Toxic side effects of local anaesthetics on the human cornea.

The cytotoxic effects of 0.5% amethocaine (tetracaine) on the human cornea were investigated by scanning electron microscopy. The ultrastructural examination of epithelial cells showed damage of the cell membrane, rare-faction and loss of microvilli, deposits of amethocaine on the corneal surface and accelerated desquamation of superficial epithelial cells.