What is the primary use of oral CAIs?

• A. Rapid lowering of very high IOP and short-term use for high IOP when max topical medications are used
• B. Long-term control of IOP
• C. First-line therapy for all glaucoma
• D. To replace topical medications completely

Answer: (A)

Oral carbonic anhydrase inhibitors work by systemically reducing aqueous humor production, which makes their effect on lowering IOP rapid. Because this class acts quickly but carries more systemic side effects, it’s best suited for short-term, urgent reductions in very high IOP—such as in acute situations or as a bridge when maximal topical therapy hasn’t brought the pressure down yet. They’re not intended for long-term control due to risks like metabolic acidosis, electrolyte disturbances, kidney stones, and other systemic effects, and they can’t replace topical medications in routine glaucoma management.