Additional Late-onset Ocular Hypotensive Effect of Ripasudil on Primary Open-angle Glaucoma

Purpose: Ripasudil has an additional late-onset ocular hypotensive effect after long-term administration. We evaluated this additional effect of ripasudil and associated factors in primary open-angle glaucoma (POAG). Patients and Methods: We retrospectively reviewed the clinical data of patients with POAG who newly started ripasudil medication without drug change, ocular surgery, or laser treatment. These patients were assigned to two groups: positive group with the late-onset effect and negative group without it. Eyes with a gradual decrease in intraocular pressure (IOP) after starting ripasudil were defined as late-onset positive. Multivariable logistic regression was performed to explore associated factors of this effect. Results: : We enrolled 74 eyes of 74 patients with POAG (age, 67.5 ± 10.9 years; mean deviation, -11.2 ± 5.9 dB) and followed them for 14.2 ± 5.0 months. 12 (16.2%) eyes were assigned to the positive group. Retinal nerve fibre layer (RNFL) thickness (73.4 ± 12.9 vs. 64.0 ± 9.8 μm, P = 0.04) and primary IOP (18.8 ± 4.1 vs. 15.8 ± 4.3 mmHg, P = 0.01) before starting ripasudil were higher in the positive group than in the negative group. Multivariable analyses revealed primary IOP (odds ratio [OR], 1.22; 95% confidence interval [CI], 1.01-1.48) and RNFL thickness (OR, 2.76; 95% CI, 1.15-6.63) were significantly associated with late-onset IOP decline. Conclusions: : Few patients with advanced POAG showed the late-onset IOP-lowering effect of ripasudil. Multivariable analyses suggested that patients with thicker RNFLs or higher IOPs were more likely to benefit from the additional efficacy of ripasudil.