Intraocular PressureNCT06275308
Effect of Raised End-Tidal pCo2 on Choroidal Volume
A study testing Ventilation manipulation in people with Intraocular Pressure, run by University of Pittsburgh at 1 site in United States.
Trial summary
This study is to investigate the relationship between arterial carbon dioxide (CO2) concentration and vitreous pressure on the choroidal volume by integrated intraoperative OCT imaging under eye exams under anesthesia. Read more about this study
- Who is it for?
- Ages Up to 8 yearsHealthy volunteers can take part
- Conditions the study is for
- Intraocular Pressure
- What is being tested?
- Ventilation manipulation
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 27 Feb 2023to 30 Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Up to 8 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- any child undergoing an eye exam under anesthesia for an ophthalmologic reason.
- children between the ages newborn to 8 years of age.
Who cannot join
- children who are not having an eye exam under anesthesia.
- children with a known medical diagnosis that affect the eye to be studied
- * children over the age of 8 years of age.
- * children with altered cerebral autoregulation, increased intracranial pressure, pulmonary hypertension, or any other condition deemed appropriate by the anesthesiologist.
- children in whom a laryngeal mask airway will not be used
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Pittsburgh Medical Center
Pittsburgh, Pennsylvania, 15224
Amy Monroe, MPH, MBA, monroeal@upmc.edu
Kanwal Nischal, MD,FRCOphth
About this study
This study is to investigate the relationship between arterial carbon dioxide (CO2) concentration and vitreous pressure on the choroidal volume by integrated intraoperative OCT imaging under eye exams under anesthesia.
Read the detailed description
Children with normal eyes undergoing an exam under anesthesia or a non-intraocular eye procedure will have one eye examined after research consent is taken. Children have very elastic ocular tissues. When they are having an intraocular procedure positive vitreous pressure can cause the iris to prolapse out of the eye and this can cause intraoperative and postoperative complications. The causes of the positive vitreous pressure have been speculated to be due to an increase in choroidal volume. The Choroid is a layer of blood vessels sitting between the sclera and the retina. Ocular Coherence Tomography (OCT) is an imaging tool that allows an optical section of the retina, choroid and sclera to be examined. The subfoveal choroidal thickness has been shown to be a consistent area that can be measured with reliability that the anatomical site of measurement is consistent. By varying the end tidal CO2 the thickness of the choroid will be measured and at the same time the intraocular pressure taken using a pneumatonometer. The OCT is integrated into the operating microscope and is used to take a scan of the fovea. Three scans will be taken after 5minutes of the particular end tidal pCO2. In order to ensure the choroidal thickness is not being influenced by the axial length of the eye, the axial length will be measured using an ultrasound probe at the beginning of the measurements just once. In order to ensure that the position of the head and body is not influencing the choroidal thickness a spirit level will be used to ensure a flat operating bed at the beginning of the measurements.
- Conditions
- Intraocular Pressure
- Being tested
- Ventilation manipulation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ventilation manipulationOther
Effects of ventilation manipulation to achieve desired levels of end tidal carbon dioxide
| Study group | Role | What they receive |
|---|---|---|
| Observational Group | Experimental | Manipulation of end tidal carbon dioxide in subjects Receives: Other: Ventilation manipulation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Intraocular Pressure (IOP) (mmHg)
Measurement of intraocular pressure after maintenance of end tidal pCO2 for 5 minutes at three end tidal pCO2 values : 40mmHg, then 30mmHg and then 50mmHg
Measured: After induction of anesthesia end tidal CO2 will be manipulated to 40mmHg, then 30mmHg and then 50mmHg. The end tidal CO2 levels will be held for at least 5 minutes after each ventilation manipulation and at the end of this 5 minute period IOP measured
Secondary outcomes (1)
Choroidal thickness ( microns)
After 5 minutes of maintenance of end tidal pCO2 at 40mmHg, then 30mmHg and then 50mmHg, ocular coherence tomography (OCT) will be used to capture the subfoveal choroid. The images of the choroid will be provided to blinded individuals who will measure their thickness using the integrated scale on the OCT image.
Measured: After induction of anesthesia end tidal CO2 will be manipulated to 40mmHg, then 30mmHg and then 50mmHg. The end tidal CO2 levels will be held for at least 5 minutes after each ventilation manipulation;at the end of 5 minute period choroid images taken
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Feb 2024
- Study start27 Feb 2023
- Primary completion30 Dec 2026 (estimated)
- Study completion30 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Intraocular PressureStudies of the same condition, open and under way.
- More trials run by University of PittsburghThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- This is a descriptive case series.
