The Lipids of the Retina.*

Abstract

For a long time, the retina has been known to contain a remarkably high percentage of lipids in the rods, cones, cells and nerve fibers. It is obvious that knowledge concerning these lipids is necessary in order to understand more completely the nature of retinal diseases.At present very little is known about the retinal lipids. Only two papers dealing with the quantitative analysis have been published. The first investigation of the lipids was re5 ported (by Cahn ( I , ) who found 0.71 per cent cholesterol, 2.48 per cent lecithin and 0.40 per cent fat in the moist ox retina; 0.27 per cent cholesterol, 0.95 per cent lecithin and 0.05 per cent fat in the moist pig retina; and 2.39 per cent lecithin in the moist horse retina. He also believed that he detected the presence of cerebrin. Later, Lo Cascio (2) also endeavored to separate the lipids. He estimated that the dry bovine retina contained 25.7 per cent total lipids, 1.6 per cent cholesterol and 13.7 per cent phospholipids, and the optic nerve 54.3 per cent total lipids, 14.09 per cent cholesterol and 24.7 per cent phospholipids. However, these reports give slight indication of the complex nature of the retinal lipids. The purpose of this paper is to report in more complete manner the nature and distribution of the retinal lipids. The experimental procedure which was used for the determination of the nature and quantitative distribution of the bovine retinal lipids was published in a previous article on the lipids of the bovine sclera, cornea, choroid and iris (3). The distribution *) Received 24th of August 1934. From the Wilmer Ophthalmological Institute of the Johns Hopkine University and Hospital.