June 2017
Volume 58, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2017
Polarization-multiplexed, dual-beam swept source optical coherence tomography angiography
Author Affiliations & Notes
  • Jianlong Yang
    Casey Eye Institute, Oregon Health & Science Univeristy, Portland, Oregon, United States
  • Yali Jia
    Casey Eye Institute, Oregon Health & Science Univeristy, Portland, Oregon, United States
  • David Huang
    Casey Eye Institute, Oregon Health & Science Univeristy, Portland, Oregon, United States
  • Gangjun Liu
    Casey Eye Institute, Oregon Health & Science Univeristy, Portland, Oregon, United States
  • Footnotes
    Commercial Relationships   Jianlong Yang, None; Yali Jia, Optovue, Inc. (P); David Huang, Carl Zeiss Meditec (P), Optovue, Inc. (P); Gangjun Liu, None
  • Footnotes
    Support  This research was funded by Oregon Health & Science Foundation, National Institutes of Health Grants DP3 DK104397, R01 EY024544, R01 EY023285 and R01 EY018184, unrestricted departmental funding from Research to Prevent Blindness (New York, NY), and P30 EY010572 from the National Institutes of Health (Bethesda, MD).
Investigative Ophthalmology & Visual Science June 2017, Vol.58, 3811. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Jianlong Yang, Yali Jia, David Huang, Gangjun Liu; Polarization-multiplexed, dual-beam swept source optical coherence tomography angiography. Invest. Ophthalmol. Vis. Sci. 2017;58(8):3811.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : Optical coherence tomography angiography (OCTA) is a novel imaging modality that could be used to evaluate capillary dropout and neovascularization in diabetic retinopathy. In this application, a critical limitation is the narrow field of view of current commercial OCTA systems, which usually have an A-line speed of 70~100 kHz. Although faster swept sources (up to 2 MHz) are available commercially, the signal to noise ratio is limited because the beam power is limited by laser safety. A dual-beam OCT could allow the use of greater power to satisfy both speed, signal, and safety requirements.

Methods : A 100-kHz swept-source laser is employed. In the sample arm, the light is split into two orthogonal-polarized beams with a separation angle of 20 degrees by a Wollaston prism. The two beams are separated by 14 degrees on the corneal plane, corresponding to a separation of 4.2 mm on the retina (Fig. 1). The OCT images from the two beams are depth encoded. A 5-mm glass plate is used to set a constant path delay difference between the two beams. The split-spectrum amplitude &phase gradient angiography algorithm was used to compute flow signal.

Results : The measured sensitivities for the orthogonal-polarized beams are 95 and 94 dB, respectively. With a scanning angle of 17 degrees, OCTA with a field of view of 5×5 mm2 (400×400 pixels) for each beam was captured in four seconds. By montaging the two 5×5 mm2 OCTAs from the two beams, a wide-field retinal OCTA with a field of view of about 5×8 mm2 (400×640 pixels) was obtained (Fig. 2).

Conclusions : Polarization multiplexing of OCT beams is an effective approach to improve the system speed without sacrificing the system sensitivity. With a dual-beam setup, capillary-resolution wide-field OCTA is possible using a 100 kHz swept laser.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

 

Fig. 1. (A) Photography of the dual beam manipulation components in the OCTA system. (B) Schematic of the dual-beam OCTA system.

Fig. 1. (A) Photography of the dual beam manipulation components in the OCTA system. (B) Schematic of the dual-beam OCTA system.

 

Fig. 2. (A) Overlaid structure (gray) and angiographic (red) cross-sectional OCT images from the 2 beams. (B) En face retinal OCT angiogram around the fovea by montaging the angiogram from the two beams.

Fig. 2. (A) Overlaid structure (gray) and angiographic (red) cross-sectional OCT images from the 2 beams. (B) En face retinal OCT angiogram around the fovea by montaging the angiogram from the two beams.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×