PurposeTo investigate the short-term intraocular pressure-lowering efficacy and safety of switching from a fixed combination of latanoprost/timolol to a fixed combination of latanoprost/carteolol.Patients and MethodsThe subjects were 30 eyes of 30 adult patients with primary open-angle glaucoma, normal-tension glaucoma, or ocular hypertension who were using a latanoprost-/timolol-fixed combination with insufficient intraocular pressure-lowering efficacy or adverse reactions. The subjects were switched from once-daily latanoprost/timolol to once-daily latanoprost/carteolol with no washout interval. Intraocular pressure, tear film break-up time, corneal epithelial defects, conjunctival hyperemia, blood pressure, and pulse rate were measured and compared before and 1 and 3 months after switching. Patients were monitored for adverse reactions at each visit, and dropouts were recorded.ResultsThe mean intraocular pressure at 1 month (15.9±3.1 mmHg) and 3 months (16.3±3.8 mmHg) was not significantly different from that at baseline (16.1±3.1 mmHg). The tear film break-up time and corneal epithelial defects were significantly improved after switching (p<0.01 and p<0.0001, respectively). There was a significant decrease in systolic blood pressure after 1 month and diastolic pressure after 3 months (p<0.05). There was no significant change in pulse rate during the study. Adverse reactions (blurred vision, blepharitis, and conjunctival hyperemia) occurred in 3 patients (10.0%). Four patients (13.3%) discontinued treatment during the 3-month study period.ConclusionA switch from a fixed combination of latanoprost/timolol to that of latanoprost/carteolol can maintain intraocular pressure and adherence with once-daily administration while improving tear film break-up time and corneal epithelial defects.