A study of the chemistry of the blood in patients suffering from senile cataract was undertaken because we felt that since this type of cataract is always bilateral, it must be due to systemic changes. It was thought that changes in the blood might possibly point out lines of study which would eventually lead to a discovery of the etiology of these senile changes so frequently seen in the crystalline lens.
As far back as 1881, Cahn,1 in Hoppe-Seyler's laboratory, following some earlier observations of Jacobsen, reported data on the composition of cataractous lenses, in comparison with those of normal eyes. In lenses exhibiting cataractous changes the figures show a marked increase in all lipids: cholesterol, lecithin and fats. The increase in cholesterol is particularly striking, being 0.62 per cent per hundred parts of the solid residue in normal lenses and 6.22 per cent in cataractous lenses.