There are sarcomatous globes in which instead of an attack of ordinary glaucoma there is a sudden outbreak of extremely severe iridocyclitis which may lead to atrophy of the organ. Anatomic examination in such instances reveals that the tumor has become necrotic. The necrosis is due to deficient nutrition, as the new blood vessels are large and there are no capillaries. The cells, which gain their nourishment by osmosis, perish when they are too far away from the blood supply. As a result of the death of the cells cytotoxins are developed which in themselves have a necrotizing influence on the tissues of the globe. The ciliary body, the iris and the cornea above all are affected.
In order to understand the important rôle that necrosis and toxins may play in the pathologic and clinical pictures of a sarcoma of the choroid one should bear in mind the