Effect of sodium iodate injection on the development of galactose cataract in the rat.

The effect of sodium iodate injection on the development of galactose cataract in the rat was investigated clinically and biochemically. Galactose cataracts were induced in animals which had been injected with a single dose of sodium iodate and compared with those given a saline injection. The degeneration of retinal pigment epithelium was observed electron microscopically after sodium iodate injection. A slit lamp examination of the lens showed that, in animals injected with sodium iodate, galactose-associated lens alterations progressed faster, and mature cataract development was achieved earlier than in the saline-injected animals. Biochemical data which indicated a significantly higher concentration of Na+ and lower concentration of K+ in lenses of sodium iodate-injected animals confirmed the above clinical data. The level of galactitol was higher in lenses of sodium iodate-injected than those of saline-injected animals. Acceleration of the development of galactose cataract following sodium iodate injection is apparently due to the higher level of galactose entering the aqueous humor because of breakdown of blood-ocular barriers.