Li He, Sampani Konstantina, Zheng Xiaoning, Papageorgiou Dimitrios P, Yazdani Alireza, Bernabeu Miguel O, Karniadakis George E, Sun Jennifer K
Division of Applied Mathematics, Brown University, Providence, RI 02912, USA.
Beetham Eye Institute, Joslin Diabetes Center, Boston, MA, USA.
R Soc Open Sci. 2020 Aug 26;7(8):201102. doi: 10.1098/rsos.201102. eCollection 2020 Aug.
Microaneurysms (MAs) are one of the earliest clinically visible signs of diabetic retinopathy (DR). Vision can be reduced at any stage of DR by MAs, which may enlarge, rupture and leak fluid into the neural retina. Recent advances in ophthalmic imaging techniques enable reconstruction of the geometries of MAs and quantification of the corresponding haemodynamic metrics, such as shear rate and wall shear stress, but there is lack of computational models that can predict thrombus formation in individual MAs. In this study, we couple a particle model to a continuum model to simulate the platelet aggregation in MAs with different shapes. Our simulation results show that under a physiologically relevant blood flow rate, thrombosis is more pronounced in saccular-shaped MAs than fusiform-shaped MAs, in agreement with recent clinical findings. Our model predictions of the size and shape of the thrombi in MAs are consistent with experimental observations, suggesting that our model is capable of predicting the formation of thrombus for newly detected MAs. This is the first quantitative study of thrombosis in MAs through simulating platelet aggregation, and our results suggest that computational models can be used to predict initiation and development of intraluminal thrombus in MAs as well as provide insights into their role in the pathophysiology of DR.
微动脉瘤（MAs）是糖尿病视网膜病变（DR）最早出现的临床可见体征之一。在DR的任何阶段，微动脉瘤都可能导致视力下降，其可能会扩大、破裂并向神经视网膜渗漏液体。眼科成像技术的最新进展能够重建微动脉瘤的几何形状并量化相应的血流动力学指标，如剪切速率和壁面剪切应力，但缺乏能够预测单个微动脉瘤内血栓形成的计算模型。在本研究中，我们将颗粒模型与连续介质模型相结合，以模拟不同形状微动脉瘤内的血小板聚集。我们的模拟结果表明，在生理相关血流速率下，囊状微动脉瘤中的血栓形成比梭形微动脉瘤更明显，这与最近的临床发现一致。我们对微动脉瘤内血栓大小和形状的模型预测与实验观察结果一致，表明我们的模型能够预测新检测到的微动脉瘤内血栓的形成。这是通过模拟血小板聚集对微动脉瘤内血栓形成进行的首次定量研究，我们的结果表明，计算模型可用于预测微动脉瘤腔内血栓的起始和发展，并深入了解它们在DR病理生理学中的作用。
