The mechanism of Senile Cataract

Abstract

The features of senile cortical cataract are produced by colloidal fluid which has been extruded from its combination with the lens protein or has been attracted through the capsule which has been changed in its permeability. In the incipient stage, this fluid may produce an ill-defined cortical haze or may diffuse along interfibrillar spaces to reach the capsule where it collects in the form of the so-called vacuoles or globules, or it may distend the sutures or interlamellar spaces to form the familiar water-split sutures or separated lamellae. Senile nuclear cataract represents an excessive sclerosis and dehydration of the nuclear and later of the cortical lens material. Study of the formation of cataract in tetany led to the opinion that a disturbance of the inorganic ions takes place, which is sufficient to affect the transparency of the labile colloidal solution of the lens protein. Cataracts in diabetics present features similar to those of the senile cortical form. The hypothesis is expressed that the various phenomena exhibited in the mechanism of senile cataract are those of disturbances of permeability. The structures affected in the eye are the blood vessels and the tissues of the semi-permeable ciliary epithelial membrane, the lens capsule, the lens fibers and the interfibrillar diffusion spaces. The cause of these disturbances in permeability may be chemical, physical or dependent on metabolic changes in the general system. The material for this thesis was gathered while the author was Research Fellow for the American Academy of Ophthalmology and Oto-Laryngology. From the Department of Ophthalmology, College of Physicians and Surgeons, Columbia University. Read before the Association for Research in Ophthalmology, in Milwaukee, June 13, 1933.