title: The real reason for having a meibomian lipid layer covering the outer surface of the tear film - A review.
abstract: This review critically evaluates a broad range of literature in order to show the relationship between meibum, tear lipids and the tear film lipid layer (TFLL). The relationship of meibum composition to dry eye syndrome is briefly discussed. The review also explores the interactions between aqueous and the TFLL by examining the correlations between meibomian lipids and lipids extracted from whole tears, and by considering protein adsorption to the TFLL from the aqueous. Although it is clear to the authors that a normal tear film resists evaporation, an emerging idea from the literature is that the main purpose of the TFLL is to allow the spread of the tear film and to prevent its collapse onto the ocular surface, rather than to be an evaporative blanket. Current models on the possible structure of the TFLL are also examined.
authors.affiliation: University of Western Sydney, School of Science and Health, Locked Bag 1797, Penrith, NSW 2751, Australia. Electronic address: t.millar@uws.edu.au.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Millar
authors.affiliation: University of Western Sydney, School of Science and Health, Locked Bag 1797, Penrith, NSW 2751, Australia. Electronic address: b.schuett@uws.edu.au.
authors.forename: Burkhardt S
authors.initials: BS
authors.lastname: Schuett
mesh_terms: D015352:Dry Eye Syndromes / Q000378:metabolism*; D006801:Humans; D008055:Lipids / Q000032:analysis*; D008537:Meibomian Glands / Q000737:chemistry*; D013499:Surface Properties; D013666:Tears / Q000737:chemistry*
chemical_list: D008055:Lipids
keywords: Blepharitis; Dry eye; Evaporation; Mucin; Ocular surface; Tear film; Thin films