Ultrasonographic measurement of optic nerve sheath diameter as a predictor of severity of preeclampsia: a cross-sectional analytic study

Background An increase in intracranial pressure (ICP) is one of the consequences of preeclampsia. Changes in the optic nerve sheath diameter (ONSD) are an important demonstration of increased ICP. Our study aimed to investigate the value of ultrasound-measured ONSD in detecting brain edema in preeclamptic patients when compared to computed tomography (CT) brain and predicting the severity of preeclampsia. Patients and methods We studied 60 patients with preeclampsia at Kasr Al-Ainy hospitals in Egypt from October 2022 to February 2023. The patients were divided into two equal groups according to the criteria of the severity of preeclampsia: group A: nonsevere (30 patients) and group B: severe (30 patients). Complete medical history, physical examination, and laboratory investigations were obtained. All patients underwent CT brain and ultrasound-measured ONSD. Results ONSD showed a mean of 5.5±0.46 mm in the whole study population and was significantly higher among patients who had brain edema by CT compared to those who showed no brain edema features (6.40±0.45 vs. 4.59±0.47 mm) with sensitivity 84.6% and specificity 97.1%. Patients with severe preeclampsia showed a significantly higher ONSD (6.22±0.66 vs. 4.53±0.39 mm) compared to those with nonsevere sensitivity of 84% and specificity of 97%, with a cutoff value of 5.85 mm. Conclusion Ultrasound-measured ONSD is a feasible, sensitive, and highly specific tool in diagnosing increased ICP among patients with preeclampsia and can be used as a predictive tool of severe preeclampsia.