Ultrahigh Speed Imaging of the Rat Retina Using Ultrahigh
Resolution Spectral/Fourier Domain OCT
The MIT Faculty has made this article openly available. Please share
how this access benefits you. Your story matters.
Citation
Jonathan J. Liu ; Benjamin Potsaid ; Yueli Chen ; Iwona
Gorczynska ; Vivek J. Srinivasan ; Jay S. Duker ; James G.
Fujimoto; Ultrahigh-speed imaging of the rat retina using
ultrahigh-resolution spectral/Fourier domain OCT. Proc. SPIE
7550, Ophthalmic Technologies XX, 755017 (March 02, 2010).
SPIE © 2010
As Published
http://dx.doi.org/10.1117/12.842540
Publisher
SPIE
Version
Final published version
Accessed
Thu May 26 12:03:02 EDT 2016
Citable Link
http://hdl.handle.net/1721.1/73963
Terms of Use
Article is made available in accordance with the publisher's policy
and may be subject to US copyright law. Please refer to the
publisher's site for terms of use.
Detailed Terms
Ultrahigh Speed Imaging of the Rat Retina Using
Ultrahigh Resolution Spectral / Fourier Domain OCT
Jonathan J. Liu*a, Benjamin Potsaida,c, Yueli Chena,b, Iwona Gorczynskaa,b, Vivek J. Srinivasana,
Jay S. Dukerb and James G. Fujimotoa
a
Deptartment of Electrical Engineering and Computer Science and
Research Laboratory of Electronics,
Massachusetts Institute of Technology, Cambridge, MA
b
New England Eye Center, Tufts-New England Medical Center, Tufts University, Boston, MA
c
Advanced Imaging Group, Thorlabs, Inc., Newton, NJ
ABSTRACT
We performed OCT imaging of the rat retina at 70,000 axial scans per second with ~3 μm axial resolution.
Three-dimensional OCT (3D-OCT) data sets of the rat retina were acquired. The high speed and high density
data sets enable improved en face visualization by reducing eye motion artifacts and improve Doppler OCT
measurements. Minimal motion artifacts were visible and the OCT fundus images offer more precise
registration of individual OCT images to retinal fundus features. Projection OCT fundus images show
features such as the nerve fiber layer, retinal capillary networks and choroidal vasculature. Doppler OCT
images and quantitative measurements show pulsatility in retinal blood vessels. Doppler OCT provides noninvasive in vivo quantitative measurements of retinal blood flow properties and may benefit studies of
diseases such as glaucoma and diabetic retinopathy. Ultrahigh speed imaging using ultrahigh resolution
spectral / Fourier domain OCT promises to enable novel protocols for measuring small animal retinal
structure and retinal blood flow. This non-invasive imaging technology is a promising tool for monitoring
disease progression in rat and mouse models to assess ocular disease pathogenesis and response to treatment.
Keywords: Ultrahigh resolution OCT, ultrahigh speed OCT, spectral/Fourier domain OCT, Doppler OCT,
small animal imaging
* liujj@mit.edu; phone 1 617 253-8140; fax 1 617 253-9611; www.rle.mit.edu
1. INTRODUCTION
The murine retina is structurally similar to the human retina. Rat and mouse models provide powerful tools
for characterization of ocular disease pathogenesis and response to treatment. Therefore, non-invasive
imaging technologies for measuring rat and mouse retinal structure and physiology at the micron scale could
be useful tools for biomedical research on ocular disease. Spectral / Fourier domain OCT enables ultrahigh
speed and ultrahigh resolution 3D imaging or volumetric imaging [1-3], offering a promising technique for rat
and mouse retinal imaging [4].
2. MATERIALS AND METHODS
An ultrahigh resolution spectral / Fourier domain OCT prototype instrument has been developed for small
animal imaging using new, high speed CMOS imaging technology [5]. This technology can achieve imaging
speeds over 70,000 axial scans per second. Figure 1 shows the schematic of the OCT system for small animal
imaging. To achieve ultrahigh-resolutions, we used a multiplexed two-superluminescent-diode light source
(Superlum) with 145 nm bandwidth and 890 nm center wavelength. A microscope delivery system was used
Ophthalmic Technologies XX, edited by Fabrice Manns, Per G. Söderberg, Arthur Ho, Proc. of SPIE Vol. 7550,
755017 · © 2010 SPIE · CCC code: 1605-7422/10/$18 · doi: 10.1117/12.842540
Proc. of SPIE Vol. 7550 755017-1
Downloaded from SPIE Digital Library on 05 Jul 2012 to 18.51.3.76. Terms of Use: http://spiedl.org/terms
for focusing and scanning the OCT beam in the animal eye. The power at the rat eye was 1.3 mW. The
maximum sensitivity was ~94 dB. Three-dimensional OCT (3D-OCT) data sets of the rat retina were
acquired. OCT fundus images were created from 3D-OCT data. Doppler OCT analysis [6-8] of blood flow in
the rat retina was performed. The maximum measurable velocity before phase wrapping is 12 mm/s.
Figure 1. Schematic of high-speed ultrahigh resolution OCT system with a pre-objective scanning
microscope design for small animal retina imaging. Spectral / Fourier domain detection is performed
with a spectrometer and high speed CMOS camera.
