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Chen et al. (910) wrote an exciting article on the development of high-speed ultrahigh resolution optical coherence tomography (hsUHR-OCT), also called spectral domain OCT or Fourier domain OCT. In 'Spectral Domain Optical Coherence Tomography: Ultra-high Speed, Ultra-high Resolution Ophthalmic Imaging', the authors describe two devices created by the group, one capable of scanning at 29,000 A-scans/second with 6 micron axial resolution, and the other scanning at nearly 15,000 A-scans/second with 3.5 micron axial resolution.
Fourier domain OCT was introduced by Fercher et al. in 1995.1 The technique permits high speed scanning, since it has extremely high sensitivity and all of the information from a given A-scan is acquired simultaneously. Several laboratories have created spectral or Fourier domain OCT devices, some with high or ultrahigh resolution. In this article, the group describes and demonstrates scans of a normal eye of a single healthy 39 year-old individual. The scans are of high quality and show the ability to discriminate retinal layers with considerably more definition that with the currently available Stratus OCT (Carl Zeiss Meditec, Inc., Dublin, CA). They also show that while 6 micron axial resolution improves on Stratus OCT, still more layers of the retina can be seen with 3.5 micron hsUHR-OCT. Further, they demonstrate in vivo Doppler hsUHR-OCT, illustrating retinal blood flow.