Additive effects and safety of fixed combination therapy with 1% brinzolamide and 0.5% timolol versus 1% dorzolamide and 0.5% timolol in prostaglandin-treated glaucoma patients

Abstract

Purpose: To compare the additive effects and safety of 1% brinzolamide/0.5% timolol fixed combination (BTFC) versus the low-dose regimen of 1% dorzolamide/0.5% timolol fixed combination (DTFC) in patients with open-angle glaucoma and ocular hypertension (OAG/OH) following treatment with prostaglandin analogues (PGAs).

Methods: A prospective, randomized, double-masked, multicentre, parallel-group and active-controlled study included 201 Japanese OAG/OH patients who had been treated with PGA. Efficacy was assessed as the change in intra-ocular pressure (IOP) from baseline after weeks 4 and 8. Safety was assessed with adverse event rates, ocular discomfort score, blur scale, blood pressure and heart rates, best-corrected visual acuity (BCVA) and slit lamp examinations.

Results: Intra-ocular pressure (IOP) change from baseline at 9 AM/11 AM pooled over the 8 weeks was -3.3/-3.3 mmHg in the BTFC group and -2.9/-3.4 mmHg in the DTFC group, demonstrating non-inferiority of BTFC to DTFC. Ocular irritation was frequently seen in DTFC group. Although blurred vision was frequently seen in BTFC group, it was transient and blurring became the equivalent 3 min after instillation between two groups. No noteworthy issue was observed in other safety outcome.

Conclusion: Non-inferiority of BTFC to DTFC in IOP reduction was demonstrated after adding onto PGA therapy in Japanese OAG/OH patients. Although the score of blurred vision was transiently higher in BTFC than DTFC, treatment difference decreased and disappeared with time. Thus, BTFC can be considered as a safe and effective agent for glaucoma treatment.

Keywords: brinzolamide; dorzolamide; fixed combination; glaucoma; intra-ocular pressure.