GlaucomaNCT07604428
Intraocular Pressure During Static Apnea
An observational study of Glaucoma and Intraocular Pressure, run by University Hospital Olomouc at 1 site in Czechia.
Trial summary
This prospective observational study evaluated changes in intraocular pressure (IOP) during dry static apnea (STA) in breath-hold divers. Forty participants performed voluntary breath-holds while intraocular pressure, peripheral oxygen saturation (SpO2), heart rate, and blood pressure were measured at baseline, during… Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Glaucoma, Intraocular Pressure, Apnea
- How many people
- 40 participants
- Where
- 1 siteCzechia
- Study dates
- 1 Jan 2018to 31 Mar 2019
- Phase
- Observational
- Are there results?
- None posted in the registry
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 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Adult amateur and professional breath-hold divers
Who may be able to join
- age over 18 years
- breath-hold divers at the amateur or professional level
- signed informed consent
Who cannot join
- known intraocular hypertension or glaucoma
- refractive error > ±5.00 D
- history of an eye injury
- previous surgery for cataract, strabismus, or pars plana vitrectomy
- corneal disease
- acute eye infection
Trial locations and contacts
1 site in 1 country.
Czechia1 site
Department of Ophthalmology, University Hospital Olomouc, Olomouc
Olomouc, 77900
About this study
Official title: Intraocular Pressure Changes During Dry Static Apnea in Breath-Hold Divers
This prospective observational study evaluated changes in intraocular pressure (IOP) during dry static apnea (STA) in breath-hold divers. Forty participants performed voluntary breath-holds while intraocular pressure, peripheral oxygen saturation (SpO2), heart rate, and blood pressure were measured at baseline, during apnea, and after apnea. The aim was to assess the magnitude and dynamics of IOP changes and their relationship to physiological parameters.
Read the detailed description
Breath-hold diving is associated with marked physiological changes, including hypoxemia, hypercapnia, bradycardia, and increases in blood pressure. The effect of prolonged breath-holding on intraocular pressure (IOP) remains insufficiently understood.
This prospective observational study investigated changes in intraocular pressure during dry static apnea (STA) in adult breath-hold divers. Participants performed breath-holds in a supine position after a standardized resting period.
Intraocular pressure was measured using a rebound tonometer (Icare Pro, Icare Finland Oy, Helsinki, Finland). Blood pressure was measured using an automated sphygmomanometer (Omron M6 Comfort, Omron Healthcare, Kyoto, Japan). Peripheral oxygen saturation and heart rate were continuously monitored using a pulse oximeter (Beurer PO 80, Beurer Healthcare, Germany).
Measurements were obtained at baseline, during apnea and after resumption of breathing.
The primary objective was to quantify changes in intraocular pressure during STA. Secondary objectives included assessment of physiological responses and analysis of their relationship with IOP changes.
- Conditions
- Glaucoma, Intraocular Pressure, Apnea
- Keywords
- Freediving, breath-hold diving, static apnea, intraocular pressure, glaucoma
- Medical subject headings
- Glaucoma, Apnea
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Breath-hold divers | Adult amateur and professional breath-hold divers undergoing dry static apnea with repeated assessment of intraocular pressure, blood pressure, heart rate, and oxygen saturation before, during, and after apnea. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in intraocular pressure during dry static apnea
Difference between baseline intraocular pressure and maximal intraocular pressure during apnea
Measured: Baseline, during apnea and within 30 and 60 seconds after apnea
Secondary outcomes (3)
Blood pressure changes
Changes in systolic, diastolic, and mean arterial pressure during dry static apnea
Measured: Before apnea, during apnea and within 60 and 120 seconds after apnea
Heart rate changes
Changes in heart rate during dry static apnea
Measured: Baseline, during apnea and within 30 and 60 seconds after apnea
Peripheral oxygen saturation changes
Changes in peripheral oxygen saturation during dry static apnea
Measured: Baseline, during apnea and within 30 and 60 seconds after apnea
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 May 2026
- Study start1 Jan 2018
- Primary completion31 Mar 2019
- Study completion31 Mar 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for GlaucomaStudies of the same condition, open and under way.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Hospital Olomouc
- Sponsor type
- University, hospital or other
- Collaborators
- Palacky University, Lensi Turnov s.r.o.
