Early ultrastructural findings and superoxide dismutase levels in experimental ischemic optic neuropathy: Effect of hypertension and hypotension on ischemic changes

We induced ischemia, hypertension and hypotension in 15 rabbits in order to evaluate the ischemic changes in the optic nerve and the effect of hyperte nsion and hypotension on ischemia. We cauterized the right internal and ext ernal carotid arteries of 15 rabbits and applied dopamine hydrochloride and glycerol trinitrate to 5 each of these rabbits. Two rabbits were used as c ontrols, We enucleated both eyes of all animals at the 24th hour. All of th e optic nerves underwent biochemical, histopathological and ultrastructural examination. Histopathological and transmission electron-microscopic chang es were found to be more prominent in the hypotensive group, We observed de creased superoxide dismutase levels in all groups, but it was more evident in the third group, In comparison to hypertension, hypotension is found to be a more important factor in the development of early degenerative changes . Copyright (C) 2001 S. Karger AG.,Basel.