The fatty acid amides, first identified in the human cerebrospinal fluid, are generally associated with the initiation of sleep. But researchers at Ohio State University have now found fatty acid amides in the human tear film, and one in particular: oleamide.


In the new study, researchers analyzed human meibomian gland secretions (meibum) in hopes of identifying the specific fatty acid amides present in the meibum.

They found that oleamide is actually a major component of these secretions, but that myristamide, palmitamide, stearamide and erucamide were also present in smaller amounts.


Oleamide may assist in maintaining the tear film or serve a purpose in cellular signaling. Our work has shown that the fatty acid amides, in particular oleamide, are present in the tear film, says lead researcher Kelly Nichols, O.D., M.P.H., Ph.D. Understanding the relation between the fatty acid amide and other lipid and protein molecules in the tear film is very interesting and is a direction we are excitedly pursuing.


This discovery may lead to new dry eye therapy. The identification of oleamide in the tear film may impact the current understanding of tear film stability, which in turn could affect diagnosis and management of dry eye. Understanding the role of lipid biomarkers in the tear film may lead to the development of tests specific for dry eye diagnosis or monitoring, and to the development of novel treatments, Dr. Nichols says.

 

Nichols KK, Ham BM, Nichols JJ, et al. Identification of fatty acids and fatty acid amides in human meibomian gland secretions. Invest Ophthalmol Vis Sci 2007 Jan;48(1):34-9.

Vol. No: 144:02Issue: 2/15/2007