Topical anaesthetic and tear film stability

The effect of unpreserved topical anaesthetic on tear film stability (0.4% oxybuprocaine hydrochloride) was investigated in a double masked randomised study in 12 healthy volunteers, using a noninvasive tear film break up technique (NIBUT). It was found that the topical anaesthetic did not reduce the pre-corneal tear film stability, contrary to the electron microscopic evidence.