Changes in Orbital Hemodynamics Induced by Nipradilol in Healthy Volunteers

Abstract

We evaluated changes in ocular hemodynamics induced by nipradilol, an NO donor, applied as an eye drop. Eight volunteers underwent color Doppler imaging for measurement of hemodynamic parameters in the central retinal artery (CRA) and ophthalmic artery (OA) after instillation of nipradilol. Intraocular pressure (IOP) and systemic blood pressure were also measured. Two months later, the same volunteers were examined after instillation of saline into the same eyes to obtain control data. The pulsatility index in the CRA was significantly lowered in the eyes treated with nipradilol compared with control eyes. Blood velocities in the CRA, hemodynamic parameters in the OA, IOP, blood pressure, and ocular perfusion pressure were unaffected by nipradilol. The current study suggests that nipradilol may dilate the CRA as a result of reduced vascular resistance in humans.