Intraocular Pressure During Static Apnea

NCT07604428 | Completed

• 1 other identifier: 103/26
• Study Type: observational
• Target: 40
• Locations: 1 country
• Sites: 1

Brief 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 apnea, and after apnea. The aim was to assess the magnitude and dynamics of IOP changes and their relationship to physiological parameters.

Conditions

Glaucoma; Intraocular Pressure; Apnea

Keywords

Freediving; breath-hold diving; static apnea; intraocular pressure; glaucoma

Outcome Measures

Primary Outcomes (1)

• Change in intraocular pressure during dry static apnea

  Difference between baseline intraocular pressure and maximal intraocular pressure during apnea

  Baseline, during apnea and within 30 and 60 seconds after apnea

Secondary Outcomes (3)

• Blood pressure changes

  Before apnea, during apnea and within 60 and 120 seconds after apnea

• Heart rate changes

  Baseline, during apnea and within 30 and 60 seconds after apnea

• Peripheral oxygen saturation changes

  Baseline, during apnea and within 30 and 60 seconds after apnea

Study Arms (1)

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.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Adult amateur and professional breath-hold divers

You may qualify if:

• age over 18 years
• breath-hold divers at the amateur or professional level
• signed informed consent

You may not qualify if:

• 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

Sponsors & Collaborators

• University Hospital Olomouc: lead
• Palacky University: collaborator
• Lensi Turnov s.r.o.: collaborator

Study Sites (1)

Department of Ophthalmology, University Hospital Olomouc, Olomouc

Olomouc, 77900, Czechia

Location

MeSH Terms

Conditions

Glaucoma; Apnea

Condition Hierarchy (Ancestors)

Ocular Hypertension; Eye Diseases; Respiration Disorders; Respiratory Tract Diseases; Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Pavla Potesilova, MD

  Lensi Turnov s.r.o.

  PRINCIPAL INVESTIGATOR

• Marta Karhanova, MD, PhD, FEBO

  University Hospital Olomouc and Palacky University Olomouc

  STUDY DIRECTOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 17, 2026
• First Posted: May 22, 2026
• Study Start: January 1, 2018
• Primary Completion: March 31, 2019
• Study Completion: March 31, 2019
• Last Updated: May 22, 2026

Record last verified: 2026-05

Locations

CZ (1)