Natural History of Ischemic Optic Neuropathy

Along with papilledema (raised intracranial pressure) and papillitis (anterior extension of optic neuritis), anterior ischemic optic neuropathy is one of the most common etiologies of disc swelling. This is particularly true in the older population where AION is the most common cause of sudden visual loss in the middle-aged and elderly population. In s pile of this, descriptions of the syndrome of anterior ischemic optic neuropathy are of extraordinarily recent vintage. Francois and others were responsible for first recognition of the nonarteritic form of Ischemic optic neuropathy and descriptions in the English language literature exist only within the last 25 years. While the importance of the syndrome has become readily recognized, our understanding of the pathophysiology and natural history which are fundamental to any rational therapeutic options remains surprisingly limited. We are particularly indebted to Dr. Hayreh for an extensive series of studies of the anatomy, physiology, and clinical mannestatlo In this disease process. While the singular importance of the posterior ciliary artery has been challenged clearly these vessels seem to play a paramount pathophysiologic role. Hayreh has collected what is essentially the only prospective study in the literature. Unanswered questions, however, remain significant. As Hayreh himself has pointed out in discussing the use of steroid therapy in 1981, 'The only way this controversy can be finally resolved Is by conducting a double-masked, randomized, therapeutic trial.