Abstract

Acetazolamide is a carbonic anhydrase inhibitor which is on World Health Organization’s list of essential medicines, a list of most important medications needed in a basic health system. The ocular effects of acetazolamide was studied in 30 normotensive volunteers. Each volunteer received a loading dose of 500 mg at 0700 h followed by a maintenance dose of 250 mg at 1300 and 1800 h, respectively on day one. From day two to day five, the volunteers received 250 mg acetazolamide thrice daily at the established time intervals. Each volunteer served as his or her own control. Ocular effects of the drug were assessed on the following visual functions; pupil diameter, near point of convergence, visual acuity, amplitude of accommodation, accommodation/convergence accommodation ratio and the phoria status. Results showed that the pupil diameter and near point of convergence increased while the amplitude of accommodation and the accommodation/convergence accommodation ratio decreased. The phoria tended towards exophoria. The aggregate effect on the volunteers was convergence insufficiency with the accompanying asthenopic symptoms, transient myopia and photophobia.

Key words: Acetazolamide, asthenopic, symptoms, convergence, insufficiency.