Objective: To compare the similarities and differences among the ocular beta-blockers. Important considerations when comparing these agents are the differences in systemic adverse effects, local tolerability, and cost.
Data source: Information was retrieved from a MEDLINE search of the English-language literature and bibliographic reviews of review articles. Index terms included beta-blockers, glaucoma, timolol, levobunolol, betaxolol, metipranolol, and carteolol.
Study selection: Emphasis was placed on eyedrop studies, as well as properly designed and executed clinical trials that assessed dosage, dosing interval, therapeutic response, adverse effects, and cost.
Data extraction: Data from several studies were evaluated according to the study design, therapeutic response, and adverse effects.
Data synthesis: Timolol maleate, levobunolol, metipranolol, and carteolol have similar effectiveness in lowering intraocular pressure; however, levobunolol and timolol gel forming solution may have an advantage of once-daily dosing. Studies have not been published comparing the clinical efficacy of timolol hemihydrate with that of other ocular beta-blockers. Metipranolol is cost effective in treating primary open-angle glaucoma; however, it has been associated with more ocular burning, stinging, and granulomatous anterior uveitis than other agents. The intrinsic sympathomimetic activity of carteolol has not yet displayed a definite advantage over the other agents in terms of optic disk perfusion and systemic adverse effects. The control of intraocular pressure with betaxolol has not always been as good as with timolol; however, betaxolol has some advantages over timolol and the other topical beta-blockers in terms of systemic adverse effects.
Conclusions: Considering cost, efficacy, and safety, timolol maleate is the recommended formulary agent because the other agents cannot consistently show an outstanding advantage.