140° ultrawide-field handheld swept-source OCT angiography

Ultrawide-field optical coherence tomography angiography (UWF-OCTA) is critical for detecting peripheral retinal vascular abnormalities in conditions like retinopathy of prematurity (ROP) and diabetic retinopathy (DR). An optimized scanning pattern can balance UWF-OCTA sensitivity to capillaries with slow flow and resistance to motion artifacts and noise. To generate high-quality 140° OCTA on a system without eye-tracking, we adopted a novel bidirectional interleave scanning pattern, which can eliminate flyback time. We also investigated two B-scan intervals (8 ms and 4 ms), in order to determine the most reasonable option for ROP imaging. Our preliminary results indicate that the UWF-OCTA with 4 ms interval can provide better performance in resolving choroidal vasculature and delivering overall clean angiograms with the least motion effects.