leydolt, U. Schmidt-Erfurth, and C. Hitzenberger, “Human macula investigated in vivo with polarization-sensitive optical coherence tomography,” Invest. Ophth. Vis. Sci.47, 5487 (2006).
[CrossRef]

Fisher, S.

D. Anderson, S. Fisher, and R. Steinberg, “Mammalian cones: disc shedding, phagocytosis, and renewal,” Invest. Ophth. Vis. Sci.17, 117–133 (1978).

Gao, W.

O. P. Kocaoglu, S. Lee, R. S. Jonnal, Q. Wang, A. E. Herde, J. C. Derby, W. Gao, and D. T. Miller, “Imaging cone photoreceptors in three dimensions and in time using ultrahigh resolution optical coherence tomography with adaptive optics,” Biomed. Opt. Express2, 748–763 (2011).
[CrossRef] [PubMed]

O. P. Kocaoglu, S. Lee, R. S. Jonnal, Q. Wang, A. E. Herde, J. R. Besecker, W. Gao, and D. T. Miller, “3D imaging of cone photoreceptors over extended time periods using optical coherence tomography with adaptive optics,” Proc. SPIE7885, 78850C (2011),.
[CrossRef]

R. S. Jonnal, J. R. Besecker, J. C. Derby, O. P. Kocaoglu, B. Cense, W. Gao, Q. Wang, and D. T. Miller, “Imaging outer segment renewal in living human cone photoreceptors,” Opt. Express18, 5257–5270 (2010).
[CrossRef] [PubMed]

B. Cense, W. Gao, J. M. Brown, S. M. Jones, R. S. Jonnal, M. Mujat, B. H. Park, J. F. de Boer, and D. T. Miller, “Retinal imaging with polarization-sensitive optical coherence tomography and adaptive optics,” Opt. Express17, 21634–21651 (2009).
[CrossRef] [PubMed]

B. Cense, E. Koperda, J. M. Brown, O. P. Kocaoglu, W. Gao, R. S. Jonnal, and D. T. Miller, “Volumetric retinal imaging with ultrahigh-resolution spectral-domain optical coherence tomography and adaptive optics using two broadband light sources,” Opt. Express17, 4095–4111 (2009).
[CrossRef] [PubMed]

W. Gao, Y. Zhang, B. Cense, R. S. Jonnal, J. Rha, and D. Miller, “Measuring retinal contributions to the optical Stiles-Crawford effect with optical coherence tomography,” Opt. Express16, 6486–501 (2008).
[CrossRef] [PubMed]

R. S. Jonnal, J. Rha, Y. Zhang, B. Cense, W. Gao, and D. T. Miller, “In vivo functional imaging of human cone photoreceptors,” Opt. Express15, 16141–16160 (2007).
[CrossRef] [PubMed]

Y. Zhang, B. Cense, J. Rha, R. S. Jonnal, W. Gao, R. J. Zawadzki, J. S. Werner, S. Jones, S. Olivier, and D. T. Miller, “High-speed volumetric imaging of cone photoreceptors with adaptive optics spectral-domain optical coherence tomography,” Opt. Express14, 4380–4394 (2006).
[CrossRef] [PubMed]

R. S. Jonnal, J. R. Besecker, J. C. Derby, O. P. Kocaoglu, W. Gao, and D. T. Miller, Imaging outer segment renewal in living human cone photoreceptors, presented at ARVO Annual Meeting (2010), Abstract 51:2933.

Geitzenauer, W.

M. Pircher, E. Götzinger, O. Findl, S. Michels, W. Geitzenauer, C. Leydolt, U. Schmidt-Erfurth, and C. Hitzenberger, “Human macula investigated in vivo with polarization-sensitive optical coherence tomography,” Invest. Ophth. Vis. Sci.47, 5487 (2006).
[CrossRef]

Götzinger, E.

M. Pircher, J. Kroisamer, F. Felberer, H. Sattmann, E. Götzinger, and C. Hitzenberger, “Temporal changes of human cone photoreceptors observed in vivo with slo/oct,” Biomed. Opt. Express2, 100–112 (2011).
[CrossRef] [PubMed]

M. Pircher, E. Götzinger, O. Findl, S. Michels, W. Geitzenauer, C. Leydolt, U. Schmidt-Erfurth, and C. Hitzenberger, “Human macula investigated in vivo with polarization-sensitive optical coherence tomography,” Invest. Ophth. Vis. Sci.47, 5487 (2006).
[CrossRef]

Hendrickson, A.

