Introduction
In a previous study1 evidence was produced that systemic administration of iodoacetic acid (IAA) and ionizing radiation, when administered to the eye only, elicit very similar ocular lesions. The clinical and histological changes produced by these two different agents in the lens and retina of rabbits correlate surprisingly well. However, there were some significant differences observed with regard to the latent periods of the exudative changes in the aqueous humor and vitreous (Table 1). The exudation appeared somewhat earlier after irradiation than after IAA. The most puzzling feature, however, was presented by the fact that the leading cell type in the exudate of irradiated eyes consisted of polymorphonucleocytes, whereas the exudate in the eyes of IAA-treated animals was dominated by red blood cells. Such a difference in the exudative manifestations was difficult to understand and certainly was in contradiction to the commonly favored view that both IAA and