The Experimental Study Of Anterior Ischemic Optic Neuropathy

Purpose: Anterior Ischemic Optic Neuropathy (AION) is a common ocular fundus deasease. Now there are mang therapeutic interventions for AION , but the effectiveness of the treatment may be undercut. AION is caused by sudden loss of vascular supply to retinal ganglion cell (RGC) axons in the anterior portion of the optic nerve and is a major cause of optic nerve dysfunction. There has been no easily obtainable animal model of this disorder. We design a novel model of rodent AION(rAION) to enable more detailed study of this disease. It may be useful in dertermining possible therapeutic interventions for this disorder.Methods : We develop ped a novel photothrombosis-induced rat model of AION (rAION). Thirty male Sprague-Dawley rats were randomly divided into group Naive with 5 rats, group Laser with 5 rats, group hematoporphyrin derivative(HPD) with 5 rats, group rAION with 15 rats.All of the right eyes were the experimental eyes and the left ones were the control, after administration of HPD in rats vena caudalis, the rat was directly treated with a krypton red 647nm/2/3 disc spot laser for 120 seconds in group rAION, the rats in group Laser were treated with a krypton red 647nm/2/3disc spot laser for 120 seconds, the rats in group HPD were treated by administration of HPD in rats vena caudalis, the rats in group Naive were not treated. In contrast , we are sure that it is photochemical reaction .rather than direct thermal damage or HPD cellular toxicity, results in sudden loss of vascular supply to retinal ganglion cell (RGC) axons in the anterior portion of the optic' nerve. The rAION model is thus directly analogous to human AION. We used this method to determine the in vivo RGC and ON response to rAION, without significant intraretinal damage or disturbance of underlying retinal structures. Using fundus fluorescein angiography(FFA), histologic, electrophysiological methods, the early changes associated with isolated RGC...