C. Curcio, K. Sloan, R. Kalina, and A. Hendrickson, “Human photoreceptor topography.” J. Comp. Neurol.292, 497–523 (1990).
[CrossRef] [PubMed]

Herde, A. E.

O. P. Kocaoglu, S. Lee, R. S. Jonnal, Q. Wang, A. E. Herde, J. C. Derby, W. Gao, and D. T. Miller, “Imaging cone photoreceptors in three dimensions and in time using ultrahigh resolution optical coherence tomography with adaptive optics,” Biomed. Opt. Express2, 748–763 (2011).
[CrossRef] [PubMed]

O. P. Kocaoglu, S. Lee, R. S. Jonnal, Q. Wang, A. E. Herde, J. R. Besecker, W. Gao, and D. T. Miller, “3D imaging of cone photoreceptors over extended time periods using optical coherence tomography with adaptive optics,” Proc. SPIE7885, 78850C (2011),.
[CrossRef]

Hermann, B.

E. Fernández, B. Hermann, B. Považay, A. Unterhuber, H. Sattmann, B. Hofer, P. Ahnelt, and W. Drexler, “Ultra-high resolution optical coherence tomography and pancorrection for cellular imaging of the living human retina,” Opt. Express16, 11083–11094 (2008).
[CrossRef] [PubMed]

E. Fernández, B. Povazay, B. Hermann, A. Unterhuber, H. Sattmann, P. Prieto, R. Leitgeb, P. Ahnelt, P. Artal, and W. Drexler, “Three-dimensional adaptive optics ultrahigh-resolution optical coherence tomography using a liquid crystal spatial light modulator,” Vision Res.45, 3432–3444 (2005).
[CrossRef] [PubMed]

Hitzenberger, C.

M. Pircher, J. Kroisamer, F. Felberer, H. Sattmann, E. Götzinger, and C. Hitzenberger, “Temporal changes of human cone photoreceptors observed in vivo with slo/oct,” Biomed. Opt. Express2, 100–112 (2011).
[CrossRef] [PubMed]

M. Pircher, E. Götzinger, O. Findl, S. Michels, W. Geitzenauer, C. Leydolt, U. Schmidt-Erfurth, and C. Hitzenberger, “Human macula investigated in vivo with polarization-sensitive optical coherence tomography,” Invest. Ophth. Vis. Sci.47, 5487 (2006).
[CrossRef]

Hofer, B.

Hong, Y.

Izatt, J.

Jones, S.

Jones, S. M.

Jonnal, R. S.

O. P. Kocaoglu, S. Lee, R. S. Jonnal, Q. Wang, A. E. Herde, J. R. Besecker, W. Gao, and D. T. Miller, “3D imaging of cone photoreceptors over extended time periods using optical coherence tomography with adaptive optics,” Proc. SPIE7885, 78850C (2011),.
[CrossRef]

O. P. Kocaoglu, S. Lee, R. S. Jonnal, Q. Wang, A. E. Herde, J. C. Derby, W. Gao, and D. T. Miller, “Imaging cone photoreceptors in three dimensions and in time using ultrahigh resolution optical coherence tomography with adaptive optics,” Biomed. Opt. Express2, 748–763 (2011).
[CrossRef] [PubMed]

R. S. Jonnal, J. R. Besecker, J. C. Derby, O. P. Kocaoglu, B. Cense, W. Gao, Q. Wang, and D. T. Miller, “Imaging outer segment renewal in living human cone photoreceptors,” Opt. Express18, 5257–5270 (2010).
[CrossRef] [PubMed]

B. Cense, W. Gao, J. M. Brown, S. M. Jones, R. S. Jonnal, M. Mujat, B. H. Park, J. F. de Boer, and D. T. Miller, “Retinal imaging with polarization-sensitive optical coherence tomography and adaptive optics,” Opt. Express17, 21634–21651 (2009).
[CrossRef] [PubMed]

B. Cense, E. Koperda, J. M. Brown, O. P. Kocaoglu, W. Gao, R. S. Jonnal, and D. T. Miller, “Volumetric retinal imaging with ultrahigh-resolution spectral-domain optical coherence tomography and adaptive optics using two broadband light sources,” Opt. Express17, 4095–4111 (2009).
[CrossRef] [PubMed]

W. Gao, Y. Zhang, B. Cense, R. S. Jonnal, J. Rha, and D. Miller, “Measuring retinal contributions to the optical Stiles-Crawford effect with optical coherence tomography,” Opt. Express16, 6486–501 (2008).
[CrossRef] [PubMed]

