光学相干断层扫描血管成像技术在糖尿病视网膜病变中的应用

Application of optical coherence tomography angiography for diabetic retinopathy

目的应用光学相干断层扫描血管成像技术(OCTA)监测糖尿病视网膜病变(DR)患者黄斑中心凹无血管区(FAZ)面积及视网膜微血管密度(MVD),分析两者在DR临床分期中的意义。方法选取232例260眼糖尿病患者,依据DR的国际分期标准,分为非增生期糖尿病视网膜病变(NPDR)的轻度NPDR组(63眼)、中度NPDR组(64眼)、重度NPDR组(66眼)及增生期糖尿病视网膜病变(PDR)Ⅳ期组(67眼),同时选择健康者作为正常对照组(60眼)。应用OCTA获得各组黄斑血流密度图、测量黄斑FAZ、MVD;同时检测各组糖化血红蛋白(HbAlc)、空腹血糖(FPG)。统计分析浅层视网膜及深层视网膜毛细血管层的FAZ、MVD的变化与糖尿病视网膜病变进展的相关性,以及HbAlc、FPG与MVD的相关性。结果随着糖尿病视网膜病变的进展,OCTA检查各组患者显示FAZ面积随着病情加重而逐渐增大,MVD逐渐降低,出现无灌注区;HbAlc、FPG亦逐渐加重。统计分析显示正常对照组与糖尿病各组以及糖尿病各组间结果均有差异,且差异有统计学意义(P<0.05)。采用spearman秩相关性分析显示表层视网膜、深层视网膜毛细血管层的FAZ、MVD的变化与糖尿病病情的进展具有正相关性,HbAlc、FPG与MVD亦具有正相关性。结论 OCTA检查能显示糖尿病患者黄斑区视网膜的微循环障碍变化,可以作为DR分期的一个临床指标。

Objective To analyze the difference in clinical stages for patients with diabetic retinopathy(DR) through monitoring the area of foveal avascular zone(FAZ) and retinal microvessel density(MVD) by using optical coherence tomography angiography(OCTA). Methods 232 patients(260 eyes) with DR were divided into four groups according to the international staging criteria. Specifically,the patients were respectively categorized as mild non-proliferative diabetic retinopathy(NPDR) group(63 eyes),moderate NPDR group(64 eyes),Severe NPDR group(66 eyes) and hyperplastic diabetic retinopathy(PDR) stage Ⅳ group(67 eyes). The healthy subjects(60 eyes) were selected as the control group. The macular FAZ and MVD were measured using OCTA. At the same time,the glycated hemoglobin(HbAlc) and fasting plasma glucose(FPG) of the subjects were tested. The changes of FAZ and MVD in the surface and deep retinal capillary layers,and the changes of HbAlc,FPG were statistically analyzed and compared between the different groups. The correlation between the changes in FAZ,MVD and the progression of DR,the correlation between changes in HbAlc,FPG and MVD were established respectively.Results OCTA examination showed that FAZ gradually increased,while MVD gradually decreased in patients with DR,and that no perfusion area appeared in these patients. The levels of Hb Alc and FPG also gradually increased in each group with the development of DR. Statistical analysis showed that the differences between the control group and diabetes groups were significant(P<0.05). The same difference was found between the diabetes groups. Correlation coefficient showed that the expression of FAZ and MVD in the surface and deep retinal capillary layers were positively correlated with the progression of diabetes(P<0.05). The same positive correlation was found between HbAlc,FPG and MVD. Conclusion OCTA examination may show the changes in the microcirculation disturbance of the macular retina in diabetic patients,which can be used as a clinical indicator of DR staging.