Study Status: Completed
Recruit Status: Unknown status
Study Type: Interventional
Official Title: Non-invasive Absolute Intracranial Pressure (ICP) Measurement in Patients With Open-angle Glaucoma and Papilledema
Brief Summary:
Glaucoma remains a disease with an unclear and complex underlying pathophysiology. Recently, researchers have emphasized not only intraocular pressure (IOP) or vascular dysregulation, but also translaminar pressure's (TPG) role in glaucoma (TPG=IOP-ICP). A higher TPG may lead to abnormal function and optic nerve damage due to changes in axonal transportation, deformation of the lamina cribrosa, altered blood flow, or a combination thereof leading to glaucomatous damage. However only invasive ICP measurements are available within the contemporary medicine. The ideas for non-invasive ICP measurement have been approached since about 1980. Most of the proposed technologies were based on ultrasound and were capable of monitoring blood flow in intracranial or intraocular vessels, cranium diameter, or acoustic properties of the cranium. Broad research has extended into sonography of optic nerve sheath and its relation with elevated ICP. However, most of these correlation-based methods had the same problem—the need of individual patient specific calibration. Seeking to measure absolute ICP values, researchers from Kaunas University of Technology created a non-invasive method, which does not need a patient specific calibration. The method is based on direct comparison of ICP value with the value of pressure Pe that is externally applied to the tissues surrounding the eyeball. Intracranial segment of ophthalmic artery (OA) is used as a natural sensor of ICP and extracranial segment of OA is used as a sensor of Pe. The special two depth transcranial Doppler (TCD) device is used as a pressure balance indicator when ICP = Pe.
The aim of our study is to assess TPG in patients with primary open open-angle glaucoma (POAG). In addition the investigators want to measure ICP in patients with papilledema (PE) in order to compare them with glaucoma patients.