目的:测量健康受试者和视网膜静脉阻塞(RVO)患者的非侵入性视网膜静脉血流量(RBF)。
方法:原型名为AO-LDV(自适应光学激光多普勒测速仪),它结合了新的绝对激光多普勒测速仪和自适应光学眼底相机(rtx1,ImagineEyes®,奥赛,法国),研究了作为视网膜血管直径函数的绝对RBF的测量和红细胞速度的同时测量。在健康受试者(n=15)和视网膜静脉阻塞患者(RVO,n=6)。我们还评估了两个测量视网膜血管直径的软件:软件1(自动血管检测,轮廓分析)和软件2(基于使用深度神经网络对血管进行语义分割,使用M2u-Net架构)。
结果:软件2提供了比软件1(64.9%)更高的自动视网膜血管测量率(12,320张AO图像中的99.5%)和更宽的测量值(75.5±15.7μmvs70.9±19.8μm,p<0.001)。对于健康受试者(n=15),测量一只眼睛的所有视网膜静脉以获得总RBF。在健康的受试者中,总RBF为37.8±6.8μl/min。视网膜血管直径与最大速度之间存在显着的线性相关(斜率=0.1016;p<0.001;r2=0.8597),视网膜血管直径与血流量之间存在显着的功率曲线相关性(3.63×10-5×D2.54;p<0.001;r2=0.7287)。总RBF与收缩压和舒张压之间没有发现显着关系,眼灌注压,心率,或者血细胞比容.对于RVO患者(n=6),与对侧健康眼(11.07±4.53μl/min)相比,闭塞静脉中的RBF显着降低(3.51±2.25μl/min)。对于闭塞的血管,直径与速度之间的斜率为0.0195(p<0.001;r2=0.6068),直径与流量之间的关系为Q=9.91×10-6×D2.41(p<0.01;r2=0.2526)。
结论:这种AO-LDV原型为研究人类RBF和评估视网膜静脉疾病的治疗提供了新的机会。
To measure non-invasively retinal venous blood flow (RBF) in healthy subjects and patients with retinal venous occlusion (RVO).
The prototype named AO-LDV (Adaptive Optics Laser Doppler Velocimeter), which combines a new absolute laser Doppler velocimeter with an adaptive optics fundus camera (rtx1, Imagine Eyes®, Orsay, France), was studied for the measurement of absolute RBF as a function of retinal vessel diameters and simultaneous measurement of red blood cell velocity. RBF was measured in healthy subjects (n = 15) and patients with retinal venous occlusion (RVO, n = 6). We also evaluated two softwares for the measurement of retinal vessel diameters: software 1 (automatic vessel detection, profile analysis) and software 2 (based on the use of deep neural networks for semantic segmentation of vessels, using a M2u-Net architecture).
Software 2 provided a higher rate of automatic retinal vessel measurement (99.5 % of 12,320 AO images) than software 1 (64.9 %) and wider measurements (75.5 ± 15.7 μm vs 70.9 ± 19.8 μm, p < 0.001). For healthy subjects (n = 15), all the retinal veins in one eye were measured to obtain the total RBF. In healthy subjects, the total RBF was 37.8 ± 6.8 μl/min. There was a significant linear correlation between retinal vessel diameter and maximal velocity (slope = 0.1016; p < 0.001; r2 = 0.8597) and a significant power curve correlation between retinal vessel diameter and blood flow (3.63 × 10-5 × D2.54; p < 0.001; r2 = 0.7287). No significant relationship was found between total RBF and systolic and diastolic blood pressure, ocular perfusion pressure, heart rate, or hematocrit. For RVO patients (n = 6), a significant decrease in RBF was noted in occluded veins (3.51 ± 2.25 μl/min) compared with the contralateral healthy eye (11.07 ± 4.53 μl/min). For occluded vessels, the slope between diameter and velocity was 0.0195 (p < 0.001; r2 = 0.6068) and the relation between diameter and flow was Q = 9.91 × 10-6 × D2.41 (p < 0.01; r2 = 0.2526).
This AO-LDV prototype offers new opportunity to study RBF in humans and to evaluate treatment in retinal vein diseases.