Ripasudil in a Model of Pigmentary Glaucoma

Purpose: To investigate the effects of Ripasudil (K-115), a Rho-kinase inhibitor, in a porcine model of pigmentary glaucoma. Methods: In vitro trabecular meshwork (TM) cells and ex vivo perfused eyes were subjected to pigment dispersion followed by K-115 treatment (PK115). PK115 was compared to controls (C) and pigment (P). Cytoskeletal alterations were assessed by F-actin labeling. TM cell phagocytosis of fluorescent targets was evaluated by flow cytometry. Cell migration was studied with a wound-healing assay. Intraocular pressure was continuously monitored and compared to after the establishment of the pigmentary glaucoma model and after treatment with K-115. Results: The percentage of cells with stress fibers increased in response to pigment but declined sharply after treatment with K-115 (P: 32.8% +/- 2.9%; PK115: 11.6% +/- 3.3%, P < 0.001). Phagocytosis first declined but recovered after K-115 (P: 25.7% +/- 2.1%, PK115: 33.4% +/- 0.8%, P <0.01). Migration recuperated at 12 hours with K-115 treatment (P: 19.1 +/- 4.6 cells/high-power field, PK115: 42.5 +/- 1.6 cells/high-power field, P < 0.001). Ex vivo, eyes became hypertensive from pigment dispersion but were normotensive after treatment with K-115 (P: 20.3 +/- 1.2 mm Hg, PK115: 8.9 +/- 1.7 mm Hg; P < 0.005). Conclusions: In vitro, K-115 reduced TM stress fibers, restored phagocytosis, and restored migration of TM cells. Ex vivo, K-115 normalized intraocular pressure.