Ocular pulse amplitude during manipulation of systemic perfusion parameters

The mechanism for the control of choroidal perfusion is unclear. The present study was designed to investigate for the effect of standardized alteration of systemic perfusion parameters on choroidal hemodynamics in healthy volunteers. Intraocular pressure (IOP; German abbreviation: IOD), Ocular Pulse Amplitude (OPA), systemic blood pressure, and pulse rate were measured, and ocular perfusion pressure was calculated in 14 otherwise non-smoking, healthy volunteers prior to and following exercise and smoking. Exercise significantly (sig., p < 0.05) increased pulse rate, systolic blood pressure and ocular perfusion pressure, while it sig. (p < 0.05) reduced IOP and diastolic blood pressure. However OPA was not sig. (p > 0.1) affected by changes in these parameters. Smoking sig. (p < 0.05) increased systolic blood pressure, diastolic blood pressure, pulse rate, and ocular perfusion pressure but did not sig. (p > 0.09) alter OPA. Despite affecting ocular and systemic perfusion parameters, exercise and smoking did not alter OPA, suggesting functional isolation i.e. autoregulation of the choroidal and/or ophthalmic artery circulation.