Additive effect of latanoprost to the combination of timolol and dorzolamide

Purpose: To study the additive effect of latanoprost 0.005% in patients who have uncontrolled intraocular pressure (IOP) using timolol 0.5% and dorzolamide 2%. Methods: Fifty-two consecutive patients with open-angle glaucoma who were using timolol and dorzolamide and were considered to have IOP above their defined target pressure were included in this study. After a baseline diurnal tension curve (DTC) was performed, latanoprost once a day was added to the treatment, and a second DTC was performed 1 week later. Results: Five patients (9.6%) were discontinued from treatment because of side effects. The remaining 47 patients showed a significant IOP reduction of 3.1 mm Hg (16%) from a baseline of 19.3 mm Hg (mean IOP registered during DTC; P ≤ 0.0001). Seventeen patients (36.3%) showed a mean IOP reduction greater than 20%. Conclusions: Latanoprost had an additive effect when used as a third drug for patients on timolol and dorzolamide who were in need of further IOP reduction. These results suggest that latanoprost may be very effective in some patients with poorly controlled glaucoma on multiple therapy.