Abstract
Purpose :
To demonstrate high-definition wide-field angiographic imaging of the human retina.
Methods :
: A 200 kHz swept-source OCT system was developed using a tunable laser (Axsun, Inc.) operating at 1044 nm central wavelength. The laser has a tuning range of 104 nm, which provided an axial resolution of 5.7 microns full-width-half-maximum in tissue. The sample arm included a slit-lamp base, a chin rest, an iris camera, a pico-projector fixation target, and an electrically tunable lens for rapid focusing. The k-clock frequency was electronically doubled to increase the axial imaging range from 3.5 mm to 7.0 mm. A split-spectrum algorithm that combines both phase and amplitude information was used for angiographic calculation.
Results :
Using only 2 B-frames at each location, high-definition (10~15 micron sampling interval) OCT angiography could be captured over 8x8mm or 10x6mm areas in 4 seconds. By montaging four 10x6mm scans, an ultrawide-field OCT angiography with 10x21 mm (35x70°) field of view was demonstrated (Fig. 1). The scan location was controlled by moving the fixation target using the pico-projector. The total imaging time for ultrawide field of view can be accomplished in 15 minutes.
Conclusions :
By using a highly efficient angiography algorithm and a fast OCT system, wide-field OCT angiography could be achieved without sacrificing sampling density or extending acquisition time. Ultrawide field of view can be realized by montaging a few wide-field scans.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.