New optical coherence tomography (OCT) devices are in development with the goal of expanding the utility of OCT in the clinic
by providing better resolution, faster speed, and software to help clinicians better understand the nuances of diseases and
how they respond to therapy. Dr Jay S. Duker looked at the past, present and future of the technology during the Retina Subspeciality
Day at the annual meeting of the American Academy of Ophthalmology.
"The OCT story is one of engineering success triumphing over darkness," said Dr Duker, director, New England Eye Center, and
professor and chairman of ophthalmology, Tufts University School of Medicine, Tufts University School of Medicine, Boston,
The first OCTs that became commercially available in 1996 were time-domain (TD) instruments. Those reached their pinnacle
in 2002 when the Stratus OCT was introduced by Zeiss. That instrument, which had 10 μm axial resolution and obtained 400 axial
scans per second, remained the state-of-the-art technology until recently.
"TD-OCT was very useful, but it was not perfect," according to Dr Duker, who explained that the device had registration errors,
skip areas, software breakdowns and, often, inadequate resolution.
Over the past decade, many new OCT instruments have become available that are all based on Fourier-domain detection. Spectral-domain
(SD) OCT became commercially available in 2006 and swept-source OCT is being used in research but is not yet commercially
available. SD-OCT is faster than TD-OCT and can obtain from 20000 to 52000 scans per second. It also has a broader band width
that increases the axial resolution from 4 to 7 μm.