Oxygen effect on ocular lens

Background: Cataract is the leading cause of preventable blindness worldwide. Clinical observations and laboratory results have shown that oxygen has a possible toxic role in cataract formation. Aim: The aim of the present study was to demonstrate, measure and characterize the damage caused to bovine lenses in organ culture as a result of their exposure to hyperbaric oxygen pressure. Materials and Methods: Twenty bovine lenses exposed to hyperbaric pressure were compared to 20 control lenses. Lenses were kept in an organ culture for 14 days. Each day the focusing ability of the exposed lenses was compared to controls. The comparison was based on the amount to which the focus point of each measured ray diverged from the focus point of the lens. Lenses were also examined under the microscope and morphologic changes in study lenses were compared to controls. Results: A statistically significant difference in focusing ability between the study and control lenses was observed. The difference became larger during the incubation period indicating an accumulation of damage. The damage resulted from the peripheral but not the central part of the lenses. The morphologic changes observed under the microscope matched the damage profile of the focusing ability. Conclusions: Oxygen has a possible role in cataract formation. The effect of oxygen is cumulative. The route of damage formation follows the diffusion of oxygen into the lens.