Unless.ormal circulation to the retina can be restored promptly, these cells will die within a few minutes or hours depending on how completely the blood flow is obstructed. Chronic signs include thinned retinal tissue, attenuated vessels, retinal pigment epithelial mottling, and severely decreased vision. The ERG may be normal in some cases despite poor visual acuity if the blood flow renormalizes. Medline . If the intra ocular pressure goes very high and is not controlled by the above medical regimen, then we add graduated cyclocryotherapy or other graduated cycloablation procedures.