Ocular blood flow and choroidal thickness changes after carotid artery stenting

ABSTRACT Purposes: To evaluate changes in ocular blood flow and subfoveal choroidal thickness in patients with symptomatic carotid artery stenosis after carotid artery stenting. Methods: We included 15 men (mean age, 63.6 ± 9.1 years) with symptomatic carotid artery stenosis and 18 healthy volunteers (all men; mean age, 63.7 ± 5.3 years). All participants underwent detailed ophthalmologic examinations including choroidal thickness measurement using enhanced depth-imaging optic coherence tomography. The patients also underwent posterior ciliary artery blood flow measurements using color Doppler ultrasonography before and after carotid artery stenting. Results: Patients lacked ocular ischemic symptoms. Their peak systolic and end-diastolic velocities increased to 10.1 ± 13.1 (p=0.005) and 3.9 ± 6.3 (p=0.064) cm/s, respectively, after the procedure. Subfoveal choroidal thicknesses were significantly thinner in patients with carotid artery stenosis than those in the healthy controls (p=0.01). But during the first week post-procedure, the subfoveal choroidal thicknesses increased significantly (p=0.04). The peak systolic velocities of the posterior ciliary arteries increased significantly after carotid artery stenting (p=0.005). We found a significant negative correlation between the mean increase in peak systolic velocity values after treatment and the mean preprocedural subfoveal choroidal thickness in the study group (p=0.025, r=-0.617). Conclusions: In patients with carotid artery stenosis, the subfoveal choroid is thinner than that in healthy controls. The subfoveal choroidal thickness increases after carotid artery stenting. Carotid artery stenting treatment increases the blood flow to the posterior ciliary artery, and the preprocedural subfoveal choroidal thickness may be a good predictor of the postprocedural peak systolic velocity of the posterior ciliary artery.摘要 研究目的：评估有症状颈动脉狭窄（symptomatic carotid artery stenosis）患者在接受颈动脉支架置入术（carotid artery stenting）后，眼部血流量及黄斑下脉络膜厚度（subfoveal choroidal thickness）的变化。 研究方法：本研究纳入15例男性有症状颈动脉狭窄患者（平均年龄63.6±9.1岁）及18名健康男性志愿者（平均年龄63.7±5.3岁）。所有受试者均接受全面眼科检查，包括采用增强深度成像光学相干断层扫描（enhanced depth-imaging optic coherence tomography）测量脉络膜厚度。患者分别于颈动脉支架置入术前后，采用彩色多普勒超声（color Doppler ultrasonography）检测睫状后动脉（posterior ciliary artery）血流量。 研究结果：所有患者均未出现眼部缺血症状。术后收缩期峰值流速及舒张末期流速分别升至10.1±13.1 cm/s（p=0.005）与3.9±6.3 cm/s（p=0.064）。颈动脉狭窄患者的黄斑下脉络膜厚度显著低于健康对照组（p=0.01）。但在术后第一周，黄斑下脉络膜厚度出现显著升高（p=0.04）。颈动脉支架置入术后，睫状后动脉的收缩期峰值流速显著升高（p=0.005）。本研究组中，治疗后收缩期峰值流速的平均增幅与术前黄斑下脉络膜平均厚度呈显著负相关（p=0.025，r=-0.617）。 研究结论：颈动脉狭窄患者的黄斑下脉络膜厚度低于健康对照人群。颈动脉支架置入术后，患者的黄斑下脉络膜厚度升高。颈动脉支架置入术可增加睫状后动脉血流量，术前黄斑下脉络膜厚度或可作为术后睫状后动脉收缩期峰值流速的良好预测指标。