Optic Nerve Head Blood Flow Changes Induced by Ripasudil Added to Prostaglandin Analogues in Primary Open Angle Glaucoma

Purpose: To evaluate the effect of topical ripasudil, a Rho-associated-kinase inhibitor, added to prostaglandin analogue eye drops on optic nerve head (ONH) blood flow in patients with primary open angle glaucoma (POAG). Subjects and Methods: Subjects comprised 12 eyes from 12 patients with POAG who had been using a topical prostaglandin analogue for more than 3 months. ONH blood flow, intraocular pressure (IOP), blood pressure and pulse rate were measured before and 2 months after the treatment with a prostaglandin analogue and 0.4% ripasudil or 0.5% timolol in a randomized crossover study using the envelope method. ONH rim blood flow was assessed using laser speckle flowgraphy. Results: The addition of 0.4% ripasudil or 0.5% timolol to the prostaglandin analogue significantly decreased IOP by the same degree. There was no correlation between changes of ocular perfusion pressure and ONH blood flow. Analysis of blood flow in 4 sections of the ONH rim showed that the combined treatment with a prostaglandin analogue and ripasudil, but not timolol, significantly increased ONH blood flow in all sections except for the temporal section. Conclusions: The present study indicates that short-term treatment with ripasudil, added to a prostaglandin analogue, increases ONH blood flow probably due to its vasodilator action.