Optic nerve oligodendropenia,induced by ethambutol

Aim: to determine oligodendropenia in optic nerve of rabbit,induced by ethambutol method: ten,new zealand white,albino rabbits of either sex,6-12 month old; weighing 1- 2kg were randomly divided in to two groups comprising five animals in each. group a served as control,while group b was given ethambutol 100 mg/kg/day for four weeks. at the end of experimental period,each animal was sacrificed by using chloroform and both optic nerves were dissected out,preserved and processed; in this way,twenty optic nerve specimens (ten for each group) were collected from ten albino rabbits. results: mean number of oligodendrocytes was significantly decreased in group b (04.31±0.40) as compared to group a (10.41±01.34); p = 0.002. conclusion: ethambutol,in toxic doses,induces the death of oligodendrocytes in optic nerve,resulting into demyelination of optic nerve.