The effect of corneal contact lenses on the oxygen tension in the anterior chamber of the rabbit eye.

The oxygen tension in the aqueous humor in the anterior chamber of rabbit eyes was measured continuously with a polarographic electrode. The normal oxygen tension in the anterior chamber was 23 +/- 2 mm Hg (mean +/- SD, n = 4). A contact lens was then placed on the cornea for at least 10 min and the drop in oxygen tension recorded. A hard polymethylmethacrylate lens reduced the oxygen tension by 16 +/- 4 mm Hg, and a larger hydroxyethylmethacrylate soft lens (Soflens) decreased oxygen tension by 17 +/- 4 mm Hg (mean +/- SD, n = 4). Comparable statistically significant decreases were seen with the Permalens, Polycon II, and Silcon lenses. Only the elastofilcon A lens (Silsoft) did not decrease the oxygen tension in the anterior chamber significantly.