R. S. Jonnal, J. Rha, Y. Zhang, B. Cense, W. Gao, and D. T. Miller, “In vivo functional imaging of human cone photoreceptors,” Opt. Express15, 16141–16160 (2007).
[CrossRef] [PubMed]

Y. Zhang, B. Cense, J. Rha, R. S. Jonnal, W. Gao, R. J. Zawadzki, J. S. Werner, S. Jones, S. Olivier, and D. T. Miller, “High-speed volumetric imaging of cone photoreceptors with adaptive optics spectral-domain optical coherence tomography,” Opt. Express14, 4380–4394 (2006).
[CrossRef] [PubMed]

Y. Zhang, J. Rha, R. S. Jonnal, and D. T. Miller, “Adaptive optics parallel spectral domain optical coherence tomography for imaging the living retina,” Opt. Express13, 4792–4811 (2005).
[CrossRef] [PubMed]

R. S. Jonnal, J. R. Besecker, J. C. Derby, O. P. Kocaoglu, W. Gao, and D. T. Miller, Imaging outer segment renewal in living human cone photoreceptors, presented at ARVO Annual Meeting (2010), Abstract 51:2933.

Joo, C.

Kalina, R.

C. Curcio, K. Sloan, R. Kalina, and A. Hendrickson, “Human photoreceptor topography.” J. Comp. Neurol.292, 497–523 (1990).
[CrossRef] [PubMed]

Kocaoglu, O. P.

Koperda, E.

Kroisamer, J.

Kulkarni, M.

Laut, S.

Lee, S.

O. P. Kocaoglu, S. Lee, R. S. Jonnal, Q. Wang, A. E. Herde, J. R. Besecker, W. Gao, and D. T. Miller, “3D imaging of cone photoreceptors over extended time periods using optical coherence tomography with adaptive optics,” Proc. SPIE7885, 78850C (2011),.
[CrossRef]

O. P. Kocaoglu, S. Lee, R. S. Jonnal, Q. Wang, A. E. Herde, J. C. Derby, W. Gao, and D. T. Miller, “Imaging cone photoreceptors in three dimensions and in time using ultrahigh resolution optical coherence tomography with adaptive optics,” Biomed. Opt. Express2, 748–763 (2011).
[CrossRef] [PubMed]

Leitgeb, R.

E. Fernández, B. Povazay, B. Hermann, A. Unterhuber, H. Sattmann, P. Prieto, R. Leitgeb, P. Ahnelt, P. Artal, and W. Drexler, “Three-dimensional adaptive optics ultrahigh-resolution optical coherence tomography using a liquid crystal spatial light modulator,” Vision Res.45, 3432–3444 (2005).
[CrossRef] [PubMed]

R. Leitgeb, L. Schmetterer, W. Drexler, A. Fercher, R. Zawadzki, and T. Bajraszewski, “Real-time assessment of retinal blood flow with ultrafast acquisition by color doppler fourier domain optical coherence tomography,” Opt. Express11, 3116–3121 (2003).
[CrossRef] [PubMed]

Leydolt, C.

M. Pircher, E. Götzinger, O. Findl, S. Michels, W. Geitzenauer, C. Leydolt, U. Schmidt-Erfurth, and C. Hitzenberger, “Human macula investigated in vivo with polarization-sensitive optical coherence tomography,” Invest. Ophth. Vis. Sci.47, 5487 (2006).
[CrossRef]

Liang, J.

J. Liang, D. R. Williams, and D. T. Miller, “Supernormal vision and high-resolution retinal imaging through adaptive optics,” J. Opt. Soc. Am. A14, 2884–2892 (1997).
[CrossRef]

D. T. Miller, D. Williams, G. Morris, and J. Liang, “Images of cone photoreceptors in the living human eye,” Vision Res.36, 1067–1079 (1996).
[CrossRef] [PubMed]

Makita, S.

Meyer, F.

S. Beucher and F. Meyer, “The morphological approach to segmentation: the watershed transformation,” Opt. Eng.34, 433–433 (1992).

Michels, S.

M. Pircher, E. Götzinger, O. Findl, S. Michels, W. Geitzenauer, C. Leydolt, U. Schmidt-Erfurth, and C. Hitzenberger, “Human macula investigated in vivo with polarization-sensitive optical coherence tomography,” Invest. Ophth. Vis. Sci.47, 5487 (2006).
[CrossRef]

Miller, D.

