Functional and morphologic study of retinal hypoperfusion injury induced by bilateral common carotid artery occlusion in rats

Yali Qin,Dan Luo,Tingting Deng,Ming Jin,Yingxin Zi,Meiqi Ji,Zhijun Wang,Lin Pan

doi:10.1038/s41598-018-36400-5

Abstract

Retinal hypoperfusion injury is the pathophysiologic basis of ocular ischemic syndrome (OIS) which often leads to severe visual loss. In this study, we aimed to establish a rat model of retinal chronic hypoperfusion by bilateral common carotid artery occlusion (BCCAO) and observe changes in the retinal function and morphology. We found that model rats showed retinal arteriosclerosis, slight dilated retinal vein, small hemangiomas, hemorrhages, vascular segmental filling, and nonperfused areas after 2 weeks of BCCAO. In the model rats, the retinal circulation time was significantly prolonged by fluorescein fundus angiography (FFA), the latency of a and b waves was delayed and the amplitude was decreased significantly at each time point by electroretinogram (ERG), and the perfusion of the eyes continued to reduced. Morphologic and ultrastructural changes covered that the retinal ganglion cells (RGCs) presented obvious apoptosis and the thickness in the retinal layers were significantly thinner. Collectively, these findings suggested that BCCAO induced retinal hypoperfusion injury in the model rats, thus providing an ideal animal model for the study of OIS.

Highlights

Retinal hypoperfusion injury is an ocular circulatory disorder caused by carotid artery stenosis or occlusion
Bilateral common carotid artery occlusion (BCCAO) is a method of inducing chronic ocular ischemia; it has gradually been accepted in recent years because its pathological process mimiced clinical ocular ischemic syndrome (OIS) caused by carotid artery stenosis or obstruction[12,13]
One BCCAO rat died at the second week and two BCCAO rats died at the fourth week

Summary

Introduction

Retinal hypoperfusion injury is an ocular circulatory disorder caused by carotid artery stenosis or occlusion. It belongs to the category of ocular ischemic syndrome and is often associated with ischemic encephalopathy. The establishment of an ideal experimental model of ocular ischemia and exploratory study of its characteristics and mechanisms are of significant importance for the clinical diagnosis and treatment of OIS. Bilateral common carotid artery occlusion (BCCAO) is a method of inducing chronic ocular ischemia; it has gradually been accepted in recent years because its pathological process mimiced clinical OIS caused by carotid artery stenosis or obstruction[12,13]. Chronic retinal hypoperfusion injury models were established by bilateral common carotid artery occlusion. The retinal functional and morphologic changes were systematically compared and studied during different observation periods and at different sites

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Conclusion