Regional assessment of choroidal vascularity index in patients with pre- and early-stage diabetic retinopathy using ultra-wide-field OCTA.

Purpose: To characterize the regional variations of choroidal vascularity index (CVI) in patients with diabetes mellitus (DM) using ultra-wide-field optical coherence tomography angiography (UWF-OCTA) and identify their correlations with the onset of diabetic retinopathy (DR). Methods: This cross-sectional, monocular-sampling study recruited 141 participants from four age-matched groups: no DM (NDM), no DR with early DM (EDM) and late DM (LDM), and mild-moderate non-proliferative diabetic retinopathy (mNPDR). UWF-OCTA was employed for circular scans centered on the fovea. CVI in the central region (0-1 mm) and four quadrants of the concentric rings with different ranges (1-3, 3-6, 6-9, 9-12, 12-15, 15-18 mm) was obtained for analysis together with their demographic and clinical data. The Area under the receiver operating characteristic curve (AUC) was calculated to assess the diagnostic efficacy for mNPDR and compared using the DeLong test. Results: The average CVI was lower in patients with mNPDR compared to other groups across all regions. Although there was no significant difference in DM duration between the LDM and mNPDR groups, a notable variance in CVI was observed, particularly ( Conclusion: Reduced CVI was observed in the most peripheral region, highly predictive for mNPDR and associated with the declining renal function, thus enhancing the potential of UWF-OCTA to integrate into DM management and promote early DR screening.