Glaucoma is a leading cause for worldwide blindness and is characterized by progressive optic nerve damage. The etiology of glaucoma is unknown, but elevated intraocular pressure (IOP) and advanced age have been identified as risk factors. IOP reduction is the only known treatment for glaucoma. Recently, drugs that inhibit Rho associated protein kinase (ROCK) have been studied in animals and people for their ability to lower IOP and potentially treat POAG. ROCK inhibitors lower IOP through a trabecular mechanism and may represent a new therapeutic approach for the treatment of glaucoma. Ripasudil is the first Rho-kinase inhibitor ophthalmic solution developed for the treatment of glaucoma and ocular hypertension in Japan 2014. ROCK inhibition not only reduces intraocular pressure (IOP) but also increases ocular blood flow.