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Short-term effects on ocular variables immediately after hyperbaric oxygen exposures
Knut Evanger1, Guro Vaagbø2, Olav H Haugen1,3
1Department of Clinical Medicine, Faculty of Medicine, University of Bergen, Bergen, Norway.
Purpose:
To determine ocular refraction, corneal thickness, corneal radius, corneal power, corneal astigmatism and intraocular pressure in patients before and immediately after repeated hyperbaric oxygen (HBO2) exposures twice a week during six weeks of HBO2 therapy.
Methods:
23 patients received HBO2 therapy at 2.4 ATA for 90 minutes daily in monoplace chambers for six weeks, five days a week. The Topcon TRK-1P instrument was installed next to the hyperbaric chambers to record the ocular measurements.
Results:
A gross myopic shift developed at -0.95 ± 0.54 D (P ⟨ 0.001) in the right eye and -0.95 ± 0.53 D (P ⟨ 0.001) in the left eye during the six weeks of treatment. Myopic shift reversion, corneal thinning and reduced intraocular pressure appeared as immediate effects after a single HBO2 exposure, but resolved before the patients attended for the next measurement visit.
Conclusions:
Ocular variables were influenced by both cumulative and transient short-term effects during the HBO2 therapy. The short-term effects showed that the point of time for performing the ocular measurements after HBO2 exposure might influence the result and must be considered before making relevant comparisons among studies.
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