Miller, D. T.

O. P. Kocaoglu, S. Lee, R. S. Jonnal, Q. Wang, A. E. Herde, J. R. Besecker, W. Gao, and D. T. Miller, “3D imaging of cone photoreceptors over extended time periods using optical coherence tomography with adaptive optics,” Proc. SPIE7885, 78850C (2011),.
[CrossRef]

O. P. Kocaoglu, S. Lee, R. S. Jonnal, Q. Wang, A. E. Herde, J. C. Derby, W. Gao, and D. T. Miller, “Imaging cone photoreceptors in three dimensions and in time using ultrahigh resolution optical coherence tomography with adaptive optics,” Biomed. Opt. Express2, 748–763 (2011).
[CrossRef] [PubMed]

R. S. Jonnal, J. R. Besecker, J. C. Derby, O. P. Kocaoglu, B. Cense, W. Gao, Q. Wang, and D. T. Miller, “Imaging outer segment renewal in living human cone photoreceptors,” Opt. Express18, 5257–5270 (2010).
[CrossRef] [PubMed]

B. Cense, W. Gao, J. M. Brown, S. M. Jones, R. S. Jonnal, M. Mujat, B. H. Park, J. F. de Boer, and D. T. Miller, “Retinal imaging with polarization-sensitive optical coherence tomography and adaptive optics,” Opt. Express17, 21634–21651 (2009).
[CrossRef] [PubMed]

B. Cense, E. Koperda, J. M. Brown, O. P. Kocaoglu, W. Gao, R. S. Jonnal, and D. T. Miller, “Volumetric retinal imaging with ultrahigh-resolution spectral-domain optical coherence tomography and adaptive optics using two broadband light sources,” Opt. Express17, 4095–4111 (2009).
[CrossRef] [PubMed]

R. S. Jonnal, J. Rha, Y. Zhang, B. Cense, W. Gao, and D. T. Miller, “In vivo functional imaging of human cone photoreceptors,” Opt. Express15, 16141–16160 (2007).
[CrossRef] [PubMed]

Y. Zhang, B. Cense, J. Rha, R. S. Jonnal, W. Gao, R. J. Zawadzki, J. S. Werner, S. Jones, S. Olivier, and D. T. Miller, “High-speed volumetric imaging of cone photoreceptors with adaptive optics spectral-domain optical coherence tomography,” Opt. Express14, 4380–4394 (2006).
[CrossRef] [PubMed]

Y. Zhang, J. Rha, R. S. Jonnal, and D. T. Miller, “Adaptive optics parallel spectral domain optical coherence tomography for imaging the living retina,” Opt. Express13, 4792–4811 (2005).
[CrossRef] [PubMed]

J. Liang, D. R. Williams, and D. T. Miller, “Supernormal vision and high-resolution retinal imaging through adaptive optics,” J. Opt. Soc. Am. A14, 2884–2892 (1997).
[CrossRef]

D. T. Miller, D. Williams, G. Morris, and J. Liang, “Images of cone photoreceptors in the living human eye,” Vision Res.36, 1067–1079 (1996).
[CrossRef] [PubMed]

R. S. Jonnal, J. R. Besecker, J. C. Derby, O. P. Kocaoglu, W. Gao, and D. T. Miller, Imaging outer segment renewal in living human cone photoreceptors, presented at ARVO Annual Meeting (2010), Abstract 51:2933.

Milner, T. E.

Morris, G.

D. T. Miller, D. Williams, G. Morris, and J. Liang, “Images of cone photoreceptors in the living human eye,” Vision Res.36, 1067–1079 (1996).
[CrossRef] [PubMed]

Mujat, M.

Olivier, S.

Park, B.

Park, B. H.

Pircher, M.

M. Pircher, J. Kroisamer, F. Felberer, H. Sattmann, E. Götzinger, and C. Hitzenberger, “Temporal changes of human cone photoreceptors observed in vivo with slo/oct,” Biomed. Opt. Express2, 100–112 (2011).
[CrossRef] [PubMed]

M. Pircher, E. Götzinger, O. Findl, S. Michels, W. Geitzenauer, C. Leydolt, U. Schmidt-Erfurth, and C. Hitzenberger, “Human macula investigated in vivo with polarization-sensitive optical coherence tomography,” Invest. Ophth. Vis. Sci.47, 5487 (2006).
[CrossRef]

Povazay, B.

