Investigating the relationship between ultrasound measured optic nerve sheath diameter and preeclampsia

Background: Increased intracranial pressure (ICP) is one of the main consequences of preeclampsia, which could be manifested by a change in the optic nerve sheath diameter as a radiologic and clinical sign. However, the effect of preeclampsia on the ultrasound measured optic nerve sheath diameter (ONSD) and its possible applications are rarely investigated. The aim of this study was to determine the relationship between ultrasound measured optic nerve sheath diameter and the risk of preeclampsia. Methods: This case-control study was performed on 38 pregnant women with normal blood pressure and 38 pregnant women with preeclampsia in Alzahra hospital in Rasht during 2018. A checklist was used to record demographic and clinical data. Measurements were made using a high resolution transducer, by placing the focal point and a cursor line at 3 mm behind the globe, perpendicular to the optic nerve axis (measuring the mean of two eyes). Data were analyzed by SPSS software version 21. Results: The mean age of patients with preeclampsia and normal pregnant women were 31.42 ± 6.2 years and 29.76 ± 3.46 years, respectively. Differences in gravidity (P = 0.854) and the history of hypertension (P = 0.946) in both groups were not statistically significant (P < 0.05). The mean optic nerve sheath diameter in women with preeclampsia was significantly higher than pregnant women with normal blood pressure (P = 0.001). The area under the ROC curve for the ONSD was 0.82 and the cut-off point for this index was calculated as 4.55 mm, which at this point, sensitivity and specificity were 78.9% and 73.7%, respectively. Conclusion: There was a relationship between the risk of preeclampsia and ONSD, in the way that the ONSD in preeclampsia patients was higher than that of normal subjects. However, the mean ONSD in two groups of mild and severe preeclampsia were not significantly different.