Conjunctival keratinisation, an abnormal reaction to an ocular beta-blocker.

Conjunctival leucoplakia was induced by the local beta-blocker metipranolol in one case. Withdrawal of the drug and application of all-trans retinoic acid ointment resulted in resolving of the keratinisation. A striking pharmacological resemblance is discovered between metipranolol and practolol. Metipranolol seems to be a less toxic phenol derivative of practolol. Nevertheless, it seems able to act as antigen.