Add-on Effect of Prostaglandin Analogues in Dorzolamide/Timolol Fixed Combination Treated Primary Open Angle Glaucoma Patients

Purpose: To evaluate the additive intraocular pressure (IOP)-lowering effect of three different prostaglandin analogues in dorzolamide/timolol fixed combination (DTFC)-treated primary open angle glaucoma (POAG).Methods: In this retrospective chart review, adjunctive latanoprost, travoprost, or bimatoprost were administered in DTFC-treated POAG patients who required additional IOP-lowering treatment. IOP, mean deviation value, and adverse drug reactions (ADRs) were evaluated.Results: In the latanoprost group, the baseline IOP was 22.1 ± 1.3 mmHg. The mean IOP after 12 months of adjunctive latanoprost was 18.6 ± 1.3 mmHg and the reduction rate was 15.8% (p = 0.000). In the travoprost group, the mean IOP after adjunct travoprost was 18.2 ± 1.5 mmHg and the reduction rate was 16.9% (p = 0.000). In the bimatoprost group, the mean IOP and reduction rate were 18.1 ± 1.5 mmHg and 17.0%, respectively (p = 0.000). There were no significant differences in the additional IOP reduction rate among the three groups (p = 0.687). The most common ADR was conjunctival hyperemia in all three groups. However, there were no serious ADRs causing ocular damage.Conclusions: Latanoprost, travoprost, and bimatoprost showed additional IOP reduction by 15.8-17.0% in DTFC-treated POAG patients.