Ocular blood flow was measured in the juxtapapillary choroid, retrolaminar optic nerve and ciliary body mesoderm using 14C-labelled iodoantipyrine with quantitative autoradiography in seven anesthetized baboons in an experimental model of cerebral and ocular ischemia induced by hemorrhagic hypotension following unilateral common carotid stenosis, with external carotid ligation. The eyes of seven baboons with unilateral common carotid occlusion were also examined histologically for evidence of structural changes. This autoradiographic method allowed measurement of blood flow in different ocular structures and a significant change was noted in the optic nerve of stenosed animals, without structural damage.