To examine the associations of peripapillary microvascular metrics with diabetic retinopathy (DR) incidence and development using swept-source optical coherence tomography angiography (SS-OCTA).

Prospective cohort study.

A total of 1033 eyes from 1033 patients with type 2 diabetes mellitus (T2DM) were included, with 2-year follow-up. The peripapillary microvascular metrics at the superficial capillary plexus (SCP) were measured by SS-OCTA at the baseline, including peripapillary vascular density (pVD) and peripapillary vascular length density (pVLD). The DR incidence and progression were evaluated with 7 standard fields of stereoscopic color fundus photographs. The associations were tested with logistic regression models after adjusting for established risk factors and confounding factors. The prediction value of OCTA metrics was examined with the elevation of area under the receiver operating characteristic curve (AUROC).

The 2-year incidence of diabetic retinopathy (DR) was 25.1% (n = 222) in non-DR (NDR) eyes, 7.4% DR progression (n = 11) in DR eyes, and 4.17% RDR eyes (n = 43) in all eyes. After adjusting for established factors, lower whole-image pVD (wi-pVD) (relative risk [RR] = 0.81; 95% CI = 0.68-0.96; P = .015), circular pVD (circ-pVD) (RR = 0.79; 95% CI = 0.66-0.95; P = .013), whole-image pVLD (wi-pVLD) (RR = 0.79; 95% CI = 0.67-0.94; P = .008), and circular pVLD (circ-pVLD) (RR = 0.76; 95% CI = 0.63-0.91; P = .003) were significantly associated with increased risk of DR incidence; wi-pVD (RR = 0.48; 95% CI = 0.35-0.67; P < .001), circ-pVD (RR = 0.65; 95% CI = 0.45-0.94; P = .023), and wi-pVLD (RR = 0.46; 95% CI = 0.33-0.66; P < .001) were associated with incident risk of RDR. Both pVD and pVLD of SCP were not significantly associated with DR progression. The AUROC for the DR incidence risk prediction model increased from 0.631 to 0.658 (4.28%; P = .041) by circ-pVLD; the AUC of the RDR incidence risk prediction model increased from 0.631 to 0.752 by wi-pVD (19.18%; P = .009), to 0.752 by circ-pVD (19.18%; P=.009), and to 0.752 by wi-pVLD (19.18%; P = .009).

Lower pVD and pVLD of SCP are associated with 2-year incident DR and RDR among the T2DM population. The peripapillary metrics imaged by SS-OCTA can provide additional value to the prediction of DR incidence and development.