Ventilation Manipulation for Glaucoma

Overseen By Alisha Maslanka, BS, CCRC

Age: < 18

Sex: Any

Trial Phase: Academic

Sponsor: University of Pittsburgh

Disqualifiers: Altered cerebral autoregulation, increased intracranial pressure, pulmonary hypertension, others

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

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 1

Duration: 1 day

20 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how adjusting breathing (ventilation manipulation) during eye exams under anesthesia might affect eye pressure and blood flow in children. The researchers aim to understand the link between carbon dioxide levels in the blood and eye pressure, using special imaging techniques during the procedure. The study seeks children already scheduled for eye exams under anesthesia for medical reasons. Children with conditions like altered brain blood flow or high eye pressure may not be eligible.

As an unphased study, this trial offers a unique opportunity to contribute to important research that could enhance future eye care for children.

Will I have to stop taking my current medications?

The trial information does not specify whether participants need to stop taking their current medications.

What prior data suggests that ventilation manipulation is safe for glaucoma patients?

Research shows that altering ventilation can affect eye pressure, which is crucial for vision. Studies indicate that excessive ventilation pressure might raise intraocular pressure. However, using lower pressures, like 5 to 6 cmH2O, generally does not significantly increase this pressure.

These findings suggest the importance of carefully controlling ventilation levels for safety. While higher pressures might pose risks, treatment at lower levels appears well-tolerated. Studies using lower ventilation pressures have reported no major side effects.

Overall, while high pressure requires caution, studies suggest that controlled ventilation changes have a good safety record regarding eye pressure. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Most treatments for glaucoma focus on reducing intraocular pressure through medications, laser treatments, or surgery. However, ventilation manipulation is unique because it explores the effect of altering end tidal carbon dioxide levels on eye health. Researchers are excited about this approach because it targets a physiological process not typically addressed in glaucoma care, potentially offering a novel way to manage the disease. By investigating this new angle, researchers hope to uncover insights that could lead to alternative treatment strategies for glaucoma patients.

What evidence suggests that ventilation manipulation is effective for glaucoma?

Research shows that breathing patterns can impact the pressure inside the eyes. In this trial, participants will join an observational group to study the manipulation of end tidal carbon dioxide. Mechanical ventilation, which uses machines to assist breathing, can increase eye pressure. This is important because high eye pressure is a major risk factor for glaucoma, a condition that can harm vision. Some studies have found that increased breathing pressure can significantly raise eye pressure. This suggests that managing breathing might help control eye pressure in people with glaucoma. ^{1 2 4 6 7}

Who Is on the Research Team?

Kanwal Nischal, MD,FRCOphth

Principal Investigator

University of Pittsburgh

Amy Monroe, MPH, MBA

Principal Investigator

University of Pittsburgh

Are You a Good Fit for This Trial?

This clinical trial is for children from newborns up to 8 years old who are already scheduled for an eye exam under anesthesia due to ophthalmologic reasons. It's not suitable for kids over 8, those with conditions affecting brain blood flow regulation, increased pressure inside the skull, or any issues the anesthesiologist thinks could cause problems.

Inclusion Criteria

My child needs an eye exam under anesthesia for an eye condition.

My child is between newborn and 8 years old.

Exclusion Criteria

I am over 8 years old.

Children with altered cerebral autoregulation, increased intracranial pressure, or any other condition deemed appropriate by the anesthesiologist.

Children who are not having an eye exam under anesthesia

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Treatment

Manipulation of end tidal carbon dioxide in subjects to measure intraocular pressure and choroidal thickness

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

2 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Ventilation manipulation

Trial Overview

The study is examining how changing the amount of carbon dioxide (CO2) in a child's breath affects the thickness of part of their eye called the choroid. This will be done using special imaging during an eye exam while they're under anesthesia.

How Is the Trial Designed?

Group I: Observational Group Experimental Treatment 1 Intervention

Manipulation of end tidal carbon dioxide in subjects

Who Is Running the Clinical Trial?

University of Pittsburgh

Lead Sponsor

Trials

1,820

Recruited

16,360,000+

Published Research Related to This Trial

In a study involving six subjects, mechanical ventilation at low peak inspiratory pressures did not significantly affect intraocular pressure (IOP), suggesting it may be safe in this context.

However, using high peak inspiratory pressures during mechanical ventilation resulted in a significant increase in IOP (32.7% higher), indicating that patients on long-term mechanical ventilation at high pressures could be at risk for vision impairment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Intraocular pressure and mechanical ventilation. Johnson, DS., Crittenden, DJ.[2019]

Invasive bi-level positive airway pressure ventilation significantly reduces the oxygen cost of breathing by about 15% in post-polio patients compared to conventional controlled mechanical ventilation (CMV).

The study involved nine post-polio patients and confirmed that the Harris-Benedict equation accurately predicts energy expenditure, indicating that bi-level ventilation may enhance respiratory efficiency in this population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Bi-level positive airway pressure ventilation reduces the oxygen cost of breathing in long-standing post-polio patients on invasive home mechanical ventilation. Barle, H., Söderberg, P., Haegerstrand, C., et al.[2005]

In a study of 17 patients with glaucoma and extremely shallow anterior chambers, combined 23-gauge pars plana vitrectomy and lensectomy significantly reduced intraocular pressure from an average of 43.14 mmHg to 17.29 mmHg, indicating effective management of glaucoma.

