MHz OCT angiography for 60 degree retinal imaging and microscopic choriocapillaris imaging

摘要

The choriocappilaris layer is considered to be one of the first retinal layers affected in age relatedmacular degeneration and other retinal diseases. Imaging this fine vascular layer below theretinal pigment epithelium (RPE) with optical coherence tomography angiography (OCTA) has beenvery challenging due to the high scattering and absorption of the RPE. In OCTA higher inter B-scantimes increase the sensitivity for slow motion and hence improve the contrast of fine vessels.However, it was demonstrated that for the choriocappilaris the opposite is the case. Novel sweptsource laser technology enables acquiring images at A-scan-rates of 1.7 million A-scans per second,which is approx. 17 times faster than the fastest commercially available OCT devices. OCTAimages of the human macula with different inter B-scan times were acquired and compared. Thesame prototype system was also used to acquire single shot wide-field OCTA images with up to 60degree field of view.