SS-OCT enables increased speed, deeper penetration, but steeper cost
SAN ANTONIO – Swept source OCT has many benefits over spectral domain OCT, but its biggest obstacle today is cost, according to Jay S. Duker at the American Academy of Optometry annual meeting.
SS-OCT is a form of fourier domain detection, which is how the echo time delay is calculated in the device, he said.
The SS light source is a tunable laser that rapidly changes the wavelength, which is very expensive, he added. The reflections of depth are detected with photodetectors, not with a camera as with SD-OCT. The longer wavelength of SS-OCT images (1,000 nm to 1,300 nm) can penetrate cataracts better.
The first SS-OCT was commercially available from Topcon about 5 years ago, he said.
“There are several clinical advantages with SS-OCT: You get a much better scanning range and you do it without a loss of sensitivity because of the speed of the machine,” Duker said. “There’s also no sensitivity roll-off, like with SD-OCT.”
The benefits of SS-OCT include: higher speed, lower noise, longer image range and deeper image penetration.
A big disadvantage is the price; it is much more expensive than SD-OCT, he said. There is also less axial resolution in SS-OCT, at 4 to 5 microns, compared to the 6 to 8 microns of SD-OCT.
There are currently two commercially available units: Zeiss Plex Elite 9000 and the Topcon Triton DRI. – by Abigail Sutton
Duker JS. SS-OCT: What is it, what it does. Presented at: American Academy of Optometry annual meeting; San Antonio; November 7-10, 2018.
Disclosure: Duker is a consultant for and receives funding from Optovue, Topcon and Zeiss.