Abstract
Purpose :
Posterior eye imaging with optical coherence tomography (OCT) and OCT angiography (OCTA) suffers from involuntary eye movements. We have developed a motion-free Lissajous scan OCT method, which enabled accurate assessment of morphology and metrics of diseases. In this paper, further accurate motion correction is enabled by simultaneously using en face OCT and OCTA images for motion estimation. The performance is compared to the previous Lissajous method which uses only OCTA for motion estimation.
Methods :
A custom-made 1.0-µm swept-source OCT device with a scan speed of 100,000 A-line/s is used. The OCT probe beam scans along a modified Lissajous pattern, which is designed for both OCT and OCTA. The eye motion is estimated by co-registering small overlapped portions of an en face Lissajous scan. Motion-free three-dimensional volumes and en face maps of OCT images were created by using the estimated motion amounts. The lateral motion estimation was performed by two means; (1) using only en face OCTA and (2) using en face OCT and OCTA. In order to compare the image qualities obtained by the two means, the motion-corrected superficial retinal OCTA images were manually scored from 0 (low) to 5 (high) by an expert.
For this comparison, 73 eyes of 64 patients with retinal abnormalities were scanned over 3×3 mm2 area.
Results :
Figure 1 shows motion-corrected en face OCT and OCTA images of a representative case. The mean scores of the motion-corrected superficial OCTA images are 2.9 for OCTA-only motion estimation and 3.0 for OCT-and-OCTA correction. The score of OCT-and-OCTA correction is statistically significantly better than the OCTA-only correction (p-value=0.02, Wilcoxon's signed-rank test).
Conclusions :
The motion-free Lissajous OCT with a newly developed OCT-and-OCTA based motion estimation gave better image quality than that with OCTA-only motion estimation.
This is a 2021 ARVO Annual Meeting abstract.