Methylene dianilene: a new toxic cause of visual failure with hepatitis.

A 28-year-old man ingested methylene dianilene in potassium carbonate and gamma-butyrolactone. He developed toxic optic neuritis, with severe visual dysfunction (not previously reported in humans), prolonged toxic hepatitis, with disturbed liver-function tests 18 months after the incident, and other more transient effects. The course of his illness is described and the literature on methylene dianilene toxicity is reviewed.