 One eye is randomly selected in 18 healthy subjects. OPA is assessed with Dynamic Contour Tonometry. Submacular choroidal blood flow is measured with Laser Doppler Flowmetry. During both examinations the systemic blood pressure is continuously recorded with Finometer. An average systolic and diastolic LDF parameter flow during 30 seconds are determined and the pulsatility index is calculated according to the formula LDFsys-LDFdiaLDFdia. An association of OPA with the LDF pulsatility index, systemic blood pressure values and mean intraocular pressure will be analysed. 