What Researchers Did
Mexican researchers measured intraocular pressure (IOP) with two tonometers in 22 healthy volunteers at four different atmospheric pressure levels inside a hyperbaric chamber to see how pressure changes affect eye pressure readings.
What They Found
Both Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT) showed changes in IOP measurements as atmospheric pressure changed. GAT and DCT readings diverged in different directions, with the difference between instruments increasing by roughly 1 mmHg per 673 metres of altitude gain. Neither instrument maintained consistent accuracy across pressure levels.
What This Means for Canadian Patients
For Canadian glaucoma patients or patients with eye conditions who need HBOT, this study suggests IOP monitoring inside a hyperbaric chamber requires careful interpretation, as standard tonometers may give inaccurate readings under pressure.
Canadian Relevance
No direct Canadian connection identified. Ophthalmologists overseeing HBOT patients with glaucoma should be aware that routine IOP measurement methods may not be reliable inside a hyperbaric chamber.
Study Limitations
The study included only 22 volunteers tested at modest pressure increases well below typical HBOT levels (2-3 ATA), and results may not apply to full therapeutic hyperbaric pressures.