Biochemical Correlations During the Senile Opacification of the Human Lens

Abstract

The levels of Na⁺, K⁺, Ca⁺⁺, ribonuclease activity, soluble and insoluble proteins have been determined in unselected senile cataractous human lenses and in non-cataractous postmortem lenses. The lenses were classified according to increasing opacification of the cortex after in vivo slit-lamp examination, and on the basis of increasing pigmentation of the nucleus of the extracted lens. The results indicate that alterations in the level of lenticular cations correlate very significantly with the degree of opacification of the lens cortex and with the progressive decrease in soluble proteins. Increased lens Na⁺ was found to be the most reliable biochemical index of cortical opacification. Increased water-insoluble proteins are essentially associated with the opacification and darkening of the lens nucleus. On a per lens basis, the increase in insoluble proteins is not correlated with the absolute decrease in soluble proteins.