Cavernous optic atrophy of Schnabel is characterized microscopically by large cystic spaces containing mucopolysaccharide material, which stains with alcian blue, posterior to the lamina cribrosa. The intracystic material that penetrates into the parenchyma through the internal limiting membrane of the optic nerve head is thought to be vitreous. These changes occur most commonly in patients with glaucoma after acute IOP elevation, but they have also been seen in nonglaucomatous elderly patients with generalized arteriosclerotic disease