Simultaneous measurement of ocular micro- and macrocirculation, intraocular pressure, and systemic functions.

SIMOMIMA (simultaneous measurement of ocular micro- and macrocirculation) is a 32-channel system for display and analysis of biophysical data on ocular perfusion. Using SIMOMIMA in the real-time mode, several parameters of ocular perfusion and systemic functions were simultaneously measured noninvasively and stored during varying periods of measurement; including ocular macroperfusion (pulsed Doppler sonography: ophthalmic artery), ocular microperfusion (laser Doppler flowmetry; iris, ciliary body, choroid), intraocular pressure, cardiac pulse, respiration, and arterial blood pressure. All data were digitalized and stored by a microcomputer for further data processing. With SIMOMIMA in the off-line mode, several parameters of the ocular and systemic circulation may be examined and correlations between them may be calculated, including absolute values for the ophthalmic-artery blood velocity expressed in centimeters per second; the pulse-wave velocity expressed in centimeters per second; relative values for the microcirculatory blood flow of the iris, ciliary body, or choroid; and absolute values for and the time course of the intraocular pressure, heart rate, and respiration rate. In contrast to the ophthalmic-artery pulse curve, the microcirculatory blood flow in the iris showed no obvious synchronization with the ECG or the respiration rate. The blood-cell velocity and the blood content in the iridal meshwork fluctuated with frequencies ranging between 0.5 and 4 Hz. By a special statistical procedure called averaging laser Doppler flowmetry (ALDF), the influence of the pulsations of the arterial blood pressure (diastolic systolic blood pressure) on the iridial blood flow becomes visible.(ABSTRACT TRUNCATED AT 250 WORDS)