Normalized Blood Flow Index in Optical Coherence Tomography Angiography Provides a Sensitive Biomarker of Early Diabetic Retinopathy

Abstract

Purpose To evaluate the sensitivity of normalized blood flow index (NBFI) for detecting early diabetic retinopathy (DR). Methods Optical coherence tomography angiography (OCTA) images of healthy controls, diabetic patients without DR (NoDR), and patients with mild nonproliferative DR (NPDR) were analyzed in this study. The OCTA images were centered on the fovea and covered a 6 mm × 6 mm area. Enface projections of the superficial vascular plexus (SVP) and the deep capillary plexus (DCP) were obtained for the quantitative OCTA feature analysis. Three quantitative OCTA features were examined: blood vessel density (BVD), blood flow flux (BFF), and NBFI. Each feature was calculated from both the SVP and DCP and their sensitivities to distinguish the three cohorts of the study were evaluated. Results The only quantitative feature capable of distinguishing all three cohorts was NBFI in the DCP image. Comparative study revealed that both BVD and BFF were able to distinguish the controls and NoDR from mild NPDR. However, neither BVD nor BFF was sensitive enough to separate NoDR from the healthy controls. Conclusions The NBFI has been demonstrated as a sensitive biomarker of early DR, revealing retinal blood flow abnormality better than traditional BVD and BFF. The NBFI in the DCP was verified as the most sensitive biomarker, supporting that diabetes affects the DCP earlier than SVP in DR. Translational Relevance NBFI provides a robust biomarker for quantitative analysis of DR-caused blood flow abnormalities, promising early detection and objective classification of DR.

Deep learning-based optical coherence tomography angiography image construction using spatial vascular connectivity network

“…OCTA is label-free and thus is completely non-invasive, compared to traditional fluorescein angiography. Studies have shown that OCTA provides improved capability for detecting subtle vascular distortions associated with the progression of retinal pathology, such as vessel dropout, foveal abnormalities, and increased vessel tortuosity 1 , 2 . Studies demonstrate that OCTA could even detect microaneurysms that were undetected on dilated clinical examination 3 .…”

Differential Artery–Vein Analysis Improves OCTA Classification of Diabetic Retinopathy

“…Extensive research has focused on quantitative analysis of OCTA images for the objective detection and classification of retinal diseases [12][13][14][15][16][17][18][19][20][21][22][23]. Previous work by Alam et al [24] and Son et al [25] leveraged en face OCT and en face OCTA features for AV segmentation through quantitative feature analysis.…”

Differential Artery–Vein Analysis Improves OCTA Classification of Diabetic Retinopathy

“…Extensive research has focused on quantitative analysis of OCTA images for the objective detection and classification of retinal diseases [12][13][14][15][16][17][18][19][20][21][22][23]. Previous work by Alam et al [24] and Son et al [25] leveraged en face OCT and en face OCTA features for AV segmentation through quantitative feature analysis.…”