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Pittsburgh
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Kanwal Nischal, University of Pittsburgh
- Investigators
- Amy Monroe, MPH, MBA, Study director, University of PittsburghKanwal Nischal, MD,FRCOphth, Principal investigator, University of Pittsburgh
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06275308
- Sponsor's protocol ID
- STUDY21100163
- Status last verified
- Jan 2026
- First submitted
- 24 Jan 2024
- Last updated
- 9 Jan 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Raised End-Tidal pCo2 on Choroidal Volume
- ClinicalTrials.gov ID
- NCT06275308
- Acronym / sponsor ID
- STUDY21100163
- Conditions
- Intraocular Pressure
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- University of PittsburghUniversity, hospital or other
- Study start
- 27 Feb 2023 (actual)
- Primary completion
- 30 Dec 2026 (estimated)
- Study completion
- 30 Dec 2026 (estimated)
- First posted
- 23 Feb 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is to investigate the relationship between arterial carbon dioxide (CO2) concentration and vitreous pressure on the choroidal volume by integrated intraoperative OCT imaging under eye exams under anesthesia.
Detailed description
Children with normal eyes undergoing an exam under anesthesia or a non-intraocular eye procedure will have one eye examined after research consent is taken. Children have very elastic ocular tissues. When they are having an intraocular procedure positive vitreous pressure can cause the iris to prolapse out of the eye and this can cause intraoperative and postoperative complications. The causes of the positive vitreous pressure have been speculated to be due to an increase in choroidal volume. The Choroid is a layer of blood vessels sitting between the sclera and the retina. Ocular Coherence Tomography (OCT) is an imaging tool that allows an optical section of the retina, choroid and sclera to be examined. The subfoveal choroidal thickness has been shown to be a consistent area that can be measured with reliability that the anatomical site of measurement is consistent. By varying the end tidal CO2 the thickness of the choroid will be measured and at the same time the intraocular pressure taken using a pneumatonometer. The OCT is integrated into the operating microscope and is used to take a scan of the fovea. Three scans will be taken after 5minutes of the particular end tidal pCO2. In order to ensure the choroidal thickness is not being influenced by the axial length of the eye, the axial length will be measured using an ultrasound probe at the beginning of the measurements just once. In order to ensure that the position of the head and body is not influencing the choroidal thickness a spirit level will be used to ensure a flat operating bed at the beginning of the measurements.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- This is a descriptive case series.
| Arm | Type | Receives |
|---|---|---|
| Observational Group | Experimental | Other: Ventilation manipulationManipulation of end tidal carbon dioxide in subjects |
Who may qualify
- Ages
- Up to 8 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (2 listed)
- any child undergoing an eye exam under anesthesia for an ophthalmologic reason.
- children between the ages newborn to 8 years of age.
Key exclusion criteria (5 listed)
- children who are not having an eye exam under anesthesia.
- children with a known medical diagnosis that affect the eye to be studied
- * children over the age of 8 years of age.
- * children with altered cerebral autoregulation, increased intracranial pressure, pulmonary hypertension, or any other condition deemed appropriate by the anesthesiologist.
- children in whom a laryngeal mask airway will not be used
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Ventilation manipulationEffects of ventilation manipulation to achieve desired levels of end tidal carbon dioxide | Other | Observational Group |
Primary outcome
Intraocular Pressure (IOP) (mmHg)
Time frame: After induction of anesthesia end tidal CO2 will be manipulated to 40mmHg, then 30mmHg and then 50mmHg. The end tidal CO2 levels will be held for at least 5 minutes after each ventilation manipulation and at the end of this 5 minute period IOP measured
Measurement of intraocular pressure after maintenance of end tidal pCO2 for 5 minutes at three end tidal pCO2 values : 40mmHg, then 30mmHg and then 50mmHg
1 secondary outcome
Choroidal thickness ( microns)
Time frame: After induction of anesthesia end tidal CO2 will be manipulated to 40mmHg, then 30mmHg and then 50mmHg. The end tidal CO2 levels will be held for at least 5 minutes after each ventilation manipulation;at the end of 5 minute period choroid images taken
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Jan 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Amy Monroe, MPH, MBA study director
University of Pittsburgh
Kanwal Nischal, MD,FRCOphth principal investigator
University of Pittsburgh
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ventilation manipulation in people with Intraocular Pressure, run by University of Pittsburgh at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 9 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Amy Monroe, MPH, MBA (412-623-6382 ext. 6382, monroeal@upmc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Intraocular Pressure (IOP) (mmHg) (time frame: After induction of anesthesia end tidal CO2 will be manipulated to 40mmHg, then 30mmHg and then 50mmHg. The end tidal CO2 levels will be held for at least 5 minutes after each ventilation manipulation and at the end of this 5 minute period IOP measured). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Jan 2026.