The Biochemistry of the Lens: III. Water equilibrium in the normal and cataractous lens

Abstract

The lens has less water than any other tissue, but its curve of water content from the embryonic to the adult stage parallels, in general, that of the body. The soluble and insoluble proteins continuously increase in absolute amounts, but the metabolically active crystallins increase in direct proportion to the increase in lens surface, while the metabolically inactive albumoid accumulates in proportion to the square of the lens weight. The water content of the lens is determined by the balance of osmotic, imbibitional, and tension forces. In cataracts and in autolyzed lenses the normal balance between osmosis and imbibition is upset, in that an increased osmosis accompanies a lessened imbibitional power. The cataractous change is intimately dependent upon autolysis; the numerous biochemical deviations discovered are explained as the result of processes conditioning, involving, or ensuing from autolysis, whose primary prerequisite is local acidosis. From the Department of Ophthalmology, Northwestern University Medical School. Read before the Association for Research in Ophthalmology, in Milwaukee, June 13, 1933.