OPTIC NERVE DISEASES
Toxic Optic Neuropathy
Toxic optic Neuropathy is an optic nerve lesion resulting from exposure to systemic medications or environmental toxins.
The clinical picture is characterized by a progressive, insidious and painless bilateral loss of central vision.
Initially, ophthalmic examination may be characterized by a paucity of clinical signs. There may be a mild depression of central retinal sensitivity, progressing to a more severe difuse visual loss with decreased visual acuity, dyschromatopsia, and central or cecocentral scotoma. If the offending agent is not identified and suspended, optic atrophy eventually ensues.
The most common pharmacological offending agents are: ethambutol, isoniazid, chloramphenicol, penicillamine, cysplatin and vincristine. Environmental toxins include: methanol, ethylene glycol and heavy...