Koutsiaris Aristotle G, Riri Konstantina, Boutlas Stylianos, Panagiotou Thomas N, Kotoula Maria, Daniil Zoe, Tsironi Evangelia E
Medical Informatics Laboratory, Faculty of Medicine, School of Health Sciences, University of Thessaly, Biopolis, Larissa, Greece.
Department of Ophthalmology, University Hospital of Larissa, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece.
Clin Hemorheol Microcirc. 2022;82(4):379-390. doi: 10.3233/CH-221554.
BACKGROUND & OBJECTIVE: To quantify the hemodynamic and thrombotic effect of COVID-19 on the eye microcirculation of patients with thromboprophylaxis, shortly after hospital discharge.
This case-control study included 17 COVID-19 survivors (named "COVID-19 Group") and 17 healthy volunteers (named "Control Group"). Axial blood velocity (Vax) and percentage of occluded vessels (POV) were quantified by Conjunctival Video Capillaroscopy (CVC). Microvessels were identified and classified as "capillaries" (CAP), "postcapillary venules of size 1" (PC1), and "postcapillary venules of size 2" (PC2).
The COVID-19 Group did not differ significantly in basic demographics from the Control Group. In the COVID-19 Group, there was a statistically significant (p < 0.001) reduction of Vax (39%, 49% and 47%, for CAP, PC1, and PC2, respectively) in comparison to the Control Group and a sizeable (p < 0.001) increase of POV (600%) in comparison to the Control Group.
COVID-19 not only reduces significantly axial blood velocity in the capillaries and postcapillary venules of the eye but has also a devastating effect on microthrombosis (POV) despite thromboprophylaxis treatment. This gives a possible explanation for long COVID and a hint about the existence of a possibly unknown coagulation factor.
为了量化新冠病毒病（COVID-19）在出院后不久对接受血栓预防治疗的患者眼部微循环的血流动力学和血栓形成影响。
本病例对照研究纳入了17名COVID-19康复者（称为“COVID-19组”）和17名健康志愿者（称为“对照组”）。通过结膜视频毛细血管镜检查（CVC）对轴向血流速度（Vax）和血管闭塞百分比（POV）进行量化。微血管被识别并分类为“毛细血管”（CAP）、“1级毛细血管后微静脉”（PC1）和“2级毛细血管后微静脉”（PC2）。
COVID-19组与对照组在基本人口统计学特征上无显著差异。在COVID-19组中，与对照组相比，Vax有统计学显著降低（CAP、PC1和PC2分别降低39%、49%和47%，p<0.001），与对照组相比，POV有相当大的增加（600%，p<0.001）。
COVID-19不仅显著降低眼部毛细血管和毛细血管后微静脉的轴向血流速度，而且尽管进行了血栓预防治疗，但对微血栓形成（POV）仍有破坏性影响。这为长期新冠提供了一种可能的解释，并暗示了可能存在一种未知的凝血因子。
