Retinal artery occlusion in rabbit eyes using human atheroma

Previous animal models of central retinal artery occlusion using glass or latex embolic material may not simulate human disease. We have developed a rabbit model using human atherosclerotic material, which may be useful in developing embolus specific treatments, including thrombolysis or laser photodisruption. Fresh human atherosclerotic plaque was harvested from atherosclerotic human aorta by mechanical removal and suspension in normal saline. The suspension was agitated vigorously to produce small particles, which were separated into various sizes by filtration through mesh filters with specific pore sizes. The common carotid artery of the anesthetized rabbit was isolated by neck dissection and cannulated using a modified Seldinger technique. Suspensions of human atherosclerotic plaque were injected into the common carotid artery via this cannula. All animals were examined by slit lamp and fluorescein angiography before and after retinal artery occlusion. This model reliably produced retinal artery occlusion using human atherosclerotic plaque. Plaque particles less than 105 microns reliably produced branch retinal artery occlusion, while larger plaque particles less than 149 microns reliably produced central retinal artery occlusion. Sublingual nitroglycerin, at 0.1 mg/kg, intravenous verapamil, from 0.2 mg/kg to 2 mg/kg, and intracarotid urokinase given acutely in standard doses failed to cause reperfusion. This model will be very useful in the study and treatment of retinal vascular disorders as it may more closely simulate human disease over previous models using artificial embolic materials. Embolic specific treatment stategies, such as thrombolysis and laser photodisruption, may be further developed with this model.