The effects of ionizing irradiation on lens cation permeability, transport, and hydration.

The effect of in vivo x-irradiation on rabbit lens permeability was studied by the Rb runout method. At 24 hours following x-irradiation of the lens the rate of Rb runout was found to be increased and reached a maximum at one week. Over the subsequent 2 weeks the rate of Rb runout decreased, although still remaining above normal. The increase in lens permeability preceded the appearance of lens opacities and was found to be dose dependent. The active transport of cations as measured by Rb uptake was unaffected. Alteration in lens permeability was accompanied by an increase in lens water. The effect of in vitro B irradiation on the permeability of the anterior or posterior lens surface was investigated and found to parallel in vivo x-irradiation to the entire lens.