Blood Flow Imaging for Glaucoma

Recruiting in Palo Alto (17 mi)

Age: 18+

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Academic

Recruiting

Sponsor: University of Maryland, Baltimore

Disqualifiers: Media opacity, Ocular surgery, Diabetes, others

No Placebo Group

Approved in 3 Jurisdictions

Trial Summary

What is the purpose of this trial?

The goal of this clinical trial is to investigate the use of an FDA-cleared retinal blood flow imaging instrument called the XyCAM RI and XyCAM FC (Vasoptic Medical, Inc., Columbia, MD) in glaucoma management. The main question it aims to answer are: * Can the investigators use blood flow to discriminate between eyes with early-stage glaucoma and variable-matched controls? * Can the investigators validate that the XyCAM FC simultaneously captures both stereo fundus photography and ocular blood flow monitoring? Participants will be * measured for their blood pressure, heart rate, height, and weight * dilated with tropicamide * imaged using the XyCAM RI, fundus photography, optical coherence tomography, and standard automated perimetry * imaged using the XyCAM RI while inhaling 100% oxygen through a mask

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It is best to discuss this with the trial coordinators or your doctor.

What data supports the effectiveness of the treatment Oxygen, O2, for glaucoma?

The research suggests that oxygen may play a role in improving blood flow in the eye, which is important for glaucoma patients. One study found that increased oxygen levels can affect blood flow in the optic nerve head, which is crucial for maintaining eye health in glaucoma. ^{1 2 3 4 5}

Is blood flow imaging for glaucoma safe for humans?

The research articles reviewed focus on the techniques and importance of measuring ocular blood flow in glaucoma but do not provide specific safety data for humans regarding blood flow imaging techniques. ^{1 2 6 7 8}

How does the treatment in the Blood Flow Imaging for Glaucoma trial differ from other treatments for glaucoma?

This treatment is unique because it focuses on imaging and assessing ocular blood flow, which is not commonly used in standard glaucoma treatments. It aims to understand the role of blood flow in glaucoma progression, offering a novel approach compared to traditional treatments that primarily target intraocular pressure. ^{1 2 9 10 11}

Research Team

Grace Forbes, MS

Principal Investigator

University of Maryland, Baltimore

Eligibility Criteria

This trial is for adults with binocular vision who can consent, are healthy or need glaucoma assessment, or have moderate to severe glaucoma in one eye. It's not for those with significant eye issues like cataracts, past surgeries (except some), other diseases besides glaucoma, narrow angles, bad reactions to certain drugs, high refractive error (>15 diopters), or women who are pregnant/nursing.

Inclusion Criteria

Able to provide informed consent

I am 18 or older and can see with both eyes.

I am either healthy, advised to get a glaucoma check, or have moderate to severe glaucoma.

Exclusion Criteria

I have a severe vision blockage due to cataract or corneal scar.

I have diabetes.

I have had an eye condition other than glaucoma.

Trial Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Imaging and Testing

Participants undergo imaging using XyCAM RI, XyCAM FC, fundus photography, optical coherence tomography, and standard automated perimetry. Tropicamide is administered for pupil dilation.

Less than 80 minutes for test data sessions, plus 60 minutes for standard clinical data

Follow-up

Participants are monitored for safety and effectiveness after imaging and testing

4 weeks

Treatment Details

Interventions

• Oxygen (Other)

Trial Overview The study tests the XyCAM RI and FC devices' ability to use blood flow imaging for managing glaucoma. Participants will undergo various imaging procedures including fundus photography and ocular blood flow monitoring while breathing pure oxygen through a mask.

Participant Groups

Group I: Pre-perimetric Glaucoma Experimental Treatment 1 Intervention

All participants with pre-perimetric glaucoma will be first be imaged pre-intervention.

Group II: Glaucoma Experimental Treatment 1 Intervention

All participants with glaucoma will be first be imaged pre-intervention.

Group III: Control Experimental Treatment 1 Intervention

All control participants will be first be imaged pre-intervention.

Who Is Running the Clinical Trial?

