Three Dimensional Retinal Structure and Vasculature Imaging by Doppler Analysis With High–Speed Spectral–Domain Optical Coherence Tomography

Abstract

Purpose: : To demonstrate three–dimensional imaging of retinal vasculature by high–speed Spectral Domain OCT. Doppler analysis allowed to extract blood vessels.

Methods: : A high–speed spectral domain OCT system has been developed using a super–luminescent diode with a center wavelength of 840 nm and an optical bandwidth of 50 nm. The axial resolution is 6 µm. This system operates at 18,700 A–scan/sec and acquires one two–dimensional image consisting 1000 A–scans at 18 ms, and a three–dimensional data set consisting of 500 x 250 A–scans within 6.7 seconds. To correct the motion artifact between images, the correlation–based method is applied. Three–dimensional blood flow imaging of retinal vessels is achieved by Doppler analysis for OCT images. The moving regions, i.e. inside of blood vessels are recognized. The motion artifact in flow images due to a motion of a subject is numerically corrected.

Results: : High–speed three–dimensional spectral domain OCT imaging was performed in healthy normal volunteer. Volume datasets allowed visualization of three–dimensional morphology of retina and three–dimensional retinal vasculature are extracted by Doppler analysis. The blood flow of arteries and veins are mapped. SLO like fundus images are acquired from the same volume dataset in projection views and compared to the Doppler analysis results.

Conclusions: : High–speed spectral domain OCT enables the measurements of precise three–dimensional retinal structure and three–dimensional retinal vasculature imaging with Doppler flow analysis.

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retina