title: Meibum Color and Free Fatty Acid Composition in Patients With Meibomian Gland Dysfunction.
abstract: OBJECTIVE
  We measured the components of meibum in patients with meibomian gland dysfunction (MGD) and control subjects and then examined the relation between meibum composition and clinical parameters.
  
  
  METHODS
  Thirty-eight patients with MGD (13 men and 25 women; mean age ± SD, 66.9 ± 15.0 years) and 20 control subjects (8 men and 12 women; 64.5 ± 6.7 years) were enrolled. Ocular symptom score, keratoconjunctival staining score, tear film breakup time, and Schirmer's test value were determined. Lid margin abnormalities and meibomian gland morphology were assessed for upper and lower eyelids, and meibum properties were evaluated at temporal, central, and nasal sites of each lid. Free fatty acid (FFA) composition of meibum was analyzed by liquid chromatography-Fourier transform mass spectrometry.
  
  
  RESULTS
  Upper meibum color score was significantly correlated with epiphora and sticky sensation in MGD patients. Meibum grade, color, or viscosity did not differ significantly among the sites evaluated. A total of 103 species of FFA--including very long chain (such as C36 and C37) and odd-numbered chain (such as C17, C19, and C21) FFAs--were detected in meibum. Free fatty acid composition differed between clear and colored (cloudy or yellow) meibum, with unsaturated FFAs tending to be more abundant in colored meibum.
  
  
  CONCLUSIONS
  Free fatty acid composition of human meibum correlates with meibum color as determined with a slit-lamp microscope. This finding may provide insight into the pathogenesis of MGD.
authors.affiliation: Department of Ophthalmology, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan 2Department of Ophthalmology, Itoh Clinic, Minuma-ku, Saitama City, Saitama, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Arita
authors.affiliation: Research and Development Division, Santen Pharmaceutical Co. Ltd., Kita-ku, Osaka, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Mori
authors.affiliation: Department of Ophthalmology, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Rika
authors.initials: R
authors.lastname: Shirakawa
authors.affiliation: Research and Development Division, Santen Pharmaceutical Co. Ltd., Kita-ku, Osaka, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Asai
authors.affiliation: Research and Development Division, Santen Pharmaceutical Co. Ltd., Kita-ku, Osaka, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Imanaka
authors.affiliation: Research and Development Division, Santen Pharmaceutical Co. Ltd., Kita-ku, Osaka, Japan.
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Fukano
authors.affiliation: Research and Development Division, Santen Pharmaceutical Co. Ltd., Kita-ku, Osaka, Japan.
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Inouye Eye Hospital, Chiyoda-ku, Tokyo, Japan 5Miyata Eye Hospital, Miyakonojo City, Miyazaki, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Amano
mesh_terms: D000368:Aged; D003116:Color; D003430:Cross-Sectional Studies; D005141:Eyelid Diseases / Q000175:diagnosis* / Q000378:metabolism; D005143:Eyelids / Q000473:pathology*; D005230:Fatty Acids, Nonesterified / Q000032:analysis*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008055:Lipids / Q000032:analysis; D008297:Male; D008537:Meibomian Glands / Q000378:metabolism / Q000473:pathology*; D008875:Middle Aged; D012189:Retrospective Studies; D013666:Tears / Q000737:chemistry*
chemical_list: D005230:Fatty Acids, Nonesterified; D008055:Lipids