External Influences Upon Ocular Homeostasis

Not Applicable

• Conditions: Intraocular Pressure
• Interventions: Behavioral: Postural change; Behavioral: Water drinking

• Registration Number: NCT00338065
• Lead Sponsor: Vanderbilt University Medical Center

Brief Summary

Our experiments are designed to test the overall hypothesis that position-dependent or water-dependent intra-ocular pressure (IOP) spikes occur in humans, and that these challenge ocular homeostasis.

Detailed Description

Glaucoma is the second leading cause of blindness in the United States, yet its pathogenesis is poorly understood. This is an insidious disorder since the loss of peripheral vision which occurs first usually is not noticed by the victim. Approximately 1 million people in the United States have glaucoma, but are not aware of it. Glaucoma is not always associated with elevated intraocular pressures so that vision screenings which measure just intraocular pressure without assessing the optic nerve will also miss these patients with glaucomatous damage. Therefore, patients are often diagnosed only when they have severe irreversible vision loss. Vascular insufficiency or abnormal autoregulation versus mechanical pressure damage has been proposed as a major factor in the development of glaucoma. Presently, therapy is based upon lowering intraocular pressure. If a contributing intermittent pressure elevation factor can be elucidated and characterized, specific treatment modalities may then be developed and their effectiveness can be monitored.

Study Timeline

• Study Start: 2006-06
• Study First Submitted: 2006-06-15
• Study First Submitted QC: 2006-06-15
• Study First Posted: 2006-06-20
• Status Verified: 2024-12
• Last Update Submitted: 2024-12-11
• Last Update Posted: 2024-12-13
• Primary Completion: 2027-12
• Study Completion: 2027-12

Recruitment & Eligibility

• Status: ENROLLING_BY_INVITATION
• Sex: All
• Target Recruitment: 200

Inclusion Criteria

• Patients with autonomic dysfunction
• Patients with open-angle glaucoma
• Patients with normal-pressure glaucoma
• Normal subjects

Exclusion criteria:

• Medical students
• Prisoners
• Pregnant women

Read More

Exclusion Criteria

Not provided

Read More

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Subjects with normal-pressure glaucoma	Postural change	Subjects with open-angle glaucoma damage following a glaucoma specialist's examination without ever an intraocular pressure recording greater than 21 mm Hg. .1. Intraocular pressures, blood pressures, and retinal thicknesses are measured with postural changes 2. Intraocular pressures, blood pressures, and retinal thicknesses are measured with water drinking.
Subjects with autonomic dysfunction	Postural change	Subjects with known autonomic dysfunction diagnoses as defined by the General Clinical Research Center (GCRC) such as pure autonomic failure, Postural orthostatic tachycardia syndrome (POTS), and Multiple System Atrophy( MSA). 1. Intraocular pressures, blood pressures, and retinal thicknesses are measured with postural changes 2. Intraocular pressures, blood pressures, and retinal thicknesses are measured with water drinking.
Primary open-angle glaucoma subjects	Postural change	Subjects diagnosed with primary open-angle glaucoma following a glaucoma specialist's examination. 1. Intraocular pressures, blood pressures, and retinal thicknesses are measured with postural changes 2. Intraocular pressures, blood pressures, and retinal thicknesses are measured with water drinking.
Subjects with autonomic dysfunction	Water drinking	Subjects with known autonomic dysfunction diagnoses as defined by the General Clinical Research Center (GCRC) such as pure autonomic failure, Postural orthostatic tachycardia syndrome (POTS), and Multiple System Atrophy( MSA). 1. Intraocular pressures, blood pressures, and retinal thicknesses are measured with postural changes 2. Intraocular pressures, blood pressures, and retinal thicknesses are measured with water drinking.
Primary open-angle glaucoma subjects	Water drinking	Subjects diagnosed with primary open-angle glaucoma following a glaucoma specialist's examination. 1. Intraocular pressures, blood pressures, and retinal thicknesses are measured with postural changes 2. Intraocular pressures, blood pressures, and retinal thicknesses are measured with water drinking.
Subjects with normal-pressure glaucoma	Water drinking	Subjects with open-angle glaucoma damage following a glaucoma specialist's examination without ever an intraocular pressure recording greater than 21 mm Hg. .1. Intraocular pressures, blood pressures, and retinal thicknesses are measured with postural changes 2. Intraocular pressures, blood pressures, and retinal thicknesses are measured with water drinking.
Normal subjects	Postural change	Subjects without evidence of glaucoma or autonomic dysfunction. ..1. Intraocular pressures, blood pressures, and retinal thicknesses are measured with postural changes 2. Intraocular pressures, blood pressures, and retinal thicknesses are measured with water drinking.
Normal subjects	Water drinking	Subjects without evidence of glaucoma or autonomic dysfunction. ..1. Intraocular pressures, blood pressures, and retinal thicknesses are measured with postural changes 2. Intraocular pressures, blood pressures, and retinal thicknesses are measured with water drinking.

Primary Outcome Measures

Name	Time	Method
Change in Intraocular Pressure	Within 1 day	A change in intraocular pressure is measured after change in posture or drinking water.

Trial Locations

Locations (1)

Vanderbilt University; 🇺🇸 Nashville, Tennessee, United States