Abstract
Presentation Description :
Recent advances in OCT technology have dramaticaly increased in imaging speed. Swept source OCT (SS-OCT) can achieve speeds ~10x faster than current commercial spectral domain OCT (SD-OCT). In addition SS-OCT enables imaging at longer 1050nm wavelengths compared with SD-OCT at 840nm. Long wavelengths have increased immunity to ocular opacities as well as improved image penetration, enabling imaging of choroidal structure. Ultrahigh speeds achieved by state of the art OCT are important not only for retinal coverage, but also for functional OCT. OCT angiography (OCTA) is a recent functional extension of OCT which enables three dimensional visualization of retinal and choroidal microvasculature. OCTA detects motion contrast by performing repeated B-scans in the same retinal location and measuring decorrelation signals which are generated by moving erythrocytes. OCTA has the advantage that it does not require injection of dyes and therefore can be performed on every patient visit. However, since OCTA requires repeated scanning, extremely high acquisition speeds are required to achieve retinal coverage. OCTA using SS-OCT is especially promising because it enables imaging of the choriocapillaris, detecting flow impairment and atrophy. Ultrahigh speeds also enable functional OCT methods for measuring total retinal blood flow. En face Doppler OCT measures blood flow in an en face plane by volumetrically imaging the central retinal vasculature. En face Doppler has the important advantage that measurement of Doppler angle is not required and flow can be measured using automated algorithms. Ultrahigh speeds are required because flow measurements involve the acquisition of an entire OCT volume rather than individual B-scan images as in standard Doppler OCT. In addition, rapidly repeated volumes are required to average cardiac pulsatility. These examples of functional OCT can be facilitated by the next generation of ultrahigh speed OCT technology. These new methods promise to provide powerful tools for clinical assessment as well as for fundamental research in pathogenesis.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.