RESUMEN
Our purpose was to investigate the quality and morphology of cultured bovine lenses after exposure to hyperbaric oxygen (HBO) in the presence or absence of desferrioxamine (DFO) or zinc-desferrioxamine (Zn-DFO). Intact bovine lenses were cultured and exposed to HBO of 100% oxygen at 2.5 ATA for 120 min. One hundred and fifty lenses were included in the present study. Lenses were divided into study groups of 25 lenses each: (1a) HBO-exposed lenses; (1b) control lenses extracted from the contralateral eyes of group 1a and exposed to normal room air. (2a) HBO-exposed lenses treated with DFO; (2b) control lenses extracted from the contralateral eyes of group 2a exposed to normal room air in the presence of DFO (3a) HBO-exposed lenses treated with Zn-DFO; (3b) control lenses extracted from the contralateral eyes of group 3a, exposed to normal room air in the presence of Zn-DFO. Lens optical quality and structural changes were assessed. Oxygen toxicity to lenses was demonstrated by decreased light transmission, increase in focal length variability and a decrease in morphological integrity. Light intensity measurements showed a distinct pattern in control lenses. A different pattern was noticed for hyperbaric oxygen-exposed lenses. Focal length variability values were stable in control lenses and increased significantly in oxygen-exposed lenses. Structural damage to lenses was demonstrated by the appearance of bubbles between lens' fibers possibly demonstrating failure of lens tissue to cope with oxygen load. All measured parameters showed that both Zn-DFO and DFO attenuated the oxidative damage. The effect of DFO was small whereas Zn-DFO demonstrated a significantly stronger effect. Treatment of hyperbaric oxygen-exposed lenses with DFO only marginally reduced the oxidative damage. Treatment with Zn-DFO was superior in reducing the oxidative damage to lenses. These results indicate a possible role for Zn-DFO in the prevention of cataracts.