A 90-day study of the efficacy and side effects of 0.25% and 0.5% apraclonidine vs 0.5% timolol. Apraclonidine Primary Therapy Study Group.

OBJECTIVE

To compare long-term intraocular pressure (IOP)-lowering efficacy of 0.25% and 0.5% apraclonidine hydrochloride with 0.5% timolol maleate.

DESIGN

Multicenter, randomized, double-masked trial. Adult patients of either sex diagnosed as having open-angle glaucoma or ocular hypertension were enrolled following appropriate washout from all ocular hypotensive medications. Morning IOPs of 22 to 35 mm Hg were required for entry. Patients received 0.25% or 0.5% apraclonidine 3 times a day or 0.5% timolol twice a day for 90 days. Intraocular pressure was measured at 8 AM (before morning dosing) and at 4 PM (8 hours after dosing) on days 1, 30, and 90, and only at 8 AM on day 14.

RESULTS

All 3 medications significantly reduced IOP from baseline at all observation times (P < .001): 0.5% apraclonidine reduced IOP more than 0.25% apraclonidine; no significant difference was observed between 0.5% apraclonidine and 0.5% timolol 8 hours after dosing on days 1, 30, and 90; and a significant difference (P < .05) in favour of 0.5% timolol over 0.25% apraclonidine was observed 8 hours after dosing on day 30. At all morning visits following evening dosing, 0.5% timolol significantly reduced IOP more than both concentrations of apraclonidine.

CONCLUSIONS

Both 0.25% and 0.5% apraclonidine significantly reduce IOP when used as primary ocular hypotensive medication. Although 0.25% and 0.5% apraclonidine reduce IOP to a similar degree as 0.5% timolol 8 hours after morning dosing, neither concentration is as effective for reducing morning IOP after evening dosing.