How graded forced exhalation affects intraocular (eye) pressure
The Effect of Graded Forced Expiration on Intraocular Pressure: A Study Using the Airofit Device
We will test whether controlled levels of forced exhalation using an Airofit device change eye pressure in adults with healthy optic nerves.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 60 (estimated) |
| Ages | 18 Years to 65 Years |
| Sex | All |
| Sponsor | Uşak University Academic / other |
| Locations | 1 site (Uşak) |
| Trial ID | NCT07274176 on ClinicalTrials.gov |
What this trial studies
This interventional protocol uses the Airofit respiratory trainer to deliver six predefined levels of forced expiration while measuring intraocular pressure (IOP). Adult participants with good visual acuity and normal optic nerve appearance will perform the graded expiratory maneuvers under supervision while IOP is recorded at each level. The study aims to produce reproducible, quantitative data on the relationship between respiratory effort and transient IOP changes to create a standardized measurement paradigm. Findings will clarify how different magnitudes of expiratory force influence IOP dynamics and inform future research and clinical guidance.
Who should consider this trial
Good fit: Adults aged 18 or older with best-corrected visual acuity of 6/12 or better, optic nerve cup/disc ratio ≤ 0.5, no recent systemic or ocular medications affecting IOP, and able to use the Airofit device are ideal candidates.
Not a fit: Patients with a history of intraocular surgery, uveitis, significant refractive error (>±3D), ongoing topical glaucoma treatment, or other ocular pathology are unlikely to benefit or be eligible.
Why it matters
Potential benefit: If successful, the work could give clinicians objective data to predict and manage short-term IOP spikes during respiratory maneuvers and improve safety guidance.
How similar studies have performed: Maximal Valsalva effects on IOP are known, but studies using graded, precisely controlled expiratory resistance are limited, making this a relatively novel methodological approach.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Aged 18 years or older. * Willing and able to provide informed consent. * Have a best-corrected visual acuity of 6/12 or better. * Able to understand and follow instructions for using the Airofit device. * Have an optic nerve cup/disc ratio not exceeding 0.5, and have a c/d difference between both eyes not exceeding 0.2. * Did not have taken any anticholinergic medication, systemic beta-blockers, or corticosteroids within the last 3 months that could affect intraocular pressure levels. Exclusion Criteria: * a history of intraocular surgery, * a history of uveitis, * a spherical refractive error exceeding 3D, * a history of regular topical treatment other than artificial tears
Where this trial is running
Uşak
- University of Usak — Uşak, Turkey (Türkiye) (Recruiting)
Study contacts
- Study coordinator: Ata Baytaroglu, Asst. Prof.
- Email: ata.baytaroglu@usak.edu.tr
- Phone: +905379315396
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.