The ROCK Inhibitor Ripasudil Shows an Endothelial Protective Effect in Patients With Low Corneal Endothelial Cell Density After Cataract Surgery

PURPOSE: In the field of regenerative medicine, Rho kinase inhibitors (ROCK inhibitors) show a protective effect on the corneal endothelium and promote effective healing in acute surgical wounds. In this study, we investigated the effectiveness of eyedrops containing ripasudil, a ROCK inhibitor approved in Japan for therapeutic use for glaucoma. METHODS: In this retrospective observational study, 13 glaucoma patients (16 eyes) were treated with 0.4% ripasudil eyedrops twice a day after cataract surgery. The control group comprised 13 patients (17 eyes). The averaged corneal endothelial cell density from one central and four paracentral points was <1500/mm(2) (range, 527 to 1439/mm(2)). RESULTS: The mean rate of increase in the thinnest corneal thickness one week after surgery was 1.25% in the ripasudil group, which was significantly lower than the 5.97% increase observed in the control group (P = 0.0037). The mean endothelial cell density loss 90 to 120 days after surgery, excluding bullous keratopathy patients for whom measurements were not possible was −4.5% in the ripasudil group, which was significantly lower than in control group (14.1%; P = 0.0003). CONCLUSIONS: The results suggest that ripasudil may help maintain corneal endothelial functional integrity and reduce cell loss after cataract surgery in patients with low corneal endothelial cell density, suggesting that it may be more broadly useful for protection of the corneal endothelium after intraocular surgery. TRANSLATIONAL RELEVANCE: The clinically approved ROCK inhibitor ripasudil formulated as an eye drop for glaucoma has a corneal endothelial protective effect in cataract surgery for patients with low corneal endothelial cell density.