title: Differences in meibomian fatty acid composition in patients with meibomian gland dysfunction and aqueous-deficient dry eye.
abstract: OBJECTIVE
  To evaluate the differences in meibomian fatty acid composition in healthy subjects and in patients suffering from meibomian gland dysfunction or aqueous-deficient dry eye.
  
  
  METHODS
  We collected meibomian oil using a sterile Schirmer paper in healthy individuals (n = 20), dry eye patients (aqueous-deficient) (n = 32) and meibomian gland dysfunction (MGD) patients (n = 25) after gentle massage of the lid margin. Meibomian fatty acids were directly transmethylated and analysed using gas chromatography (GC) and GC mass spectrometry.
  
  
  RESULTS
  Meibomian fatty acids were similar in healthy individuals and in dry eye patients but were different in MGD patients, who showed significantly higher levels of branched-chain fatty acids (29.8% vs 20.2%) (p<0.0001) and lower levels of saturated fatty acids (9.3 vs 24.6%) (p<0.0001), in particular lower levels of palmitic (C16) and stearic (C18) acids.
  
  
  CONCLUSIONS
  The increase in branched-chain fatty acids may reflect greater quantities of wax and cholesterol esters and triglycerides in meibomian gland excreta. Since wax and cholesterol esters are the main lipids of meibum, these differences may have physical consequences for tear-film lipid-layer fluidity and stability. Meibomian fatty acid composition and particularly the increase in branched chains could be a marker for meibomian gland dysfunction.
authors.affiliation: Eye and Nutrition Research Group, National Institute for Research on Agronomy, Dijon, France. cjoffre@dijon.inra.fr
authors.forename: C
authors.initials: C
authors.lastname: Joffre
authors.forename: M
authors.initials: M
authors.lastname: Souchier
authors.forename: S
authors.initials: S
authors.lastname: Grégoire
authors.forename: S
authors.initials: S
authors.lastname: Viau
authors.forename: L
authors.initials: L
authors.lastname: Bretillon
authors.forename: N
authors.initials: N
authors.lastname: Acar
authors.forename: A M
authors.initials: AM
authors.lastname: Bron
authors.forename: C
authors.initials: C
authors.lastname: Creuzot-Garcher
mesh_terms: D000368:Aged; D002849:Chromatography, Gas / Q000379:methods; D015352:Dry Eye Syndromes / Q000378:metabolism*; D005141:Eyelid Diseases / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis* / Q000737:chemistry; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D008297:Male; D008537:Meibomian Glands / Q000737:chemistry*; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D005227:Fatty Acids