title: [Tear substitutes. Experimental and clinical observations].
abstract: Dry-eye conditions do not represent an etiologically homogeneous clinical picture, and therapy is therefore difficult. Tear substitution by means of artificial tears of various viscosities has been common practice, and the use of highly viscous artificial tears is considered appropriate therapy in many cases of dry eye because of their prolonged contact time on the ocular surface. A clinical study with a gel made of cross-linked polymers of acrylic acid with a high molecular weight (Thilo-Tears) showed that both the subjective and objective effects were good. Clinical parameters and data describing the differences in contact times of the highly viscous preparations and a low-viscosity solution (2% PVP), Schirmer's test, Jones's test, and BUT are described and assessed in detail. Furthermore, an attempt is made to supplement and corroborate the clinical findings and the rationale of using highly viscous solutions by presenting experimental results on the preocular film. In particular, considerations pertaining to the relevance and the formation of the glycocalyx from vesicles of corneal epithelial cells are discussed, and the interaction of the epithelial cell membranes with the preocular film is emphasized.
authors.affiliation: Augenklinik der Medizinischen Hochschule Hannover.
authors.forename: H
authors.initials: H
authors.lastname: Brewitt
mesh_terms: D000328:Adult; D005260:Female; D005782:Gels; D006801:Humans; D008297:Male; D013501:Surface-Active Agents / Q000008:administration & dosage*; D013666:Tears / Q000378:metabolism; D014783:Viscosity; D014906:Wetting Agents / Q000008:administration & dosage*; D014985:Xerophthalmia / Q000209:etiology / Q000628:therapy*
chemical_list: D005782:Gels; D013501:Surface-Active Agents; D014906:Wetting Agents
vernacular_title: Tränenersatzmittel. Experimentelle und klinische Beobachtungen.