An experimental model of carotid artery occlusive disease.

To develop an animal model for acute carotid artery occlusion suitable for studying the retinal sequelae of this disease, we performed bilateral and unilateral common carotid artery ligations on mature pigmented rats. Bilateral ligation consistently resulted in a characteristic pathologic retinal appearance, paralleling the retinopathy of carotid artery occlusive disease in humans, demonstrated by fundus photography and fluorescein angiography. Any abnormalities found in the rats with unilateral ligations were inconsistent and less severe, although fluorescein angiography proved to be more sensitive than ophthalmoscopy for detecting these subtle changes. Pepsin-trypsin retinal digests disclosed extensive disruption of the microvasculature in the eyes of bilaterally ligated animals. This model should prove to be useful in examining the reversibility of the ocular findings as well as evaluating central nervous system abnormalities after carotid artery occlusion.