Effect of Raised End-Tidal pCo2 on Choroidal Volume

Intraocular Pressure Clinical Trial

Official title:

Effect of Raised End-Tidal pCo2 on Choroidal Volume

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT06275308
• Other study ID #: STUDY21100163
• Status: Recruiting
• Phase: N/A
• Start date: February 27, 2023
• Est. completion date: February 27, 2025

Study information

• Verified date: February 2024
• Source: University of Pittsburgh
• Contact: Amy Monroe, MPH, MBA
• Phone: 412-623-6382
• Email: monroeal[@]upmc.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical 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.

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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 20
• Est. completion date: February 27, 2025
• Est. primary completion date: February 27, 2025
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: N/A to 8 Years

Eligibility

Inclusion Criteria:

• any child undergoing an eye exam under anesthesia for an ophthalmologic reason.

• children between the ages newborn to 8 years of age.

Exclusion Criteria:

• children who are not having an eye exam under anesthesia.

• * children over the age of 8 years of age.

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

Related Conditions & MeSH terms

• Intraocular Pressure

Intervention

Other:
• Ventilation manipulation
Effects of ventilation manipulation to achieve desired levels of end tidal carbon dioxide

Locations

Country	Name	City	State
United States	University of Pittsburgh Medical Center	Pittsburgh	Pennsylvania

Sponsors (1)

Lead Sponsor	Collaborator
University of Pittsburgh

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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	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	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.	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