目的：通过光学相干断层扫描血管成像(OCTA)定量分析糖尿病肾病(DKD)患者的黄斑区及视盘周围的微循环和结构改变，探索能够预测DKD发生、发展的无创有效监测指标。

方法：横断面研究。收集2020-01/2021-01期间就诊于山西省人民医院的糖尿病患者52例，包括DKD组23例(合并糖尿病肾病)和非DKD组29例(不合并糖尿病肾病)，另选20例健康人作为健康组。所有患者均行裂隙灯显微镜、最佳矫正视力(BCVA)、OCTA及眼底彩照检查。应用OCTA扫描所有参与者的黄斑及视盘，检测黄斑区浅层血流密度(SCP-VD)和深层血流密度(DCP-VD)、中心凹无血管区(FAZ)面积和周长、FAZ周围300μm区域中心凹血管密度(FD300)、黄斑区视网膜厚度、视盘旁血流密度(peripapillary-VD)、视网膜神经纤维层(RNFL)厚度和神经节细胞复合体(GCC)厚度。并分析OCTA这些参数改变、糖尿病视网膜病变(DR)分期与DKD分期之间的相关性。

结果：旁中心凹、中心凹周围(SCP-VD、DCP-VD)、peripapillary-VD、FD300在健康组、非DKD组、DKD组均呈逐渐减小趋势(P<0.05)，而中心凹DCP-VD仅表现为DKD组的下降(P<0.05)，中心凹SCP-VD在三组之间并无差异(P>0.05)。FAZ面积和GCC厚度在健康组、非DKD组、DKD组均呈逐渐增大趋势(P<0.05)； DR分期与DKD分期呈正相关(r_s=0.648，P<0.05)； 旁中心凹SCP-VD、旁中心凹DCP-VD、中心凹周围DCP-VD与DKD分期呈负相关(r_s=-0.535，P=0.009； r_s=-0.712，P<0.001； r_s=-0.641，P=0.001)； 与非DKD组相比，DKD组患者具有更高的收缩压、较低的估算肾小球滤过率、更高的尿微量白蛋白/尿肌酐(P<0.05)。

结论：通过OCTA可以检测到DKD患者的视网膜微循环及结构改变，表现为黄斑区和视盘周围血流密度降低、FAZ面积增大、GCC增厚。更重要的是，我们发现视网膜血管密度随肾功能损害而降低，这提示视网膜血流密度或许可以作为预测DKD严重程度的一项无创、有效监测指标。

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.

山西省卫生健康委科研课题(No.2020027)