The formation of a sudanophilic lipid by cells of the cornea when supplied with oleic acid or sodium oleate was first reported by Cogan and Kuwabara, in 1954.1,2 Subsequent studies of this phenomenon, termed by them "aberrant lipogenesis," recently have been summarized by them in a series of papers analyzing observations on the serum,3 substrate,4 and tissue5 factors involved. In these studies oleate-induced formation of lipid was demonstrated primarily by the accumulation of sudanophilic material within the cells.
Although Sudan staining has been widely used for the detection of lipids, it does not identify the type of lipid found in the corneal cells. It is conceivable that these cells, rather than synthesizing lipid, were concentrating the oleic acid as such in a manner similar to that which has been shown for amino acids.6 Aware of this alternative explanation of their findings, Cogan and Kuwabara supported
HILL K, KINOSHITA JH, KUWABARA T. Experimental Aberrant LipogenesisV. Biochemical Evidence of Oleate-Induced Lipid Formation in the Cornea. AMA Arch Ophthalmol. 1959;61(3):361-365. doi:10.1001/archopht.1959.00940090363003