University of Maryland, Baltimore

Lead Sponsor

Trials

729

Recruited

540,000+

Dr. Mohan Suntha

University of Maryland, Baltimore

Chief Executive Officer since 2019

MD from Jefferson Medical College, MBA from Wharton School of Business, BA from Brown University

Dr. Taofeek K. Owonikoko

University of Maryland, Baltimore

Chief Medical Officer

MD, PhD

National Eye Institute (NEI)

Collaborator

Trials

572

Recruited

1,320,000+

Dr. Michael F. Chiang

National Eye Institute (NEI)

Chief Executive Officer since 2020

MD from Harvard Medical School

Dr. Richard Lee

National Eye Institute (NEI)

Chief Medical Officer since 2021

MD, PhD from Harvard Medical School

Vasoptic Medical, Inc

Collaborator

Trials

1

Recruited

150+

Findings from Research

This review highlights the importance of ocular blood flow (OBF) in understanding glaucoma, a disease influenced by intraocular pressure and reduced blood flow, emphasizing the need for updated imaging technologies.

Recent advancements in imaging techniques for measuring OBF are crucial for both diagnosing and monitoring the progression of glaucoma, as they provide valuable insights into the disease's multifactorial nature.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Current State of Knowledge in Ocular Blood Flow in Glaucoma: A Narrative Review. Alasbali, T.[2023]

This review discusses various advanced imaging techniques used to study ocular blood flow, which is important for understanding vascular dysfunction related to diseases like glaucoma.

By highlighting the strengths and limitations of these imaging methods, the review aims to help physicians better interpret research findings and their implications for ocular health and disease management.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Measuring and interpreting ocular blood flow and metabolism in glaucoma. Harris, A., Kagemann, L., Ehrlich, R., et al.[2016]

In a study involving 15 primary open-angle glaucoma (POAG) patients and 15 age-matched controls, POAG patients showed a significantly weaker optic nerve head blood flow response to hyperoxia compared to controls, indicating impaired vasoreactivity (P < 0.0001).

The reduced response in POAG patients was linked to lower baseline blood flow and higher systolic blood pressure, suggesting that pre-existing vasoconstriction may limit their ability to respond to increased oxygen levels.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Effect of Systemic Hyperoxia on Optic Nerve Head Blood Flow in Primary Open-Angle Glaucoma Patients. Kiyota, N., Shiga, Y., Suzuki, S., et al.[2019]

In a study of 14 glaucomatous subjects, visual field loss was linked to reduced retinal blood flow and oxygen delivery, indicating that these factors may contribute to the progression of glaucoma.

The research found that as visual field loss increased, there was a corresponding rise in the retinal oxygen extraction fraction, suggesting that the retina is struggling to obtain enough oxygen under these conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Relating glaucomatous visual field loss to retinal oxygen delivery and metabolism. Aref, AA., Maleki, S., Tan, O., et al.[2020]

The new phosphorescence imaging technique effectively measured oxygen tension in the optic nerve head and retina of cats, showing that oxygen levels were well maintained even with moderate increases in intraocular pressure (IOP).

The study suggests that acute increases in IOP do not lead to hypoxia in the optic nerve head, indicating that lack of oxygen may not be a primary factor in glaucomatous damage, although further research is needed on the effects of chronic IOP elevation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of acute increases in intraocular pressure on intravascular optic nerve head oxygen tension in cats. Shonat, RD., Wilson, DF., Riva, CE., et al.[2013]

Open-angle glaucoma (OAG) is influenced by both intraocular pressure (IOP) and other risk factors, particularly decreased ocular blood flow (OBF), which may play a crucial role in the disease's progression, especially in normal-tension glaucoma, the most common type in Asia.

Recent advancements in noninvasive imaging techniques, like laser speckle flowgraphy and optical coherence tomography angiography, allow for precise monitoring of OBF changes, which correlate with the severity of glaucomatous damage, potentially aiding in early detection and management of the disease.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Ocular Blood Flow and Influencing Factors for Glaucoma. Nakazawa, T.[2022]

In a study involving 14 healthy subjects, isoxic hypercapnia (breathing CO2) significantly increased blood flow and velocity in the short posterior ciliary arteries and the superior temporal quadrant of the retina, indicating enhanced ocular blood flow during this condition.

