Local ocular hypotensive effect of topically applied acetazolamide.

Acetazolamide's usefulness in the treatment of the glaucomas is limited by the systemic side effects that often accompany its oral administration, and topical administration was initially thought to have no effect upon the intraocular pressures of human and rabbit eyes. Recent studies, however, have shown the usefulness of water-loading tests for screening drugs with potential antiglaucomatous activity. We found evidence that topical acetazolamide has the ability to lessen the increase in intraocular pressure after water-loading in pigmented rabbits and correlated this observation with low levels (0.0 to 0.7 microgram/ml) of plasma acetazolamide. Further, a separate study showed that 10% topical acetazolamide can enhance the ocular hypotensive effects of systemically administered acetazolamide in normal pigmented rabbits, suggesting that topically applied acetazolamide can have a local effect on intraocular pressure.