Abstract
We present a novel, high-speed, polarization-sensitive, optical coherence tomography set-up for retinal imaging operating at a central wavelength of 1060 nm which was tested for in vivo imaging in healthy human volunteers. We use the system in combination with a Fourier domain mode locked laser with active spectral shaping which enables the use of forward and backward sweep in order to double the imaging speed without a buffering stage. With this approach and with a custom designed data acquisition system, we show polarization-sensitive imaging with an A-scan rate of 350 kHz. The acquired three-dimensional data sets of healthy human volunteers show different polarization characteristics in the eye, such as depolarization in the retinal pigment epithelium and birefringence in retinal nerve fiber layer and sclera. The increased speed allows imaging of large volumes with reduced motion artifacts. Moreover, averaging several two-dimensional frames allows the generation of high-definition B-scans without the use of an eye-tracking system. The increased penetration depth of the system, which is caused by the longer probing beam wavelength, is beneficial for imaging choroidal and scleral structures and allows automated segmentation of these layers based on their polarization characteristics.
Highlights
We present a high-speed swept source PS-Optical coherence tomography (OCT) system in conjunction with a broadband Fourier domain mode locked (FDML) laser operating in the 1060 nm range with 350 kHz A-scan rate
Three-dimensional and 2-D data sets of healthy human volunteers were acquired with the described polarization-sensitive OCT set-up and the described spectral shaping and imaging
The typical polarization characteristics, such as the depolarization caused by the retinal pigment ephitelium (RPE) and the birefringence of the sclera, are clearly visible in the retardation image 4(e) and the fast axis orientation image 4(g)
Summary
Optical coherence tomography (OCT) is a noninvasive imaging technique for recording high-resolution images of biological samples and has been established, in ophthalmology, as a standard tool for diagnosing ocular diseases and for monitoring therapeutic success.[1,2,3,4,5,6] The essential step, which improved the technology to a state where it gained interest for clinical use in ophthalmology, was the introduction of the spectral-domain detection principle which increased acquisition speed and sensitivity in comparison to the former time-domain technology.[7,8,9]Currently, state-of-the-art, commercially available retinal OCT scanners for clinical use work at a central wavelength of 840 nm and allow the acquisition of high depth resolution (∼5 μm) images of the ocular fundus from the inner retinal layers to the retinal pigment ephitelium (RPE) with A-scan rates beyond 20 kHz. Optical coherence tomography (OCT) is a noninvasive imaging technique for recording high-resolution images of biological samples and has been established, in ophthalmology, as a standard tool for diagnosing ocular diseases and for monitoring therapeutic success.[1,2,3,4,5,6] The essential step, which improved the technology to a state where it gained interest for clinical use in ophthalmology, was the introduction of the spectral-domain detection principle which increased acquisition speed and sensitivity in comparison to the former time-domain technology.[7,8,9]. There are three main limiting factors for extending the use of OCT for acquiring clinically relevant information with these state-of-the-art retinal OCT scanners. These limiting factors include slow acquisition speed which limits the maximum size of the volume that can be imaged with reduced motion
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
