Measurement of the Optic Nerve Sheath Diameter

Microconvex Probe Versus Linear Probe for Measurement of the Optic Nerve Sheath Diameter

This study is a prospective assessment of the accuracy of ocular ultrasound as a tool to measure the diameter of the optic nerve sheath and the eyeball transverse diameter in healthy adult patients presenting to the Emergency Department and have confirmatory imaging of the optic nerve as part of their clinical care.

This will be a prospective evaluation of accuracy of microconvex and linear transducers for ultrasound measurements of the ONSD and the ETD. Study population will be adult patients that present to Cleveland Clinic Akron General Emergency Department between July 1, 2022 and July 31 April 1, 2023. Patients will be identified on the Emergency Medicine Department tracking board. Patients, once identified as meeting inclusion criteria will be asked to participate in this study and full written consent will be required. All participants will have identical procedures and there will be no groups.

Inclusion criteria:

• 18 years of age and older, and;
• Present to Cleveland Clinic Akron General's ED (Main)
• Have CT head and/or ocular ordered as a part of clinical care that is read as normal or no acute disease (confirmatory imaging), and;
• Agree to and provide written consent for participation.

Exclusion criteria:

• Acute ocular pathology
• Abnormal brain and/or ocular CT
• History of increased intracranial pressure or optic nerve disease
• Not medically stable
• Pregnant or incarcerated
• Unable to consent.