Abstract
Ultrabroadband sources, such as multiplexed superluminescent diodes (SLDs) and femtosecond lasers, have been successfully employed in adaptive optics optical coherence tomography (AO-OCT) systems for ultrahigh resolution retinal imaging. The large cost differential of these sources, however, motivates the need for a performance comparison. Here, we compare the performance of a Femtolasers Integral Ti:Sapphire laser and a Superlum BroadLighter T840, using the same AO-OCT system and the same subject. In addition, we investigate the capability of our instrument equipped with the Integral to capture volume images of the fovea and adjacent regions on a second subject using the AO to control focus in the retina and custom and freeware image registration software to reduce eye motion artifacts. Monochromatic ocular aberrations were corrected with a woofer-tweeter AO system. Coherence lengths of the Integral and BroadLighter were measured in vivo at 3.2 microm and 3.3 microm, respectively. The difference in dynamic range was 5 dB, close to the expected variability of the experiment. Individual cone photoreceptors, retinal capillaries and nerve fiber bundles were distinguished in all three dimensions with both sources. The acquired retinal volumes are provided for viewing in OSA ISP, allowing the reader to data mine at the microscope level.
Highlights
Optical coherence tomography (OCT), or time-domain OCT (TD-OCT), is an established noninvasive method for cross-sectional imaging the retina at high axial resolution [1]
The left plot shows the full extent of the coherence function over a ±25 μm range and reveals differences that occur in the sidelobes
The right plot shows the central core of the coherence function (±5 μm range) and reveals differences that occur in the core of the coherence function
Summary
Optical coherence tomography (OCT), or time-domain OCT (TD-OCT), is an established noninvasive method for cross-sectional imaging the retina at high axial resolution [1]. The higher resolution has enabled clear identification of the major layers of the human retina in vivo [2]. In recent years, another variant of OCT—termed spectraldomain OCT (SD-OCT)—has received considerable attention. It was discovered shortly thereafter to give a ∼100fold improvement in signal-to-noise gain over time-domain OCT [4,5,6] and could accommodate ultra-broadband sources without loss in sensitivity, both major advantages. In vivo imaging of the human retina was demonstrated at video rate with UHR-OCT, operating at an axial resolution of ∼3.5 μm [7,8]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.