The results suggest that the ocular vasculature has autoregulatory mechanisms that respond to increased CO2 levels, which could be important for understanding conditions like glaucoma where these mechanisms may be impaired.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comprehensive assessment of retinal, choroidal and retrobulbar haemodynamics during blood gas perturbation. Roff, EJ., Harris, A., Chung, HS., et al.[2019]

In a study of 15 glaucoma patients with asymmetric scotomas, the more affected eyes showed significantly lower pulsatile ocular blood flow compared to the contralateral eyes, suggesting that blood flow may play a role in the severity of glaucoma.

Despite equal intraocular pressure (IOP) between the eyes, differences in optic nerve head excavation and mean deviation in scotomas were significant, indicating that hemodynamic factors could contribute to the pathogenesis of glaucoma.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Ocular blood flow in patients with asymmetric glaucoma]. Kuba, GB., Austermann, P., Kroll, P.[2007]

In patients with primary open angle glaucoma (POAG), ocular blood flow is significantly compromised, as indicated by lower peak systolic and end diastolic velocities, and higher resistance index compared to control eyes.

Those with progressive visual field loss show even greater impairment in ocular blood flow, particularly in the ophthalmic and medial posterior ciliary arteries, suggesting a potential link between blood flow and visual field deterioration.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Doppler evaluation of ocular vessels in patients with primary open angle glaucoma. Suprasanna, K., Shetty, CM., Charudutt, S., et al.[2019]

Glaucoma is influenced by various factors including elevated intraocular pressure and blood flow, and understanding ocular hemodynamics could improve detection and treatment options.

Current methods for measuring ocular blood flow have limitations, but new imaging technologies are being developed to better assess ocular perfusion pressure in glaucoma patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Current Imaging Modalities for assessing Ocular Blood Flow in Glaucoma. Mohindroo, C., Ichhpujani, P., Kumar, S.[2022]

In this study of 130 eyes (95 normal and 35 with primary open angle glaucoma), it was found that normal subjects had a mean pulsatile ocular blood flow (POBF) of 1382.2 ml/min, while glaucoma patients with high intraocular pressure (IOP) had significantly reduced POBF at 718.9 ml/min.

After controlling IOP to below 22 mmHg, the POBF in glaucoma patients improved to 1129 ml/min, indicating that lowering IOP positively affects ocular blood flow and may benefit patients with glaucoma.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Pulsatile ocular blood flow among normal subjects and patients with high tension glaucoma. Agarwal, HC., Gupta, V., Sihota, R., et al.[2008]

References

1. New Zealand pubmed.ncbi.nlm.nih.gov

Current State of Knowledge in Ocular Blood Flow in Glaucoma: A Narrative Review. [2023]

2. England pubmed.ncbi.nlm.nih.gov

Measuring and interpreting ocular blood flow and metabolism in glaucoma. [2016]

3. United States pubmed.ncbi.nlm.nih.gov

The Effect of Systemic Hyperoxia on Optic Nerve Head Blood Flow in Primary Open-Angle Glaucoma Patients. [2019]

4. England pubmed.ncbi.nlm.nih.gov

Relating glaucomatous visual field loss to retinal oxygen delivery and metabolism. [2020]

5. United States pubmed.ncbi.nlm.nih.gov

Effect of acute increases in intraocular pressure on intravascular optic nerve head oxygen tension in cats. [2013]

6. China pubmed.ncbi.nlm.nih.gov

Ocular Blood Flow and Influencing Factors for Glaucoma. [2022]

7. Germany pubmed.ncbi.nlm.nih.gov

Comprehensive assessment of retinal, choroidal and retrobulbar haemodynamics during blood gas perturbation. [2019]

8. Germany pubmed.ncbi.nlm.nih.gov

[Ocular blood flow in patients with asymmetric glaucoma]. [2007]

9. United States pubmed.ncbi.nlm.nih.gov

Doppler evaluation of ocular vessels in patients with primary open angle glaucoma. [2019]

10. India pubmed.ncbi.nlm.nih.gov

Current Imaging Modalities for assessing Ocular Blood Flow in Glaucoma. [2022]

11. India pubmed.ncbi.nlm.nih.gov

Pulsatile ocular blood flow among normal subjects and patients with high tension glaucoma. [2008]