AIM: To quantitatively analyze the microcircular and structural changes of the macular and peripapillary area in patients with diabetic kidney disease(DKD), exploring non-invasive effective monitoring indexes that can predict the occurrence and development of diabetic kidney disease used optical coherence tomography angiography(OCTA).

METHODS: A cross-sectional study. The diabetic patients(52 cases)and healthy subjects(20 cases)who came to Shanxi Provincial People's Hospital from January 2020 to January 2021 were collected, and the diabetes mellitus(DM)patients were further divided into DKD group(23 cases)(complicated with diabetic kidney disease)and non-DKD group(29 cases)(not complicated with diabetic kidney disease). All patients underwent slit-lamp microscopy, best corrected visual acuity(BCVA), OCTA and fundus color photography. OCTA was used to scan the macula and peripapillary area of all participants, measuring the shallow and deep blood flow density, the area and circumference of the fovea(FAZ), vascular density in the 300μm area around FAZ(FD300), retinal thickness, peripapillary-VD, retinal nerve fiber layer(RNFL)thickness, and ganglion cell complex(GCC)thickness. The correlation between the changes of these parameters in OCTA, DR staging and DKD staging was analyzed.

RESULTS: Parafoveal SCP-VD, perifoveal DCP-VD, peripapillary-VD, and FD300 showed a decreasing trend among the healthy group, non-DKD group, and DKD group(P<0.05). The foveal DCP-VD was decreased only in the DKD group(P<0.05), and there was no significant difference in the SCP-VD of fovea among the three groups(P>0.05). FAZ area and GCC thickness were gradually increased among healthy group, non-DKD group and DKD group(P<0.05). DR staging was positively correlated with DKD staging(r_s=0.648, P<0.05). Parafoveal SCP-VD, parafoveal DCP-VD, and perifoveal DCP-VD were negatively correlated with DKD staging(r_s= -0.535, P=0.009; r_s= -0.712, P<0.001; r_s= -0.641, P=0.001). Compared with non-DKD group, DKD group had higher SBP, lower eGFR, and higher UACR(P<0.05).

CONCLUSION: OCTA can detect retinal microcirculation and structural changes in patients with DKD, including decreased vessel density in the macular and peripapillary area, increased FAZ area and GCC thickness. More importantly, we found that retinal vessel density decreased with renal function impairment, suggesting that retinal vessel density may be a noninvasive and effective predictor in the severity of DKD.