The procedure also increased the anterior chamber depth from 0.507 mm to 3.080 mm and reduced the need for anti-glaucoma medications from an average of 4.1 to 0.6, demonstrating both safety and efficacy without severe complications.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Surgical outcomes of 23-gauge transconjunctival pars plana vitrectomy combined with lensectomy for glaucomatous eyes with extremely shallow anterior chamber and cataract. Zhang, Z., Zhang, S., Jiang, X., et al.[2018]

In a study involving 30 patients, short-term use of positive end-expiratory pressure (PEEP) at levels of 15 cm H2O or lower does not significantly increase intraocular pressure, indicating it is safe for patients with normal eye pressure.

While prolonged mechanical ventilation with PEEP may lead to slight increases in intraocular pressure, these changes are not clinically significant, suggesting that PEEP can be used without major concerns for ocular hypertension in critically ill patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Intraocular pressure during mechanical ventilation with different levels of positive end-expiratory pressure. Teba, L., Viti, A., Banks, DE., et al.[2019]

In patients with acute cardiogenic pulmonary edema, continuous positive airway pressure (CPAP) significantly reduces mortality compared to standard therapy, with a relative risk of 0.59 based on 23 trials.

Both CPAP and bilevel ventilation effectively lower the need for invasive mechanical ventilation compared to standard therapy, but no significant difference in mortality was found between CPAP and bilevel ventilation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of non-invasive positive pressure ventilation (NIPPV) on mortality in patients with acute cardiogenic pulmonary oedema: a meta-analysis. Peter, JV., Moran, JL., Phillips-Hughes, J., et al.[2023]

Filtrating vitrectomy, a new surgical technique for treating neovascular glaucoma, was performed on 46 eyes and successfully normalized intraocular pressure without medication in 70% of cases shortly after surgery.

In the long term (12-39 months), 66% of cases maintained normalized intraocular pressure, demonstrating the procedure's efficacy in managing this condition.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Experience in the surgical treatment of neovascular diabetic glaucoma]. Nesterov, AP., Batmanov, IuE., Serov, AA.[2006]

The blitz anesthesia technique was successfully used in 15 non-English speaking patients during glaucoma surgery, providing adequate pain control and comfort without complications.

This method, which included a phonetic language diagram for communication, significantly reduced patient anxiety and helped patients feel reassured by understanding basic information from the surgical team.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Blitz Anesthesia Technique in Non-English Speaking Patients Undergoing Glaucoma Surgery. Almodin, J., Ichhpujani, P., Prasad, A., et al.[2022]

Noninvasive glaucoma procedures (NIGPs) offer a promising alternative to traditional invasive surgeries and medications, providing effective treatment options with fewer serious complications.

Common NIGPs, such as various laser therapies, have shown good efficacy and are now utilized as both primary and adjunctive therapies for managing glaucoma.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Noninvasive glaucoma procedures: current options and future innovations. Abdelrahman, AM.[2018]

In a study of 40 COPD patients with type 2 respiratory failure, non-invasive mechanical ventilation (NIMV) significantly increased intraocular pressure (IOP) after treatment, indicating a potential risk for patients with pre-existing eye conditions.

The study also suggested a trend towards decreased central corneal thickness (CCT) after NIMV treatment, highlighting the need for careful monitoring of eye health in patients receiving this type of respiratory support.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effects of non-invasive mechanic ventilator modes on intraocular pressure in COPD patients with hypercapnic respiratory failure. Aytekin, F., Yildiz Gulhan, P., Teberik, K., et al.[2020]

A new surgical method for treating secondary glaucoma was tested on 7 patients (8 eyes) aged 13-70, focusing on regulating eye pressure, relieving pain, and preserving eye function.

Preliminary results showed positive outcomes in all cases after up to 6 months of follow-up, indicating the method's potential effectiveness in managing secondary glaucoma.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Sinusotrabeculectomy with regulated filtration in the treatment of secondary glaucoma]. Barashkov, VI., Dushin, NV., Beliaev, VS., et al.[2018]

Citations

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pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC9318682/

Effects of Positive End-Expiratory Pressure on Intraocular ...

Background and Objectives: The effect of positive end-expiratory pressure (PEEP) on intraocular pressure (IOP) is debatable.

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clinicaltrials.gov

clinicaltrials.gov/study/NCT07188922

Effect of Transition From Mechanical Ventilation to ...

This prospective, single-center observational study aims to evaluate the acute effects of transitioning from mechanical ventilation to spontaneous breathing ...

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journal.chestnet.org

journal.chestnet.org/article/S0012-3692(16)00784-4/fulltext

Effects of Positive Pressure Ventilation on Glaucoma

METHODS: A retrospective analysis of two cases of glaucoma induced by positive pressure mechanical ventilation and literature review was conducted. RESULTS ...

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withpower.com

withpower.com/trial/phase-intraocular-pressure-iop-1-2023-587c9?condition=&query=Diazoxide&overallStatus=Recruiting&hasNoPlacebo=false

Ventilation Manipulation for Glaucoma

Research shows that mechanical ventilation can affect intraocular pressure (IOP), with high pressure ventilation increasing IOP significantly. This suggests ...

5.

pubmed.ncbi.nlm.nih.gov

pubmed.ncbi.nlm.nih.gov/8355962/

Intraocular pressure and mechanical ventilation

Mechanical ventilation increases superior vena cava pressure and should theoretically increase episcleral venous pressure and intraocular pressure (IOP).

6.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC6455825/

Effects of positive end-expiratory pressure on intraocular ...

At 5 cmH2O PEEP in cats, there was no significant change in IOP while the IOP increased significantly at 10 and 15 cmH2O PEEP. And length of ...

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mdpi.com

mdpi.com/1648-9144/58/7/940

Effects of Positive End-Expiratory Pressure on Intraocular ...

Applying 6 cmH 2 O of PEEP did not increase IOP but enhanced dynamic compliance and oxygenation during OLV. These results suggest that 6 cmH 2 O of PEEP can be ...