Ophthalmic artery Doppler for prediction of pre‐eclampsia: systematic review and meta‐analysis

Objective To determine the accuracy of ophthalmic artery Doppler in pregnancy for the prediction of pre‐eclampsia (PE). Methods MEDLINE, EMBASE, CINAHL and The Cochrane Library were searched for relevant citations without language restrictions. Two reviewers independently selected studies that evaluated the accuracy of ophthalmic artery Doppler to predict the development of PE and extracted data to construct 2 × 2 tables. Individual patient data were obtained from the authors if available. A bivariate random‐effects model was used for the quantitative synthesis of data. Logistic regression analysis was employed to generate receiver–operating characteristics (ROC) curves and obtain optimal cut‐offs for each investigated parameter, and a bivariate analysis was employed using predetermined cut‐offs to obtain sensitivity and specificity values and generate summary ROC curves. Results A total of 87 citations matched the search criteria of which three studies, involving 1119 pregnancies, were included in the analysis. All included studies had clear description of the index and reference tests, avoidance of verification bias and adequate follow‐up. Individual patient data were obtained for all three included studies. First diastolic peak velocity of ophthalmic artery Doppler at a cut‐off of 23.3 cm/s showed modest sensitivity (61.0%; 95% CI, 44.2–76.1%) and specificity (73.2%; 95% CI, 66.9–78.7%) for the prediction of early‐onset PE (area under the ROC curve (AUC), 0.68; 95% CI, 0.61–0.76). The first diastolic peak velocity had a much lower sensitivity (39.0%; 95% CI, 20.6–61.0%), a similar specificity (73.2%; 95% CI, 66.9–78.7%) and a lower AUC (0.58; CI, 0.52–0.65) for the prediction of late‐onset PE. The pulsatility index of the ophthalmic artery did not show a clinically useful sensitivity or specificity at any cut‐off for early‐ or late‐onset PE. Peak ratio above 0.65 showed a similar diagnostic accuracy to that of the first diastolic peak velocity with an AUC of 0.67 (95% CI, 0.58–0.77) for early‐onset PE and 0.57 (95% CI, 0.51–0.63) for late‐onset disease. Conclusions Ophthalmic artery Doppler is a simple, accurate and objective technique with a standalone predictive value for the development of early‐onset PE equivalent to that of uterine artery Doppler evaluation. The relationship between ophthalmic Doppler indices and PE cannot be a consequence of trophoblast invasion and may be related to maternal hemodynamic adaptation to pregnancy. The findings of this review justify efforts to elucidate the effectiveness and underlying mechanism whereby two seemingly unrelated maternal vessels can be used for the prediction of a disease considered a ‘placental disorder’.