Comparison of ocular hypotensive effects of acetazolamide and atenolol

The ocular hypotensive effect of single oral doses of (a) atenolol (50 mg), (b) acetazolamide (500 mg), (c) atenolol (50 mg) and acetazolamide (500 mg) in combination, and (d) vehicle (inert tablets) were compared in 8 patients with glaucoma. In this single-dose, double-masked trial the combination was observed as most effective in reducing ocular tension. Both the combination and atenolol performed markedly better than vehicle. That acetazolamide did not reduce ocular tension significantly more than vehicle is probably explained by relatively low initial ocular tensions. There was no evidence of interaction between atenolol and acetazolamide in this study. Acetazolamide probably remains the first-choice oral medication for glaucoma. It is cautiously suggested that beta-blocking drugs may have a future therapeutic role, but longer-term studies on larger numbers will be required to establish this.