Efficacy and side effects of latanoprost monotherapy compared to adding dorzolamide to timolol in patients with glaucoma and ocular hypertension--a three-month randomised study. Spanish Latanoprost Study Group.

PURPOSE: To compare the efficacy and safety of latanoprost monotherapy or dorzolamide and timolol in glaucoma patients inadequately controlled on adrenergic beta-receptor antagonist therapy.

METHODS

A total of 164 patients with primary open-angle glaucoma, capsular glaucoma or ocular hypertension were included in a three-month, open-label, randomised multicentre study. Patients with open-angle glaucoma were required to have IOP at least 22 mmHg and patients with ocular hypertension were required to have IOP at least 27 mmHg, on treatment with one or two ocular hypotensive drugs of which at least one had to be a beta-blocker. All patients were treated with timolol, 5 mg/ml twice daily, for a 2-4 week run-in period. They were then randomised to latanoprost, 50 microg/ml once daily, or timolol 5 mg/ml plus dorzolamide, 20 mg/ml twice daily. The difference in mean diurnal IOP change from baseline to month 3 was compared in the two groups.

RESULTS

When patients were switched to latanoprost, mean diurnal IOP was reduced by 5.2 mmHg (23%) compared to 4.0 mmHg (17%) in the group in which dorzolamide was added to timolol. The difference of 1.2 mmHg was statistically significant (p = 0.005). The majority of adverse events during both treatments were judged as mild.

CONCLUSIONS

The results suggest that a switch to latanoprost monotherapy is an alternative to combined treatment with timolol and dorzolamide in patients inadequately controlled on a topical adrenergic beta-receptor antagonist alone.