There's a new lipid in town

A new class of lipids, that makes up part of the tear film, has been identified, which could lead to insights into the role of fatty acid amide activity in the human biological system, according to a study published in the January 2007 issue of Investigative Ophthalmology and Visual Science.

Kelly Nichols and colleagues from the College of Optometry at the Ohio State University, USA, analysed human meibomian gland secretions using electrospray quadrupole time-of-flight mass spectrometry. Mass determination and collision-induced dissociation of meibum and lipid standards were used to identify lipid species.

The researchers findings indicate that oleamide, an endogenous fatty acid primary amide, is a predominant component of meibum. It is already known that oleamide plays a role in the brain, where it helps induce sleep, but this is the first study to identify it in the tear film of the eye.

The researchers hope that further investigation will allow them to work out the lipid?s exact role in the eye.