Transorbital Ultrasound of Optic Nerve Sheath Diameter Between Healthy Pregnant Women and Those With Severe Preeclampsia.

Not Applicable

Completed

• Conditions: Preeclampsia Severe
• Interventions: Procedure: Transorbital ultrasound of the optic nerve sheet

• Registration Number: NCT05594056
• Lead Sponsor: Saint Thomas Hospital, Panama

Brief Summary

The neurological alterations associated with preeclampsia depend on cerebral autoregulation, a theory that outlines the mechanisms by which the nervous system controls cerebral perfusion. However, with the loss of autoregulation, increased blood flow, edema and eventually increased intracranial pressure are triggered and may be translated into neurological manifestations such as symptoms of vasospasm, one of the criteria for severity in preeclampsia.

Nervous system manifestations frequently found in preeclampsia are headache, blurred vision, scotomas and hyperreflexia. Although uncommon, temporary blindness (lasting a few hours to a week) may also accompany severe preeclampsia and eclampsia.

The optic nerve, as part of the central nervous system, is surrounded by cerebrospinal fluid and dura mater, which forms the optic nerve sheath. Due to the connection with the intracranial subarachnoid space, the diameter of the optic nerve sheath is influenced by variations in cerebrospinal fluid pressure. Increased intracranial pressure is transmitted to the subarachnoid space surrounding the optic nerve, causing its expansion.

Recent studies suggest that an optic nerve sheath diameter greater than 5 mm correlates 100% with ICP (intracerebral pressure) greater than 20 mm Hg. Due to the simple nature of the test and the limited time required to perform it, it is an ideal non-invasive test to assess changes in mental status, severe headache, and to take the necessary measures aimed at reducing intracranial pressure.

The diagnosis of elevated intracranial pressure is challenging and critical, because early recognition and treatment are essential to prevent brain damage or death since preeclampsia with severe data remains one of the most frequent complications in our institution.

These values are not taken from the obstetric population, so this study proposes the description of a standard value for the pregnant population. There are few studies that describe a value to help us define cases of this pathology and correlate it with the signs and symptoms of severity in patients with preeclampsia.

Detailed Description

Not available

Study Timeline

• Study Start: 2022-10-21
• Study First Submitted: 2022-10-21
• Study First Submitted QC: 2022-10-21
• Study First Posted: 2022-10-26
• Primary Completion: 2022-12-31
• Study Completion: 2023-01-31
• Status Verified: 2023-04
• Last Update Submitted: 2023-04-25
• Last Update Posted: 2023-04-27

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 100

Inclusion Criteria

• Age between 15-44 years.
• Gestational age between 34-40 weeks of gestation.

Exclusion Criteria

• Eye disease (Glaucoma, diabetic neuropathy, optic neuritis).
• Nervous disorders.
• Psychiatric disorders
• Diabetes

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Preeclampsia	Transorbital ultrasound of the optic nerve sheet	Patients with severe preeclampsia and gestational age between 34-40 weeks.
Control	Transorbital ultrasound of the optic nerve sheet	Patients with normal gestations between 34-40 weeks.

Primary Outcome Measures

Name	Time	Method
Optic nerve sheet measurement	24 hours	The diameter of the optic nerve sheath was measured three millimeters behind the eyeball, and one axis perpendicular to the optic nerve. Three measurements were taken in each eye. The resulting six measurements were averaged to give a mean of the optic nerve sheet measurement, to minimize measurement variability.

Trial Locations

Locations (1)

Saint Thomas H; 🇵🇦 Panama, Panama