Understanding retinal blood flow in glaucoma patients
Direct Measures of Retinal Blood Flow and Autoregulation as Robust Biomarkers for Early Glaucoma
This study is testing if measuring blood flow in the retina can help find early signs of glaucoma in patients so that better treatments can be developed.
Quick facts
| Phase | Phase 4 |
|---|---|
| Study type | Interventional |
| Enrollment | 90 (estimated) |
| Ages | 18 Years to 88 Years |
| Sex | All |
| Sponsor | University of Maryland, Baltimore Academic / other |
| Locations | 4 sites (Baltimore, Maryland and 3 other locations) |
| Trial ID | NCT05344274 on ClinicalTrials.gov |
What this trial studies
This study aims to establish retinal blood flow autoregulation as a biomarker for early primary open angle glaucoma (POAG). It focuses on the relationship between impaired retinal blood flow and the progression of glaucoma, utilizing advanced imaging techniques such as erythrocyte mediated angiography flowmetry and multimodal adaptive optics. By directly measuring retinal blood flow, the researchers hope to identify early signs of glaucoma that could lead to more effective interventions. The study will assess the extent of autoregulatory impairment and its predictive value for glaucoma damage.
Who should consider this trial
Good fit: Ideal candidates include adults over 18 with early or pre-perimetric glaucoma and specific visual field criteria.
Not a fit: Patients with advanced glaucoma or those currently on glaucoma medications may not benefit from this study.
Why it matters
Potential benefit: If successful, this study could lead to earlier detection and potentially reversible treatment options for patients with glaucoma.
How similar studies have performed: Previous studies have indicated a vascular component in glaucoma, but this approach using direct measures of retinal blood flow is relatively novel.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: 1. 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 abnormal points with a P\<0.05, of which at least 1 point has a pattern standard deviation (PSD) of P\<0.01; or a PSD of P\<0.05; or glaucoma hemifield test values outside the normal limits. (55,56) 3) Control group - A subject with no family history of glaucoma who has the following: a) OCT with all four quadrants within the normal range for age-matched controls, b) reliable visual fields with glaucoma hemifield test within normal limits and determined to be normal by a glaucoma specialist, and c) cup-to-disc ratio of 0.4 or lower and asymmetry of the cup to disc ratio no greater than 0.1 as determined by a glaucoma specialist. Control subjects will be age matched to the early glaucoma subjects. Exclusion Criteria: 1. corneal abnormalities or other conditions preventing reliable applanation tonometry 2. retinal disease affecting retinal nerve fiber layer thickness such as vitreomacular traction as determined by a glaucoma specialist 3. secondary glaucoma 4. history of prior ocular surgery other than uncomplicated cataract surgery or laser trabeculoplasty 5. inability to safely be off of glaucoma medications for 4 weeks 6. inability to obtain OCT angiography data due to excessive eye motion or inability to fixate 7. unreliable visual fields 8. any history of smoking in the past 6 months 9. cataract greater than lens opacity classification system (LOCS) II Grade≥2 10. diagnosis of diabetes, hypertension, or other known vascular disorder such as vasculitis
Where this trial is running
Baltimore, Maryland and 3 other locations
- University of Maryland Faculty Physicians, Inc — Baltimore, Maryland, United States (Recruiting)
- University of Maryland Medical Center — Baltimore, Maryland, United States (Recruiting)
- University of Maryland, Baltimore — Baltimore, Maryland, United States (Recruiting)
- Food and Drug Administration (FDA) — Silver Spring, Maryland, United States (Recruiting)
Study contacts
- Study coordinator: Osamah Saeedi, MD, MS
- Email: osaeedi@som.umaryland.edu
- Phone: (410) 328-5929
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.