Ripasudil Hydrochloride Hydrate in the Treatment of Glaucoma: Safety, Efficacy, and Patient Selection

Reduction of intraocular pressure (IOP) is the only reliable treatment for glaucoma that maintains the patient's visual function throughout life, and IOP-lowering eyedrops are the mainstay of therapy. Ripasudil hydrochloride hydrate (brand name: Glanatec ophthalmic solution 0.4%; Kowa Company, Ltd., Japan) is a Rho-associated coiled-coil-containing protein kinase (ROCK) inhibitor that lowers IOP by increasing conventional aqueous outflow. Since the approval of ripasudil eyedrops in 2014, a large store of clinical data has been amassed in Japan. With regard to safety, conjunctival hyperemia is the most common adverse drug reaction (ADR) and is usually transient and mild. Blepharitis and allergic conjunctivitis are other major local ADRs. Systemic ADRs are rare, but we should be wary of allergic reactions. With regard to efficacy, ripasudil is expected to lower IOP in almost all glaucoma subtypes (including primary open-angle glaucoma, secondary glaucoma, and primary angle-losure glaucoma) and in all patterns of treatment initiation (monotherapy, combination therapy, switching therapy, and add-on therapy). However, the status of the trabecular meshwork may affect the IOP-lowering effect of ripasudil. In patient selection, current evidence-based information on the safety and efficacy of ripasudil should be fully considered. As irreversible damage to the trabecular meshwork would considerably affect efficacy, it may be better to start ripasudil treatment during an early stage of glaucoma.