Long-term intraocular pressure after switching a combination ophthalmic medication of β-blocker/prostaglandin

PURPOSE: We examined intraocular pressure (IOP)-reducing effects 12 months after switching timolol maleate/travoprost combination ophthalmic solution in one bottle (TM/TR-COMBI-SOL) to carteolol hydrochloride/latanoprost combination ophthalmic solution in one bottle (CR/LT-COMBI-SOL). CASES: The participants included 25 patients (25 eyes) who could be followed up for 12 months after a switch from TM/TR-COMBI-SOL to CR/LT-COMBI-SOL in Saiseikai Arida Hospital between March 1, 2017, and August 31, 2018. They consisted of patients in whom antiglaucoma eye drop other than TM/TR-COMBI-SOL had not been used (monotherapy group, 12 patients [12 eyes], 12.8 ± 3.0 mmHg) and those in whom antiglaucoma eye drop other than TM/TR-COMBI-SOL had been concomitantly used (multitherapy group, 13 patients [13 eyes], 13.8 ± 2.4 mmHg). We excluded patients in whom drugs for glaucoma were changed or added during the follow-up and those who underwent intraocular surgery. MATERIALS AND METHODS: We retrospectively and statistically examined the IOP before eye drop switching and after 1, 6, and 12 months, using the paired t-test. RESULTS: The IOPs 1 month after eye drop switching in the monotherapy group and multitherapy group were 12.5 ± 3.3 and 13.8 ± 2.5 mmHg, respectively. The values after 6 months were 13.5 ± 3.0 and 11.5 ± 2.7 mmHg, respectively. Those after 12 months were 12.8 ± 2.7 and 11.7 ± 2.5 mmHg, respectively. In the monotherapy group, there was no significant difference during the follow-up period. In the multitherapy group, there were significant decreases in comparison with the preswitching value after 6 and 12 months (P < 0.05, respectively). CONCLUSION: The IOP-reducing effects of CR/LT-COMBI-SOL were similar to those of TM/TR-COMBI-SOL. However, the effects may be enhanced after switching from TM/TR-COMBI-SOL in patients receiving multitherapy.