Abstract
OBJECTIVE: To evaluate changes in the peripapillary retinal microvasculature and retinal nerve fibre layer (RNFL) in diabetic participants with various stages of diabetic retinopathy (DR) using swept-source optical coherence tomographic angiography (OCTA). DESIGN: Community-based, cross-sectional study. SETTING: This study was conducted in a tertiary teaching hospital in Guangzhou, China. PARTICIPANTS: A total of 1325 ocular-treatment-naive participants, of whom 1115 had no DR and 210 had DR, were recruited in a community in Guangzhou, China. PRIMARY AND SECONDARY OUTCOME MEASURES: A commercially available OCTA device was used to obtain various peripapillary retinal microvascular metrics centred on the optic disc, including vessel density (VD), vessel length density (VLD) and vessel diameter index (VDI). The peripapillary RNFL thickness was automatically obtained using built-in software. Linear regression analyses were used to evaluate the association of the peripapillary OCTA parameters (VD, VLD and VDI), RNFL thickness with various DR stages and average RNFL thickness with peripapillary OCTA parameters. RESULTS: Moderate and severe DR had progressively decreased VD in the peripapillary ring (β = -0.72, 95% CI = -1.31 to -0.14 and -1.79, 95% CI = -2.81 to -0.77, respectively) and other regions (all p<0.05). Similar changes were observed between peripapillary VLD and moderate and severe DR (all p<0.05). Moderate (β = -4.56, 95% CI = -8.97 to -0.15, p=0.043) and severe DR (β = -10.12, 95% CI = -18.29 to -1.95, p=0.015) had significant thinner peripapillary RNFL in the inferior quadrant. VD and VLD were linearly associated with the average RNFL in the peripapillary ring and average peripapillary area (all p<0.05). CONCLUSIONS: The peripapillary retinal microvasculature and RNFL were significantly reduced with the progression of DR, which suggests that monitoring differences in peripapillary microvasculature and the RNFL may be a promising approach to detecting DR progression.