The effect of hyperbaric oxygen on intraocular pressure.

The effects of hyperoxia on intraocular pressure (IOP) have been studied in experiments on human beings and animals. The changes occurring in IOP in patients during routine HBO2 therapy are unknown. In this study we investigated IOP changes arising during the HBO2 therapy at 2.5 ATA. Fifty-six patients receiving HBO2 therapy for various reasons were included in the study. Bilateral IOPs of patients measured with the Tono-pen XL (Medtronic, Solan, USA) tonometer before, during and after HBO2 therapy. Average IOPs were 14.85 +/- 3.17 mmHg (range, 10-24), 13.00 +/- 2.97 mmHg (range, 9-21) and 14.74 +/- 3.12 mmHg (range, 10-22), respectively. IOP was reduced significantly during HBO2 therapy and returned its pre- HBO2 levels after therapy. Our data indicated a statistically significant decrease in IOPs during therapy at 2.5 ATA. This decrease was of minor physiological significance in these patients whose baseline IOP values were within the normal range.