E. Fernández, B. Povazay, B. Hermann, A. Unterhuber, H. Sattmann, P. Prieto, R. Leitgeb, P. Ahnelt, P. Artal, and W. Drexler, “Three-dimensional adaptive optics ultrahigh-resolution optical coherence tomography using a liquid crystal spatial light modulator,” Vision Res.45, 3432–3444 (2005).
[CrossRef] [PubMed]

Považay, B.

Prieto, P.

E. Fernández, B. Povazay, B. Hermann, A. Unterhuber, H. Sattmann, P. Prieto, R. Leitgeb, P. Ahnelt, P. Artal, and W. Drexler, “Three-dimensional adaptive optics ultrahigh-resolution optical coherence tomography using a liquid crystal spatial light modulator,” Vision Res.45, 3432–3444 (2005).
[CrossRef] [PubMed]

Rha, J.

Rylander, H. G.

Sattmann, H.

Schmetterer, L.

Schmidt-Erfurth, U.

M. Pircher, E. Götzinger, O. Findl, S. Michels, W. Geitzenauer, C. Leydolt, U. Schmidt-Erfurth, and C. Hitzenberger, “Human macula investigated in vivo with polarization-sensitive optical coherence tomography,” Invest. Ophth. Vis. Sci.47, 5487 (2006).
[CrossRef]

Sloan, K.

C. Curcio, K. Sloan, R. Kalina, and A. Hendrickson, “Human photoreceptor topography.” J. Comp. Neurol.292, 497–523 (1990).
[CrossRef] [PubMed]

Snyder, A.

A. Snyder, “Stiles-crawford effect-explanation and consequences,” Vision Res.13, 1115–1137 (1972).
[CrossRef]

Steinberg, R.

D. Anderson, S. Fisher, and R. Steinberg, “Mammalian cones: disc shedding, phagocytosis, and renewal,” Invest. Ophth. Vis. Sci.17, 117–133 (1978).

Unterhuber, A.

E. Fernández, B. Hermann, B. Považay, A. Unterhuber, H. Sattmann, B. Hofer, P. Ahnelt, and W. Drexler, “Ultra-high resolution optical coherence tomography and pancorrection for cellular imaging of the living human retina,” Opt. Express16, 11083–11094 (2008).
[CrossRef] [PubMed]

E. Fernández, B. Povazay, B. Hermann, A. Unterhuber, H. Sattmann, P. Prieto, R. Leitgeb, P. Ahnelt, P. Artal, and W. Drexler, “Three-dimensional adaptive optics ultrahigh-resolution optical coherence tomography using a liquid crystal spatial light modulator,” Vision Res.45, 3432–3444 (2005).
[CrossRef] [PubMed]

Wang, Q.

Welch, A.

Werner, J.

Werner, J. S.

Williams, D.

D. T. Miller, D. Williams, G. Morris, and J. Liang, “Images of cone photoreceptors in the living human eye,” Vision Res.36, 1067–1079 (1996).
[CrossRef] [PubMed]

D. Williams, “Imaging single cells in the living retina.” Vision Res. (2011).
[CrossRef] [PubMed]

Williams, D. R.

Yamanari, M.

Yang, C.

Yasuno, Y.

Yatagai, T.

Yazdanfar, S.

Zawadzki, R.

Zawadzki, R. J.

Zhang, Y.

Zhao, M.

Biomed. Opt. Express

Invest. Ophth. Vis. Sci.

M. Pircher, E. Götzinger, O. Findl, S. Michels, W. Geitzenauer, C. Leydolt, U. Schmidt-Erfurth, and C. Hitzenberger, “Human macula investigated in vivo with polarization-sensitive optical coherence tomography,” Invest. Ophth. Vis. Sci.47, 5487 (2006).
[CrossRef]

D. Anderson, S. Fisher, and R. Steinberg, “Mammalian cones: disc shedding, phagocytosis, and renewal,” Invest. Ophth. Vis. Sci.17, 117–133 (1978).

J. Comp. Neurol.

C. Curcio, K. Sloan, R. Kalina, and A. Hendrickson, “Human photoreceptor topography.” J. Comp. Neurol.292, 497–523 (1990).
[CrossRef] [PubMed]

J. Opt. Soc. Am. A

Opt. Eng.

S. Beucher and F. Meyer, “The morphological approach to segmentation: the watershed transformation,” Opt. Eng.34, 433–433 (1992).

