利用光学相干断层扫描血管成像(OCTA)技术观察视网膜动脉阻塞患者黄斑区视网膜血流密度与视网膜厚度的特征。

回顾性研究。收集2017年4月至2019年10月就诊于中国中医科学院眼科医院眼底病眼外伤科临床诊断为视网膜动脉阻塞32例(32只眼)患者的病例资料。其中，男性24例(24只眼)，女性8例(8只眼)；年龄40~83岁，平均年龄(62.4±12.6)岁。以患者患眼为实验组，自身健眼为对照组。应用OCTA检测并记录所有患者黄斑3 mm×3 mm区域内的浅层毛细血管层(SCL)血流密度、深层毛细血管层(DCL)血流密度及视网膜厚度；对于视网膜分支动脉阻塞患者，则检测并记录黄斑6 mm×6 mm区域的SCL血流密度和DCL血流密度。实验组与对照组黄斑区视网膜的SCL、DCL血流密度及视网膜厚度以均数±标准差表示，并采用独立样本t检验进行比较。

视网膜动脉阻塞患者OCTA影像特征主要为阻塞动脉供血区视网膜内层增厚和反射增强，外丛状层带有不同程度的增宽，黄斑区拱环破坏，毛细血管分布不均。视网膜中央动脉阻塞患者22例(22只眼)，占68.8%(22/32)；视网膜分支动脉阻塞患者10例(10只眼)，占31.2%(10/32)，均为颞侧分支动脉阻塞。实验组和对照组黄斑3 mm×3 mm区域内的SCL总体血流密度分别为(40.00±5.74)%和(45.12±5.59)%；DCL总体血流密度分别为(41.16±5.86)%和(48.85±3.89)%。实验组均低于对照组，经t检验，差异有统计学意义(t＝-3.539，-5.457；P<0.05)。实验组和对照组中心凹区的SCL血流密度分别为(21.28±9.55)%和(19.10±4.76)%；DCL血流密度分别为(31.06±7.70)%和(29.14±6.43)%。实验组中心凹区的SCL和DCL血流密度均高于对照组的有14例(14只眼)，占43.8%(14/32)。黄斑6 mm×6 mm区域内，视网膜分支动脉阻塞患者患眼中心凹周边区的SCL和DCL血流密度分别为(42.24±4.64)%和(41.02±5.71)%。患眼SCL和DCL血流密度低于健眼者，均占80%(8/10)；患眼颞侧中心凹周边区的SCL和DCL血流密度低于健眼者，分别占90%(9/10)和100%(10/10)。实验组和对照组视网膜总体厚度的比较，差异无统计学意义(t＝0.224，P>0.05)。

OCTA检查可量化视网膜动脉阻塞患者的视网膜血流密度及视网膜厚度，可以为视网膜动脉阻塞患者提供客观的检查依据。

The aim of this study was to observe clinically macular vascular density and retinal thickness in retinal arterial obstruction patients with optical coherence tomography angiography (OCTA).

A retrospective study was conducted. 32 patients (32 eyes) with retinal artery obstruction were involved in this study. 24 patients (24 eyes) were male while 8 patients (8 eyes) were female, with age ranging from 40 to 83 and an average age at (62.4±12.6). The sick eyes were divided into test group while their own healthy eyes as the control group. OCTA was performed among all the patients. The superficial capillary layer (SCL) vascular density, the deep capillary layer (DCL) vascular density and the retinal thickness within 3 mm×3 mm area of the macular were recorded with OCTA. SCL and DCL vascular density within 6 mm×6 mm area were also recorded in branch retinal artery occlusion patients. SCL, DCL and retinal thickness were represented as mean±standard deviation. Independent samples t test was conducted for data comparison.

The main characteristics of retina artery occlusion on OCTA were thickening and enhanced reflex of inner layer of the retina, widened outer plexiform zone, destroyed fovea avascular zone, and distribution of capillaries. 22 patients (22 eyes) accouting for 68.8% (22/32), were central retinal artery occlusion patients. 10 patients (10 eyes) accouting for 31.2% (10/32), were branch retinal artery occlusion patients, with temporal branch retinal artery occlusion. SCL total vascular density in 3 mm×3 mm of the macular of the test group and control group were (40.00±5.74)% and (45.12±5.59)%, respectively. While DCL total vascular density in 3 mm×3 mm of the macular of the test group and control group were (41.16±5.86)% and (48.85±3.89)%, respectively. The vascular densities both in SCL and DCL were lower in test group with the significant differences between them through t test analysis(t=-3.539, -5.457; P<0.05). SCL fovea vascular density of the test group and control group were (21.28±9.55)% and (19.10±4.76)% , respectively. While DCL fovea vascular density of the test group and control group were (31.06±7.70)% and (29.14±6.43)%, respectively . Higher fovea vascular densities both in SCL and DCL were found in 14 patients (14 eyes) accouting for 43.8% (14/32). SCL and DCL perifovea vascular density in 6 mm×6 mm of the macular were (42.24±4.64)% and (41.02±5.71)%, respectively in sick eyes of branch retinal artery occlusion patients, among which lower vascular densities than the healthy eyes were found in 80% (8/10) patients. Lower temporal perifovea vascular densities in SCL and DCL were found in 90% (9/10) and 100% (10/10) patients, respectively. There was no significant difference between test group and control group in total retinal thickness (t=0.224, P>0.05).

OCTA could quantify retinal vascular density and retinal thickness in retinal artery occlusion patients, providing objective examination outcomes.