Oral Administration of Cilostazol Increases Ocular Blood Flow in Patients with Diabetic Retinopathy

PURPOSE: To investigate the effect of cilostazol on ocular hemodynamics and to determine whether the administration of cilostazol increases the ocular blood flow in patients with diabetic retinopathy. METHODS: This prospective observational study investigated the effect of orally administered cilostazol on diabetic retinopathy. Before and after administration for 1 week, pulsatile ocular blood flow (POBF) and retrobulbar hemodynamics were measured using a POBF analyzer and transcranial Doppler imaging, respectively. Visual acuity, intraocular pressure, and blood pressure were also evaluated before and after treatment. RESULTS: Twenty-five eyes of 25 patients were included in this study. POBF increased significantly (16.8 ± 4.6 µL/sec vs. 19.6 ± 6.2 µL/sec, p < 0.001) after administration of cilostazol, while no significant change was identified in visual acuity, intraocular pressure, and blood pressure. Mean flow velocity in the ophthalmic artery as measured with transcranial Doppler imaging also increased significantly after medication (23.5 ± 5.6 cm/sec vs. 26.0 ± 6.9 cm/sec, p = 0.001). The change in POBF directly correlated with the change in mean flow velocity (r = 0.419, p = 0.007). CONCLUSIONS: Cilostazol was effective in increasing ocular blood flow in patients with diabetic retinopathy, possibly by modulating retrobulbar circulation.