Quantitative analysis of macular vessel density in noproliferative diabetic retinopathy by OCTA

AIM: To analyse the characteristic of macular microcirculation detected by optical coherence tomography angiography(OCTA)in nonproliferative diabetic retinopathy(NPDR). METHODS: Vessel density of 3mm×3mm centered on the fovea(3mm×3mm VD), parafoveal vessel density(parafoveal VD)and foveal vessel density(foveal VD)were measured by OCTA in healthy people, NDR, mild NPDR, moderate NPDR, and severe NPDR groups. RESULTS: Deep 3mm×3mm VD, deep parafoveal VD and deep foveal VD were decreased gradually in groups. There was statistically significant difference between moderate NPDR, severe NPDR and others in deep 3mm×3mm VD and parafoveal VD(P<0.01). There was statistically significant difference between severe NPDR and control group in deep foveal VD(P=0.006). Superficial 3mm×3mm VD and superficial parafoveal VD are statistically significant in groups. There was statistically significant difference between moderate NPDR group and control group in superficial 3mm×3mm VD and parafoveal VD(P<0.01). There was statistically significant difference between severe NPDR group and others except moderate NPDR group in superficial 3mm×3mm VD, parafoveal VD(P<0.01). There was a significant correlation of deep and superficial 3mm×3mm VD,deep and superficial parafoveal VD, deep parafoveal VD with VA. CONCLUSION: Deep vessel density decreased more significantly in moderate NPDR and severe NPDR groups and deep parafoveal vessel density might be a potential biomarker of DR.