Opt. Express

R. Zawadzki, S. Jones, S. Olivier, M. Zhao, B. Bower, J. Izatt, S. Choi, S. Laut, and J. Werner, “Adaptive-optics optical coherence tomography for high-resolution and high-speed 3d retinal in vivo imaging,” Opt. Express13, 8532–8546 (2005).
[CrossRef] [PubMed]

Y. Zhang, B. Cense, J. Rha, R. S. Jonnal, W. Gao, R. J. Zawadzki, J. S. Werner, S. Jones, S. Olivier, and D. T. Miller, “High-speed volumetric imaging of cone photoreceptors with adaptive optics spectral-domain optical coherence tomography,” Opt. Express14, 4380–4394 (2006).
[CrossRef] [PubMed]

S. Makita, Y. Hong, M. Yamanari, T. Yatagai, and Y. Yasuno, “Optical coherence angiography,” Opt. Express14, 7821–7840 (2006).
[CrossRef] [PubMed]

R. S. Jonnal, J. Rha, Y. Zhang, B. Cense, W. Gao, and D. T. Miller, “In vivo functional imaging of human cone photoreceptors,” Opt. Express15, 16141–16160 (2007).
[CrossRef] [PubMed]

W. Gao, Y. Zhang, B. Cense, R. S. Jonnal, J. Rha, and D. Miller, “Measuring retinal contributions to the optical Stiles-Crawford effect with optical coherence tomography,” Opt. Express16, 6486–501 (2008).
[CrossRef] [PubMed]

R. Zawadzki, B. Cense, Y. Zhang, S. Choi, D. Miller, and J. Werner, “Ultrahigh-resolution optical coherence tomography with monochromatic and chromatic aberration correction,” Opt. Express16, 8126–8143 (2008).
[CrossRef] [PubMed]

E. Fernández, B. Hermann, B. Považay, A. Unterhuber, H. Sattmann, B. Hofer, P. Ahnelt, and W. Drexler, “Ultra-high resolution optical coherence tomography and pancorrection for cellular imaging of the living human retina,” Opt. Express16, 11083–11094 (2008).
[CrossRef] [PubMed]

B. Cense, E. Koperda, J. M. Brown, O. P. Kocaoglu, W. Gao, R. S. Jonnal, and D. T. Miller, “Volumetric retinal imaging with ultrahigh-resolution spectral-domain optical coherence tomography and adaptive optics using two broadband light sources,” Opt. Express17, 4095–4111 (2009).
[CrossRef] [PubMed]

B. Cense, W. Gao, J. M. Brown, S. M. Jones, R. S. Jonnal, M. Mujat, B. H. Park, J. F. de Boer, and D. T. Miller, “Retinal imaging with polarization-sensitive optical coherence tomography and adaptive optics,” Opt. Express17, 21634–21651 (2009).
[CrossRef] [PubMed]

R. S. Jonnal, J. R. Besecker, J. C. Derby, O. P. Kocaoglu, B. Cense, W. Gao, Q. Wang, and D. T. Miller, “Imaging outer segment renewal in living human cone photoreceptors,” Opt. Express18, 5257–5270 (2010).
[CrossRef] [PubMed]

R. Leitgeb, L. Schmetterer, W. Drexler, A. Fercher, R. Zawadzki, and T. Bajraszewski, “Real-time assessment of retinal blood flow with ultrafast acquisition by color doppler fourier domain optical coherence tomography,” Opt. Express11, 3116–3121 (2003).
[CrossRef] [PubMed]

T. Akkin, D. P. Davé, T. E. Milner, and H. G. Rylander, “Detection of neural activity using phase-sensitive optical low-coherence reflectometry,” Opt. Express12, 2377–2386 (2004).
[CrossRef] [PubMed]

Y. Zhang, J. Rha, R. S. Jonnal, and D. T. Miller, “Adaptive optics parallel spectral domain optical coherence tomography for imaging the living retina,” Opt. Express13, 4792–4811 (2005).
[CrossRef] [PubMed]

Opt. Lett.

Proc. SPIE

O. P. Kocaoglu, S. Lee, R. S. Jonnal, Q. Wang, A. E. Herde, J. R. Besecker, W. Gao, and D. T. Miller, “3D imaging of cone photoreceptors over extended time periods using optical coherence tomography with adaptive optics,” Proc. SPIE7885, 78850C (2011),.
[CrossRef]

Vision Res.

