Abstract
Purpose :
To compare the difference in diabetic microaneurysm (MA) detection between an ultrafast megahertz (MHz) widefield optical coherence tomography angiography (WF-OCTA) device and a commercially available kilohertz (kHz) WF-OCTA device.
Methods :
Patients with advanced diabetic retinopathy (DR) were recruited at the Department of Ophthalmology at the Medical University of Vienna for this cross-sectional study.
Multimodal imaging was performed on the same day, including imaging with a custom-built swept-source MHz WF-OCTA prototype (A-scan rate: 1.7 MHz; FOV: 18 mm in diameter) equipped with deep learning (DL) based 3D denoising, kHz WF-OCTA (A-scan rate: 200 kHz; FOV: 12x12 mm; PLEX® Elite 9000, ZEISS, Dublin, CA), fluorescein angiography (FA) and color fundus (CF) imaging (Optos®, Optos California). Microaneurysms (MAs) were manually evaluated on en face images by a human expert reader within an extended ETDRS grid consisting of a central 1 mm diameter disc, inner (IR, 0.5–1.5 mm), outer (OR, 1.5–3.0 mm) and extended ring (ER, 3.0 mm-6.0 mm).
Results :
Thirty-four eyes of 34 patients with severe non-proliferative DR (n=11) and proliferative DR (n=23) were included in this study. A mean number of 160 ± 145 (± standard deviation) MAs per eye were detected from the gold standard FA images. MHz WF-OCTA and kHz WF-OCTA detected 55% and 44% of MAs, respectively. Significantly more MAs in total were detected on MHz WF-OCTA compared to kHz WF-OCTA (p=0.007). MHz WF-OCTA outperformed kHz WF-OCTA in MA detection in the outer (p=0.006) and the extended ETDRS ring (p=0.031). CF showed the lowest detection rate with 34% of MAs. Details of MA numbers in specific ETDRS rings are shown in Table 1.
Conclusions :
MHz WF-OCTA in combination with DL-based image denoising techniques outperformed kHz WF-OCTA in the detection of diabetic MAs, which was pronounced in the extra-macular and peripheral regions of an extended ETDRS grid.
This abstract was presented at the 2023 ARVO Imaging in the Eye Conference, held in New Orleans, LA, April 21-22, 2023.