Bilateral Common Carotid Artery Occlusion in the Rat as a Model of Retinal Ischaemia

Abstract

Ocular ischaemic syndrome is a devastating eye disease caused by severe carotid artery stenosis. The purpose of the study was to develop a reliable rat model for this syndrome by means of common carotid artery occlusion and a controllable needle suture method. Adult Wistar rats were subjected to common carotid artery occlusion and sham surgery. The common carotid artery was ligated unilaterally or bilaterally with needles of different diameters, and ocular arterial filling time was examined by fluorescein fundus angiography at different time points. Haematoxylin-eosin staining of vessels and degree of stenosis were considered outcome measures. The ocular blood flow was monitored and measured by laser doppler flowmetry. Needles with a diameter of 0.4 mm were more effective in developing severe stenosis of the common carotid arteries compared with needles of other diameters. Bilateral common carotid artery occlusion was a more effective model than unilateral occlusion. The arterial filling time was significantly increased at 14 and 21 days after ligation (5.75 ± 0.45 and 6.27 ± 0.95 s, respectively) compared with arterial filling time before surgery (5.22 ± 0.64 s). The total blood flow in the sham surgery group was significantly higher than in the bilateral common carotid artery occlusion group. The fundus blood flow was statistically different between the two groups, whereas that of the anterior segment was not. In conclusion, the authors have established a rat model of ocular ischaemic syndrome via a controllable needle suture method, which was reliable up to 2-3 weeks after surgery.

Individual and temporal variability of the retina after chronic bilateral common carotid artery occlusion (BCCAO)

“…Their results are in accordance with our data [ 5 , 26 , 27 ]. Huang and colleagues analyzed the retina by means of FAG after 3 weeks of BCCAO in rats, and observed vein dilatation, increasing tortuosity and blurring of the optic disc, but only qualitatively [ 7 ].…”

Animal Models of Chronic Cerebral Hypoperfusion: From Mouse to Primate

“…In fact, cerebral hypoperfusion, induced by carotid artery stenosis [35,36], atrial fibrillation [37,38], and heart failure [39], is associated with cognitive decline in the general population [40]. Interestingly, BCAO in the rat could also be used as a model of retinal ischemia [41]. Although the optic nerve damage is strong, it has been used as a hypoperfusive subcortical VCI model.…”

“…However, this model also has some inherent limitations. For example, the visual pathway is invariably damaged by occlusion of the ophthalmic arteries [41], and Figure 1. Schema of the pathogenetic and neurobiological mechanism of subcortical vascular cognitive impairment.…”

“…For example, the visual pathway is invariably damaged by occlusion of the ophthalmic arteries [41], and this potentially compromises behavioral assessments. Furthermore, genetic studies may be hampered because of limited accessibility to molecular technologies for rats.…”

A refined model of chronic cerebral hypoperfusion resulting in cognitive impairment and a low mortality rate in rats

“…The BCM is a dry land maze test for the assessment of spatial learning and memory. 7,9,35 In this study we evaluated the delay in location of the escape cage (latency to escape box) as a means of assessing cognitive deficit after mCCAO. We performed the Barnes task on "dry land," a gray acrylic platform (122 cm in diameter), with 16 equidistant holes around the perimeter (O'Hara & Co.).…”