A. Snyder, “Stiles-crawford effect-explanation and consequences,” Vision Res.13, 1115–1137 (1972).
[CrossRef]

E. Fernández, B. Povazay, B. Hermann, A. Unterhuber, H. Sattmann, P. Prieto, R. Leitgeb, P. Ahnelt, P. Artal, and W. Drexler, “Three-dimensional adaptive optics ultrahigh-resolution optical coherence tomography using a liquid crystal spatial light modulator,” Vision Res.45, 3432–3444 (2005).
[CrossRef] [PubMed]

D. T. Miller, D. Williams, G. Morris, and J. Liang, “Images of cone photoreceptors in the living human eye,” Vision Res.36, 1067–1079 (1996).
[CrossRef] [PubMed]

Other

R. S. Jonnal, J. R. Besecker, J. C. Derby, O. P. Kocaoglu, W. Gao, and D. T. Miller, Imaging outer segment renewal in living human cone photoreceptors, presented at ARVO Annual Meeting (2010), Abstract 51:2933.

D. Williams, “Imaging single cells in the living retina.” Vision Res. (2011).
[CrossRef] [PubMed]

Supplementary Material (1)

» Media 1: AVI (5513 KB)     

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (10)

Fig. 1
Fig. 1

Conceptual diagram of OCT imaging. OCT is principally a depth imaging modality. (Left) A diagram showing the layered structure of the retina. The layers pertinent to the present work are the external limiting membrane (ELM), inner segment (IS), inner segment outer segment junction (IS/OS), outer segment (OS), posterior tip of the outer segment (PT), sub-outer segment space (SOS), and retinal pigment epithelium (RPE). (Center) In SD-OCT, each exposure of the detector generates one A-line. These A-lines are assembled, along the dimension of the fast galvo scanner, into B-scans, which in turn are assembled, along the slow scan dimension, into volumetric images. (Right) After axial registration of A-lines, transverse sections of the volumetric image can be extracted, corresponding to en face views of the retina, at various depths. Shown here, for example, are such projections of the ISOS and PT layers.

Fig. 2
Fig. 2

En face projections of the cone mosaic. (Left and center) Single en face projections of the cone mosaic, produced by co-adding the segmented images of ISOS and PT from single volumes, acquired at 1.5°. A registered average (right) using the image on the left as a reference. Scale bars represent 50 μm.

Fig. 3
Fig. 3

( Media 1). Tracking intensity and phase of individual cones over time. (Upper left) An en face projection of the cone mosaic (S1), constructed by co-adding intensities of ISOS and PT pixels for each A-line in the volume. Video shows en face projections from each volume in a series collected over two hours. Colored boxes designate locations of example cones, as they are tracked through the time series. (Upper right) An en face projection of θOS, constructed as shown in Equation 1. Colored boxes designate locations of the same example cones shown in the intensity projection. Roughly circular patches of correlated phase are clearly visible in the phase projection. (Bottom) Stabilized views of the example cones shown in the en face intensity and phase projections. In each row of box pairs, the top box shows an enlarged view of the intensity projection and the bottom box shows an enlarged view of the phase projection, as indicated by the I and θ symbols at the left. In the stabilized phase projections excluded pixels are not shown; correlation among included pixels is visually apparent. In the enlarged, stabilized phase projections, many cones do not appear circular. The reasons for this are, presumably, eye motion–which often warps the image of the cone–and segmentation errors–which may cause spurious exclusion of A-lines, leading to shape irregularities and discontinuities.

Fig. 4
Fig. 4

Within-cone phase distributions (S2). (Left, scatter plot) The median-subtracted phase of each pixel in each cone. Each column of points depicts θOS within a cone. Spatial phase wrapping is evident in the cluster of points near the ±2π edges of the plot. (Left, bar graph) The marginal histogram of the distribution on left, shown in log scale. The tails of the histogram near ±2π indicate spatial phase wrapping. (Right, scatter plot) The normalized phase of each pixel in each cone, after spatial unwrapping. (Right, bar graph) The marginal histogram of the unwrapped distribution, with noticeable reduction in the tails, which indicates the effect of unwrapping. The wrapped and unwrapped standard deviations correspond to length sensitivities (σL) of 53 nm and 27 nm, respectively. μθ represents average, median-normalized phase, over all cones.

