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. 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. 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. 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.

Evanger, Vaagbø, Haugen (2018). Short-term effects on ocular variables immediately after hyperbaric oxygen exposures. Undersea & hyperbaric medicine : journal of the Undersea and Hyperbaric Medical Society, Inc, ;45(4):395-402. https://www.ncbi.nlm.nih.gov/pubmed/30241118