Indication Used to temporarily numb the front surface of the eye so that the eye pressure can be measured or a foreign body removed. Pharmacodynamics Oxybuprocaine is a local anaesthetic. It may be less irritating than tetracaine, and the onset and duration of action are similar to tetracaine. Mechanism of action Oxybuprocaine binds to sodium channel and reversibly stabilizes the neuronal membrane which decreases its permeability to sodium ions. Depolarization of the neuronal membrane is inhibited thereby blocking the initiation and conduction of nerve impulses.