- Responsible party
- Sponsor
- Investigators
- Pavla Potesilova, MD, Principal investigator, Lensi Turnov s.r.o.Marta Karhanova, MD, PhD, FEBO, Study director, University Hospital Olomouc and Palacky University Olomouc
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07604428
- Sponsor's protocol ID
- 103/26
- Status last verified
- May 2026
- First submitted
- 17 May 2026
- Last updated
- 22 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 22 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Intraocular Pressure Changes During Dry Static Apnea in Breath-Hold Divers
- ClinicalTrials.gov ID
- NCT07604428
- Acronym / sponsor ID
- 103/26
- Conditions
- Glaucoma, Intraocular Pressure, Apnea
- Keywords
- Freediving, breath-hold diving, static apnea, intraocular pressure, glaucoma
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- University Hospital OlomoucUniversity, hospital or other
- Collaborators
- Palacky University, Lensi Turnov s.r.o.
- Study start
- 1 Jan 2018 (actual)
- Primary completion
- 31 Mar 2019 (actual)
- Study completion
- 31 Mar 2019 (actual)
- First posted
- 22 May 2026 (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 prospective observational study evaluated changes in intraocular pressure (IOP) during dry static apnea (STA) in breath-hold divers. Forty participants performed voluntary breath-holds while intraocular pressure, peripheral oxygen saturation (SpO2), heart rate, and blood pressure were measured at baseline, during apnea, and after apnea. The aim was to assess the magnitude and dynamics of IOP changes and their relationship to physiological parameters.
Detailed description
Breath-hold diving is associated with marked physiological changes, including hypoxemia, hypercapnia, bradycardia, and increases in blood pressure. The effect of prolonged breath-holding on intraocular pressure (IOP) remains insufficiently understood.
This prospective observational study investigated changes in intraocular pressure during dry static apnea (STA) in adult breath-hold divers. Participants performed breath-holds in a supine position after a standardized resting period.
Intraocular pressure was measured using a rebound tonometer (Icare Pro, Icare Finland Oy, Helsinki, Finland). Blood pressure was measured using an automated sphygmomanometer (Omron M6 Comfort, Omron Healthcare, Kyoto, Japan). Peripheral oxygen saturation and heart rate were continuously monitored using a pulse oximeter (Beurer PO 80, Beurer Healthcare, Germany).
Measurements were obtained at baseline, during apnea and after resumption of breathing.
The primary objective was to quantify changes in intraocular pressure during STA. Secondary objectives included assessment of physiological responses and analysis of their relationship with IOP changes.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Breath-hold divers | – | –Adult amateur and professional breath-hold divers undergoing dry static apnea with repeated assessment of intraocular pressure, blood pressure, heart rate, and oxygen saturation before, during, and after apnea. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Adult amateur and professional breath-hold divers
Key inclusion criteria (3 listed)
- age over 18 years
- breath-hold divers at the amateur or professional level
- signed informed consent
Key exclusion criteria (6 listed)
- known intraocular hypertension or glaucoma
- refractive error > ±5.00 D
- history of an eye injury
- previous surgery for cataract, strabismus, or pars plana vitrectomy
- corneal disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Change in intraocular pressure during dry static apnea
Time frame: Baseline, during apnea and within 30 and 60 seconds after apnea
Difference between baseline intraocular pressure and maximal intraocular pressure during apnea
3 secondary outcomes
Blood pressure changes
Time frame: Before apnea, during apnea and within 60 and 120 seconds after apnea
Heart rate changes
Time frame: Baseline, during apnea and within 30 and 60 seconds after apnea
Peripheral oxygen saturation changes
Time frame: Baseline, during apnea and within 30 and 60 seconds after apnea
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 May 2026.
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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. This study is not recruiting at the moment.
Pavla Potesilova, MD principal investigator
Lensi Turnov s.r.o.
Marta Karhanova, MD, PhD, FEBO study director
University Hospital Olomouc and Palacky University Olomouc
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Glaucoma and Intraocular Pressure, run by University Hospital Olomouc at 1 site in Czechia.
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 3 inclusion and 6 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: finished, as of the sponsor's last update on 22 May 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 Czechia. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in intraocular pressure during dry static apnea (time frame: Baseline, during apnea and within 30 and 60 seconds after apnea). 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 22 May 2026.