Fig. 5
Fig. 5

Autocorrelations of ISOS phase, PT phase, intensity, and θOS, from left to right; autocorrelations clipped at 0.5 to enhance visibility of correlation tails and zero crossings. The autocorrelations of absolute phase, at ISOS and PT (far left and near left) show a small correlation between neighboring pixels in the direction of the fast scan (vertical), likely due to the brief (6 – 8 μs) interval between acquisition of successive A-lines and correspondingly small amount of axial eye motion. The autocorrelation of intensity (near right) shows a central peak with concentric rings surrounding it, characteristic of the uniformly packed cone mosaic. The spacing of the rings agrees with the expected cone spacing at this eccentricity (1.5°). The autocorrelation of referenced phase, θOS (far right) has a central peak similar to that of the intensity autocorrelation, suggesting that θOS is correlated among Alines within a cone, but not with neighboring cones. These images provide confirmation of the instrument’s sensitivity to θOS. Scale bars represent 5 μm.

Fig. 6
Fig. 6

Phase sensitivity as a function of retinal eccentricity, as measured in one subject (S3). Phase sensitivity (black squares) is better near the foveal center, which may be due to structural differences among cones at different eccentricities. It is known that cone diameter increases with retinal eccentricity (see dotted red line), which may be related to the observed differences in sensitivity.

Fig. 7
Fig. 7

Representative phase changes in two single cones (S1). For each cone, the temporally wrapped data are shown in the top plot (green markers) and temporally unwrapped data shown in the bottom plot (blue markers). In the unwrapped data, linear fits were performed, and the slopes of these fits are shown, expressed as ΔθOSt and ΔLOSt. The elongation rates of these two cones, 111 nm/hr and 84 nm/hr, are within the range of our previous findings. Data were temporally unwrapped using a linear model fitting approach, described in the appendix (§A.5).

Fig. 8
Fig. 8

Frequency spectra of sin(θOS), averaged over all cones in each of the two over-hours data sets. The frequency (x) axis has been expressed in terms of rate of OS length change, using Equation 3. Peaks at approximately 150 nm/hr can be seen in both spectra. It is uncertain whether the breadth of the peaks is due to a large range of true frequencies or to fitting noise. Previous experiments [27] found a narrower range of frequencies, which suggests the breadth here may be due to fitting noise.

Fig. 9
Fig. 9

Autocorrelations of θIS (left) and θSOS (right), as compared to that of θOS (center), and profile plots below (blue). Profiles of the intensity autocorrelation (red, dashed) are superimposed on each profile, for comparison. The first zero in each profile plot can be thought of as the correlation width. For θOS, the correlation width is 5 μm. For θIS and θSOS, the correlation widths are both 4 μm. Scale bars represent 5 μm.

Fig. 10
Fig. 10

An example of spatial unwrapping and OS length-based exclusion, applied to Alines in a single cone. (Top left) En face view of a cone’s intensity, projected by summing the intensities of the ISOS and PT reflections in each A-line in an 11 × 11 μm (1 μm/px) subvolume at 1.5°, centered about the automatically identified x- and y-coordinate of the cone. The green circle indicates the cone’s region of interest (ROI), defined as all the pixels within a fixed radius of the cone center; the radius was D/2, where D is the predicted center-to-center spacing of the cones, and varied with retinal eccentricity. (Top center) OS lengths for each A-line in the ROI, determined by the automatic segmentation of retinal layers. (Top right) Indices, arbitrarily assigned, for each of the 21 pixels (A-lines) in the cone’s ROI. (Bottom left) En face projection of θOS. Each pixel is computed by applying Eqn. 1 to the complex A-lines in the subvolume. It is clear in the θOS projection that many of the pixels in the ROI have values close to 0 rad, with the exceptions of pixels 10 and 15, which have values close to 2π, and pixels 8, 14, and 19, which have values somewhere between. (Bottom center, square markers) Phase values from the ROI plotted by pixel index. This plot confirms what was visually apparent in the θOS projection, that most pixels are close to 0 rad, while two are near 2π rad and three are between π and 1.8π. From the length map (top center) it is evident that four of these pixels (8, 9, 14, and 19, specifically) do not have OS lengths matching the rest of the pixels, which suggests they should be excluded from the phase analysis. Spatial unwrapping (based on variance minimization) shifts pixels 10 and 15 by −2π. The unwrapped values are shown with blue diamonds on the plot. (Bottom right) θOS plotted from the subvolume, scaled between the minimum and maximum unwrapped θOS values.

Tables (1)

Tables Icon

Table 1 Subjects imaged in experiments, along with imaging source used. See text for details on which subjects were imaged in which experiments.

Equations (3)

Equations on this page are rendered with MathJax. Learn more.

θ OS = mod ( θ PT θ ISOS , 2 π )
σ L = σ θ λ / ( 4 π n OS ) .
Δ L OS / Δ t = Δ θ OS λ 4 π n OS 1 Δ t

Metrics