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Ophthalmic artery Doppler in prediction of pre‐eclampsia: insights from hemodynamic considerations

We followed with great interest the studies of Sapantzoglou1, Sarno2 and colleagues from the Fetal Medicine Foundation (FMF) group who introduced ophthalmic artery (OA) Doppler as a new tool in their multivariate prediction models for pre-eclampsia (PE) and gestational hypertension, published recently in this Journal. The authors provide valuable and novel preclinical hemodynamic data regarding the relative changes of the first (P1) and second (P2) peak systolic velocities and the predictive capacity of the systolic waveform peak ratio (PR = P2/P1) as a compound index. In this context, the authors classified P2 as a ‘marker of perfusion’. However, no further hemodynamic considerations were stated. We would like to comment on these particular results and their hemodynamic interpretation. The findings of these studies probably represent the first time in obstetrics that Doppler assessment of a combination of two systolic waveform parameters has been found to be decisive, and not a combination of systolic and diastolic values, as is the case for Doppler indices for downstream resistance of uterine or umbilical artery blood flow. While a second systolic peak (P2) is basically unknown in uterine or umbilical artery waveforms, it is present in virtually all cerebral arteries3–5, and is the result of systemic pulsed-wave (PW) reflection and transmission to the cerebral circulation. Thus, hemodynamic considerations may provide an approach to interpret these particular systolic waveform features.