NCT05344274 · University of Maryland, Baltimore
Retinal Blood Flow and Autoregulation
What this study is about
The purpose of this study is to establish autoregulation of retinal blood flow in arterioles and capillaries as a biomarker for early primary open angle glaucoma.
View original scientific description
The purpose of this study is to establish autoregulation of retinal blood flow in arterioles and capillaries as a biomarker for early primary open angle glaucoma.
Interventions
DIAGNOSTIC_TEST
Indocyanine Green Angiography
Erythrocyte Mediated Angiography with indocyanine green as well as conventional indocyanine green angiography will be conducted to determine retinal blood flow
BIOLOGICAL
Isocapnic Oxygen
Investigators will evaluate retinal blood flow (RBF) in response to oxygen supplementation at a constant level of carbon dioxide (isocapnic hyperoxia) to isolate the vascular autoregulatory response to oxygen.
DIAGNOSTIC_TEST
Ocular Imaging with Optical Coherence Tomography (OCT) and Adaptive Optics (AO)
Investigators will image subjects with OCT as well as AO technology to determine retinal ganglion cell density, vessel density, and vessel flowrates
Primary outcome measures
Autoregulation of retinal blood flow
Time frame: 3 years
Autoregulation of flow is measured by the percent flow difference in flow between air and oxygen
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- age over 18 years 2. open angle in gonioscopy (grade 3 or 4 in Shaffer classification) 3. refractive error within the range of +3.00 to -8.00 diopters (4) best-corrected visual acuity 20/25 or better (5) Individuals recruited will be in one of the 3 groups: 1\) Early Glaucoma as per Hodapp-Anderson-Parrish Criteria (54). Early glaucoma subjects specifically with visual field defects restricted to one side of the horizontal midline will be selected to allow for comparison of rates of progression in both hemifields. Individuals will need to be off of glaucoma medications for four weeks to participate in the study. 2) Pre-perimetric glaucoma defined as the presence of glaucomatous optic nerve damage (e.g., focal notching, rim thinning), RNFL defect, and the absence of a definite glaucomatous visual field defect using standard automated perimetry at the three most recent consecutive examinations. A glaucomatous visual field defect is defined as either 3 or more abn
Where
- Baltimore, Maryland
- Silver Spring, Maryland
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Dec 2, 2025 · Source of record for eligibility and locations