目的：分析光学相干断层扫描血管成像(OCTA)评估黄斑中心凹无血管区(FAZ)参数对早期糖尿病视网膜病变(DR)的诊断价值。

方法：回顾性研究。选择2019-06/2022-12我院收治的2型糖尿病(T2DM)合并糖尿病视网膜病变(DR)患者209例209眼为DR组，根据分期分为DR轻度组患者115例115眼、DR中度组患者54例54眼、DR重度组患者40例40眼，单纯T2DM未合并DR患者100例100眼为No-DR组，选择同期体检健康人群70例70眼为对照组。所有受检者均行OCTA检查，DR组根据病变程度入组(若双眼病变程度一致，则随机取一眼进行研究)，对照组和No-DR组随机一眼纳入研究。比较各组受检者黄斑中心凹无血管区周长(PERIM)、FAZ横径、FAZ竖径、FAZ面积、黄斑中心凹视网膜厚度(MFRT)、非圆度指数(AI)、FAZ周围300 μm范围内全层视网膜血流密度(FD-300)、FAZ血管线性密度(VD)变化情况，采用Pearson相关性分析一般资料与FAZ相关指标的相关性，采用受试者工作特征(ROC)曲线评估黄斑FAZ指标诊断DR的价值。

结果：DR轻度组、DR中度组、DR重度组患者FBG、MFRT、FAZ面积、PERIM水平均明显高于No-DR组和对照组，AI、VD水平明显低于No-DR组(均P<0.05)； No-DR组、DR轻度组、DR中度组、DR重度组患者Cys-C、FAZ横径、FAZ竖径明显高于对照组，FD-300血流密度明显低于对照组(均P<0.05)； MFRT与年龄呈正相关(r=0.295，P=0.001)； AI、VD与年龄呈负相关(r=-0.296、-0.235，均P<0.05)； MFRT、FAZ面积、PERIM、AI、VD诊断DR的曲线下面积(AUC)分别为0.745、0.738、0.696、0.792、0.847。

结论：DM患者可出现FAZ结构及微循环改变，FAZ相关参数在诊断早期DR方面具有一定价值。

METHODS: Retrospective study. A total of 209 cases(209 eyes)of type 2 diabetes mellitus(T2DM)with DR admitted to our hospital from June 2019 to December 2022 were selected as DR group. The DR group was divided into three groups, with 115 cases(115 eyes)in mild group, 54 cases(54 eyes)in moderate group, and 40 cases(40 eyes)in severe group according to stage. Another 100 cases(100 eyes)of T2DM patients without DR were selected as No-DR group, and 70 cases(70 eyes)of healthy people were selected as control group for physical examination at the same time, all of whom underwent OCTA examination. The DR group was enrolled according to the disease degree, one eye was randomly taken for the study if the degree in both eyes was the same, while the control group and the No-DR group were randomly selected for one eye to be included in the study. The perimeter of the foveal avascular area(PERIM), FAZ transverse diameter, FAZ vertical diameter, FAZ area, macular fovea retinal thickness(MFRT), acircularity index(AI), full layer retinal blood flow density within a range of 300 μm around the FAZ(FD-300), and changes in FAZ vascular density(VD)levels among different groups of subjects were compared. Furthermore, Pearson correlation analysis was used to determine the correlation between general data and FAZ related indicators, and receiver operating characteristic(ROC)curve was used to evaluate the diagnostic value of macular FAZ indicators for DR.

RESULTS: The levels of FBG, MFRT, FAZ area, and PERIM in patients with mild, moderate, and severe DR were significantly higher than those in the No-DR group and the control group, while the levels of AI and VD were significantly lower than those in the No-DR group(all P<0.05); patients in the No-DR group, mild DR group, moderate DR group, and severe DR group had significantly higher cystatin C, FAZ transverse diameter, and FAZ vertical diameter than the control group, while FD-300 vascular density was significantly lower than the control group(all P<0.05); the MFRT was positively correlated with age(r=0.295, P=0.001); The AI and VD was negatively correlated with age(r=-0.296, -0.235, all P<0.05); the area under the curve(AUC)of MFRT, FAZ area, PERIM, AI, and VD for the diagnosis of DR were 0.745, 0.738, 0.696, 0.792, and 0.847, respectively.

CONCLUSION:The structure and microcirculation of FAZ can be changed in DM patients, and the related parameters of FAZ have certain value in the diagnosis of early DR.