Optic Nerve Sheath Diameter on Transorbital Ultrasound as a Noninvasive Marker of Raised Intracranial Pressure in Preeclampsia and Eclampsia Compared With Normotensive Pregnancy: A Systematic Review and Meta‐Analysis

ABSTRACT

Preeclampsia and eclampsia remain leading contributors to maternal morbidity and mortality worldwide, and cerebral complications driven by raised intracranial pressure are among their most feared, yet hardest to detect, sequelae. Transorbital ultrasound measurement of optic nerve sheath diameter is a noninvasive bedside surrogate for raised intracranial pressure, but pooled differences between preeclamptic/eclamptic and normotensive pregnancies have not been synthesised. We systematically searched PubMed, Scopus, Web of Sciences and Embase from inception to May 2026 for studies measuring optic nerve sheath diameter by transorbital ultrasound in women with preeclampsia or eclampsia compared with normotensive pregnant women. Screening followed PRISMA 2020; risk of bias and evidence certainty were assessed using an adapted Newcastle–Ottawa Scale and GRADE, respectively. Seventeen studies met inclusion criteria; 12, comprising 11 independent comparisons, contributed evaluable mean and standard deviation data. Optic nerve sheath diameter was significantly larger in preeclampsia/eclampsia than in normotensive pregnancy (mean difference 0.89 mm, 95% confidence interval 0.47–1.31, I ² 97.2%, p  < 0.0001). The mean difference was similar for mild/nonsevere and severe preeclampsia (1.20 vs. 1.18 mm) but smaller for the single‐study eclampsia subgroup (0.40 mm), indicating no progressive severity gradient. No small‐study or publication bias was detected. Certainty of evidence was low due to substantial unexplained heterogeneity. Transorbital ultrasound optic nerve sheath diameter is consistently and meaningfully larger in preeclampsia and eclampsia than in normotensive pregnancy, supporting its candidacy as a noninvasive adjunct for bedside risk stratification relevant to maternal health and well‐being.