[Ocular Blood Flow Regulation in XXXX - Examination with the Ocular Pressure Flow Analyzer (OPFA)].

@entity1 @entity725 @entity2790 @entity726
BACKGROUND: The results of studies of ocular blood flow (BF) regulation of @entity1 with @entity725 ( @entity725 ), normal-tension @entity726 (NTG) and @entity2790 ( @entity2790 ) are presented. METHODS AND @entity1 : Examinations were carried out with the "OPFA", a newly developed ocular pressure flow analyzer (producer: tpm L  neburg) on 92 @entity1 with newly diagnosed @entity726 , among whom 48 @entity1 had @entity725 , 22 NTG and 22 @entity2790 , and compared with age-matched groups of healthy subjects. The OPFA uses pneumatic coupling through special scleral suction cups to record ocular pulses with highly sensitive transducers and a suction pump for simultaneously increasing intraocular pressure (IOP). Following local drop anaesthesia on both eyes, IOP is artificially raised to suprasystolic values. While continuously lowering IOP, the ocular pulse is then recorded with increasing ocular perfusion pressure. We obtain the relative ocular pulse blood volume by correlating the ocular pulse amplitudes with a calibration volume of 1     l. This enables us to collect reproducible data on intra- and inter-individual pulse blood volume (PVoc). The ocular perfusion pressure pulse blood volume curve characterizes the respective individual ocular circulation as well as systolic and diastolic ocular perfusion pressures. RESULTS: In healthy subjects, the ocular pulse blood volume remains stable over a certain range of ocular perfusion pressure (ppoc) changes. After exceeding a critical point (CP), the ocular pulse blood volume drops. We refer to the difference between the CP and IOP as the autoregulatory capacity (AC). In @entity1 with @entity725 and in @entity1 with NTG, the AC was reduced significantly compared with the groups of healthy subjects. The mean AC of @entity1 with @entity2790 remained within the normal range. The ROC curves showed at an optimal cut-off value for @entity725 a sensitivity of 75.0% and a specificity of 97.9%, for NTG a sensitivity of 77.3% and a specificity of 100%. In @entity1 with @entity725 and @entity2790 , the ocular arterial pressures were elevated. In @entity1 with NTG they remained unchanged compared with the healthy subjects. The ocular perfusion pressures did not change in @entity725 as well as in NTG and @entity2790 . CONCLUSIONS: In @entity1 with @entity725 and in @entity1 with NTG the ocular BF regulation was impaired and detected by the OPFA device with a high level of reliability. Ocular arterial blood pressures were increased as a result of vascular regulation to keep up the ocular perfusion pressure and to maintain ocular perfusion.
