Abstract
PURPOSE: To determine whether baseline retinal and choriocapillaris (CC) vascular features measured by OCT angiography (OCTA) can predict diabetic retinopathy (DR) progression or visual acuity (VA) decline in a multiethnic longitudinal cohort. DESIGN: Prospective longitudinal cohort study. SUBJECTS: A total of 309 eyes from 192 patients with type 2 diabetes mellitus were recruited from a tertiary eye center in Singapore. METHODS: All participants underwent 3 × 3 mm swept-source OCTA imaging at baseline. Quantitative vascular parameters-including vessel density (VD), perfusion density (PD), and CC flow deficit percentage-were obtained from the superficial and deep retinal layers and from the CC. Larger retinal arterioles and venules were analyzed separately from capillary networks. Diabetic retinopathy progression was defined as a ≥2-step increase on the ETDRS severity scale over 2 years, while VA decline was defined as >1-line reduction in best-corrected VA. Logistic regression and area under the receiver operating characteristic curve (AUC) analyses were used to evaluate predictive performance. MAIN OUTCOME MEASURES: Progression of DR and VA decline over 2 years, as predicted by baseline OCTA metrics. RESULTS: Over 2 years, 49 eyes (15.9%) demonstrated DR progression. Significant predictors in the superficial layer included larger foveal avascular zone (FAZ) area (odds ratio [OR] = 6.612; P = 0.034), longer perimeter (OR = 1.583; P = 0.002), poorer circularity (OR = 3.23; P = 0.019), higher large-vessel PD (OR = 1.561; P < 0.001) and VD (OR = 2.878; P < 0.001), and lower whole-vessel VD (OR = 0.798; P = 0.010). Adding FAZ perimeter and large-vessel VD improved prediction accuracy (AUC increased from 0.709-0.822). For VA loss, higher superficial large-vessel PD (OR = 1.609; P = 0.002) and lower capillary PD (OR 0.8; P = 0.010) were significant predictors, improving AUC from 0.602 to 0.702. CONCLUSIONS: Enlargement and irregularity of the FAZ, along with increased superficial large VD, independently predict DR progression. Incorporating FAZ and large-vessel OCTA parameters enhances prediction models for both DR worsening and vision decline in patients with diabetes. FINANCIAL DISCLOSURES: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.