Abstract
The theoretical possibility of extending the effective choroidal oxygen diffusion gradient to supply ischemic inner retinal layers following retinal arterial occlusion is investigated. The feasibility of this concept is demonstrated in the adult cat and monkey breathing oxygen at hyperbaric pressures following sudden occlusion of the retinal circulation. Two methods of producing an experimental model of retinal arterial occlusion xoere used in this study. One consisted of the reduction of the net ocular perfusion pressure by raising intraocular pressure to a level at which retinal blood flow stopped. This model, however, also included a simultaneous reduction in choroidal blood flow. The second, experimental model consisted of argon laser photocoagulation of retinal arteries near the edge of the disc; in this model, choroidal circulation was left essentially intact. Changes in the stabilized, electroretinographic response were used as indicators of retinal tissue viability during experiments. Similar results were obtained using both experimental models of retinal arterial occlusion.