Fig. 1. Anterior view montage of a cynomolgus monkey ocular casting with Tenon's and episcleral vessels removed. The anterior ciliary arteries (ACA) arborize at the limbus and interconnect via their lateral branches to form the episcleral circle. (CM, ciliary muscle capillary bed; CV, choroidal veins; EC, episcleral circle. (Original magnification, X20). (Morrison JC, van Buskirk EM: Anterior collateral circulation in the primate eye. Ophthalmology 90:707, 1983)