Blood Flow Imaging for Glaucoma

Overseen By Osamah J Saeedi, MD, MS

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Maryland, Baltimore

Disqualifiers: Media opacity, Ocular surgery, Diabetes, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 3 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

150 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores a new method for managing glaucoma using a special imaging device to examine blood flow in the eyes. Researchers aim to determine if this can help identify early-stage glaucoma and improve eye health monitoring. Participants will breathe pure oxygen (O2) during imaging, which might highlight differences in eye conditions. Ideal candidates include those diagnosed with moderate to severe glaucoma or those recommended for a glaucoma check-up, and they must have good vision in both eyes. As an unphased study, this trial offers participants the chance to contribute to groundbreaking research that could enhance glaucoma detection and monitoring.

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 prior data suggests that the XyCAM RI and XyCAM FC are safe for glaucoma management?

Research has shown that oxygen therapy, commonly used in medical settings, is usually safe and well-tolerated. In past studies, patients experienced good safety results with oxygen treatment. For instance, research on hyperbaric oxygen therapy, where patients breathe pure oxygen in a pressurized room, indicated it is safe for eye conditions. Patients did not report major side effects, and any changes in eye pressure were minor and not concerning. Although this study uses oxygen differently, these findings offer some reassurance about its safety. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it explores a potentially groundbreaking method for diagnosing glaucoma through blood flow imaging. Unlike traditional diagnostic methods that focus on optic nerve damage or vision field tests, this approach aims to detect changes in blood flow at an earlier stage. By using oxygen as part of the imaging process, scientists hope to gain a more detailed understanding of how blood flow impacts glaucoma development. This could lead to earlier detection and ultimately better outcomes for patients, which is why there's significant interest in this research.

What evidence suggests that the XyCAM RI and XyCAM FC are effective for glaucoma management?

Research suggests that oxygen therapy might affect glaucoma by altering eye pressure and blood flow. Some studies have shown a small drop in intraocular pressure with oxygen use, though this change might not persist. Lower blood vessel density in the retina can affect oxygen levels, potentially influencing glaucoma progression. However, research has also shown no significant difference in retinal oxygen levels between healthy individuals and those with glaucoma. This trial will include participants with pre-perimetric glaucoma, glaucoma, and control participants to explore these aspects further. The potential benefits of oxygen therapy for glaucoma remain unclear, but it might help manage certain aspects like blood flow. ^{1 2 4 6 7}

Who Is on the Research Team?

Grace Forbes, MS

Principal Investigator

University of Maryland, Baltimore

Are You a Good Fit for This Trial?

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.

Timeline for a Trial Participant

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

What Are the Treatments Tested in This Trial?

Interventions

• Oxygen

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.

How Is the Trial Designed?

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+

National Eye Institute (NEI)

Collaborator

Trials

572

Recruited

1,320,000+

Vasoptic Medical, Inc

Collaborator

Trials

1

Recruited

150+

Published Research Related to This Trial

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 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]

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]

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]

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]

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 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]

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]

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 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]

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]

Citations

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Hyperbaric Oxygen Therapy in Ophthalmology: A Narrative ... The patients who received treatment within 12 h of symptom onset showed the most significant improvement. Although some patients experienced ...

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC5757969/

Glaucoma related retinal oximetry: a technology update - PMC This study also showed that there was no difference in the retinal oxygen saturation between healthy individuals and patients with glaucoma, ...

3. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0025556424001524

Predicting Retinal Vessel Density Impact on Oxygenation This study quantifies the impact of decreased vessel density on retinal tissue oxygenation. · The clinically observed reduction in vessel density by 10–13 % in ...

4. researchgate.net researchgate.net/publication/7178077_The_effect_of_hyperbaric_oxygen_on_intraocular_pressure

The effect of hyperbaric oxygen on intraocular pressure Our data indicated a statistically significant decrease in IOPs during therapy at 2.5 ATA. This decrease was of minor physiological ...

5. journals.lww.com journals.lww.com/jcor/fulltext/2025/04000/changes_in_the_intraocular_pressure_after.11.aspx

Changes in Intraocular Pressure After Hyperbaric Oxygen A single session of HBOT at 2.5 ATA done for 90 min has shown a decrease in IOP; although the difference is not statistically significant, the long-term effect ...

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC12452972/

Visual Outcomes Following Hyperbaric Oxygen Therapy in ... This retrospective study showed the efficacy and safety of HBOT in patients with CRAO who presented within 24 hours of symptom onset. Patients ...

7. frontiersin.org frontiersin.org/journals/medicine/articles/10.3389/fmed.2024.1365259/full

A deep dive into hyperbaric environments and intraocular ... This systematic review aims to consolidate recent literature findings regarding the impact of increased atmospheric pressure on IOP and glaucoma.