3. RESULTS
OCT imaging of the rat retina was performed at 70,000 axial scans per second with ~3 µm resolution. A
standard 3D-OCT data set containing 180 images, each consisting of 512 axial scans, is acquired in ~1.4
seconds. As shown in figure 2, minimal motion artifacts are visible and the OCT fundus images offer more
precise registration of individual OCT images to retinal fundus features. Projection OCT fundus images[9] in
figure 3 show features such as the nerve fiber layer, retinal capillary networks and choroidal vasculature. In
figure 4, Doppler OCT images and quantitative measurements show pulsatility in retinal blood vessels.
Figure 2. A) Raster scan pattern shown on rat fundus photo. 3D-OCT data consisting of 512 axial
scans per frame x 180 frames covering 2 mm x 2 mm area was acquired in ~1.4 seconds. B) Standard
OCT fundus images are created by summing the signal in the axial direction, yielding an image similar
to a fundus photograph. C-F) High definition OCT images with 2048 axial scans, each acquired in 29
µs, may be registered to the OCT fundus image.
Proc. of SPIE Vol. 7550 755017-2
Downloaded from SPIE Digital Library on 05 Jul 2012 to 18.51.3.76. Terms of Use: http://spiedl.org/terms
Figure 3. OCT en face visualizations are created by summing layers sectioned at different levels in the
axial direction, providing images of selected layers of the retina. This dataset consists of 300 axial
scans per frame x 300 frames covering 1mm x 1mm area and was acquired in ~1.3 seconds.
Figure 4. A) Quantitative Doppler OCT measurement in the axial direction showing pulsatile blood
flow. (A) Pulsatile blood flow showing a heart rate of ~300 beats per minute. B, C) Doppler OCT
images over a 65 µm x 100 µm region of interest and blood flow measurements showing pulsatility
during two cardiac cycles. Repeated Doppler OCT scans with 512 axial scans over a 250 µm cross
section were continuously acquired for ~1.8 seconds.
Proc. of SPIE Vol. 7550 755017-3
Downloaded from SPIE Digital Library on 05 Jul 2012 to 18.51.3.76. Terms of Use: http://spiedl.org/terms
4. CONCLUTIONS
In conclusion, ultrahigh speed retinal imaging was demonstrated in the rat retina using ultrahigh resolution
spectral / Fourier domain OCT. 3D-OCT data sets obtained at high speed show reduced motion artifacts,
enabling improved en face OCT fundus imaging. Doppler OCT provides non-invasive in vivo quantitative
measurements of retinal blood flow properties and may benefit studies of diseases such as glaucoma and
diabetic retinopathy. Ultrahigh resolution spectral / Fourier domain OCT promises to enable novel protocols
for measuring small animal retinal structure and retinal blood flow. Furthermore, this non-invasive imaging
technology is a promising tool for monitoring disease progression in rat and mouse models to characterize
ocular disease pathogenesis and response to treatment.
Acknowledgements: Supported in part by contracts from the National Institutes of Health 5R01-EY01128923, 5R01-EY013178-09, 2R01-EY013516-16, 1R01-EY019029-01 and Air Force Office of Scientific
Research FA9550-07-1-0101, FA9550-07-1-0014.
REFERENCES
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
B. Cense, N. Nassif, T. C. Chen et al., “Ultrahigh-resolution high-speed retinal imaging using spectraldomain optical coherence tomography,” Optics Express, 12, 2435-2447 (2004).
R. A. Leitgeb, W. Drexler, A. Unterhuber et al., “Ultrahigh resolution Fourier domain optical coherence
tomography,” Optics Express, 12(10), 2156-2165 (2004).
M. Wojtkowski, V. Srinivasan, J. G. Fujimoto et al., “Three-dimensional retinal imaging with highspeed ultrahigh-resolution optical coherence tomography,” Ophthalmology, 112(10), 1734-46 (2005).
V. J. Srinivasan, T. H. Ko, M. Wojtkowski et al., “Noninvasive volumetric Imaging and morphometry
of the rodent retina with high-speed, ultrahigh-resolution optical coherence tomography,” Investigative
Ophthalmology & Visual Science, 47(12), 5522-5528 (2006).
B. Potsaid, I. Gorczynska, V. J. Srinivasan et al., “Ultrahigh speed Spectral/Fourier domain OCT
ophthalmic imaging at 70,000 to 312,500 axial scans per second,” Optics Express, 16(19), 15149-15169
(2008).
R. A. Leitgeb, L. Schmetterer, W. Drexler et al., “Real-time assessment of retinal blood flow with
ultrafast acquisition by color Doppler Fourier domain optical coherence tomography,” Optics Express,
11(23), 3116-3121 (2003).
B. R. White, M. C. Pierce, N. Nassif et al., “In vivo dynamic human retinal blood flow imaging using
ultra-high-speed spectral domain optical Doppler tomography,” Optics Express, 11(25), 3490-3497
(2003).
S. Makita, Y. Hong, M. Yamanari et al., “Optical coherence angiography,” Optics Express, 14(17),
7821-7840 (2006).
I. Gorczynska, V. J. Srinivasan, L. N. Vuong et al., “Projection OCT fundus imaging for visualizing
outer retinal pathology in non-exudative age related macular degeneration Comparison of optic disc
margin identified by color disc photography and high-speed ultrahigh-resolution optical coherence
tomography,” Br J Ophthalmol, 28(1), 28 (2008).
Proc. of SPIE Vol. 7550 755017-4
Downloaded from SPIE Digital Library on 05 Jul 2012 to 18.51.3.76. Terms of Use: http://spiedl.org/terms