光相干断层扫描血管成像鉴别缺血型与非缺血型视网膜分支静脉阻塞

The role of optical coherence tomography angiography to distinguish ischemic and non-ischemic branch retinal vein occlusion

目的观察光相干断层扫描血管成像(OCTA)对缺血型与非缺血型视网膜分支静脉阻塞(BRVO)的鉴别价值。方法前瞻性临床观察性研究。2020年1月至2021年1月于天津医科大学眼科医院检查确诊的BRVO患者44例44只眼纳入研究。其中,男性24例24只眼,女性20例20只眼。所有患眼均经连续3次抗血管内皮生长因子(VEGF)药物治疗后黄斑水肿消退。所有患眼均行最佳矫正视力(BCVA)、眼压、超广角荧光素眼底血管造影(UWFFA)及OCTA检查。根据UWFFA检查结果将患眼分为缺血组、非缺血组,均为22例22只眼。采用OCTA仪对患眼黄斑区3 mm×3 mm范围进行扫描,测量视网膜浅层毛细血管层(SCP)、深层毛细血管层(DCP)的血流密度(SVD、DVD)、中心凹血流密度(SFVD、DFVD)、旁中心凹血流密度(SPFVD、DPFVD)、受累半侧血流密度(SHVD、DHVD)、受累象限血流密度(SQVD、DQVD),中心凹视网膜厚度(CRT),中心凹无血管区(FAZ)面积、周长(PERIM)、非圆度指数(AI)以及FAZ范围300μm宽度内的血流密度(FD-300)。缺血组和非缺血组间各参数比较采用两独立样本t检验。应用受试者工作特征(ROC)曲线分析测量血流密度预测缺血型BRVO的曲线下面积(AUC),确定预测缺血型BRVO的临界值及对应的灵敏度和特异性,以AUC>0.9为预测效能良好。结果缺血组、非缺血组患眼BCVA(t=1.544)、眼压(t=-0.404)、SFVD(t=0.444)、DFVD(t=-0.812)、CRT(t=1.082)、FAZ面积(t=-0.785)、PERIM(t=-0.685)、AI(t=1.047)比较,差异无统计学意义(P>0.05);年龄(t=2.194)、SVD(t=-3.796)、SPFVD(t=-4.181)、SHVD(t=-4.700)、SQVD(t=-3.594)、DVD(t=-2.324)、DPFVD(t=-2.476)、DHVD(t=-2.118)、DQVD(t=-6.529)、FD-300(t=-5.116)比较,差异有统计学意义(P<0.05)。ROC曲线分析结果显示,DQVD预测缺血型BRVO的AUC最大(0.917),其最佳临界值为33.75%,灵敏度和特异性分别为90.9%和81.8%。结论OCTA可定量评估BRVO患眼黄斑区SCP、DCP的微血管结构,有助于鉴别缺血型和非缺血型BRVO。

Objective To observe the value of optical coherence tomography(OCTA)in distinguishing ischemic and non-ischemic branch retinal vein occlusion(BRVO).Methods A prospective clinical observational study.From January 2020 to January 2021,44 eyes of 44 patients with BRVO diagnosed in Tianjin Medical University Eye Hospital were included in the study.Among them,there were 24 eyes of 24 males and 20 eyes of 20 females.The macular edema subsided after three consecutive anti-vascular endothelial growth factor(VEGF)drug treatments.All the affected eyes underwent best corrected visual acuity(BCVA),intraocular pressure,ultra-wide-angle fluorescein fundus angiography(UWFFA),and OCTA examination.According to the results of UWFFA,the affected eyes were divided into ischemic group and non-ischemic group,with 22 eyes in 22 patients.The macular area of the affected eye with an OCTA instrument were scaned in the range of 3 mm×3 mm to measure the blood flow density(SVD,DVD),foveal blood flow density(SFVD,DFVD),parafoveal blood flow density(SPFVD,DPFVD),affected hemilateral blood flow density(SHVD,DHVD)and affected quadrant blood flow density(SQVD,DQVD)of the superficial capillary layer(SCP)and deep capillary layer(DCP)of the retina,foveal retinal thickness(CRT),fovea avascular zone(FAZ)area,perimeter of FAZ(PERIM),out-of-roundness index(AI),and blood flow density within 300μm width of FAZ(FD-300).The two-sample independent t test was used to compare the parameters between the ischemic group and the non-ischemic group.Receiver operating characteristic(ROC)curve analysis was used to measure the area under the curve(AUC)of blood flow density to predict ischemic BRVO,determine the critical value for predicting ischemic BRVO and the corresponding sensitivity and specificity,with AUC>0.9 as the prediction performance was good.Results The differences of BCVA(t=1.544),intraocular pressure(t=-0.404),SFVD(t=0.444),DFVD(t=-0.812),CRT(t=1.082),FAZ area(t=-0.785),PERIM(t=-0.685),AI(t=1.047)of the eyes in the ischemic group and non-ischemic group were not statistically significant(P>0.05).The differences of age(t=2.194),SVD(t=-3.796),SPFVD(t=-4.181),SHVD(t=-4.700),SQVD(t=-3.594),DVD(t=-2.324),DPFVD(t=-2.476),DHVD(t=-2.118),DQVD(t=-6.529)and FD-300(t=-5.116)of the eyes in the ischemic group and non-ischemic group area were statistically significant(P<0.05).ROC curve analysis results showed that DQVD predicted the AUC of ischemic BRVO the largest(0.917),the best cut-off value was 33.75%,and the sensitivity and specificity were 90.9%and 81.8%,respectively.Conclusion OCTA can quantitatively assess the microvascular structure of SCP and DCP in the macular area of BRVO eyes,and contribute to distinguish ischemic and non-ischemic BRVO.