Abstract
The tear film protecting the ocular surface is a largely aqueous layer of protein and mucins. Overriding this film is an insoluble layer of meibomian lipids and serves to enhance the stability of the tear film by slowing down evaporation and inhibiting breakage and dewetting. These lipids are supplied to the system by glands on our eyelids. In cases where the stability of the tear film is not achieved, it will break and dry eye syndrome can ensue. Problems associated with dry eye are particularly frequent when contact lenses are used.
This paper describes experiments where the drainage and dewetting are measured above silicone hydrogel (SiHy) contact lenses in the presence of insoluble layers. It is demonstrated that the interfacial rheology of these layers (meibum and DPPC layers are studied) is central to their ability to stabilize aqueous layers against drainage and dewetting.
In addition, the propensity of contact lenses to become spoiled by naturally occurring ocular constituents have a very important role in maintaining stability against dewetting. It is demonstrated by meibum, DPPC, and cholesterol can become adsorbed on the surface of contact lenses and, in some cases, these adsorbed layers can have a deleterious effect on film stability.
About the speaker
Prof Gerald Fuller received his PhD in Chemical Engineering from the California Institute of Technology in 1980. He joined Stanford University since then, and is currently Fletcher Jones II Professor of Chemical Engineering.
Prof Fuller's research interests lie in studies of rheology and interfacial fluid mechanics. His lab has developed many new techniques to identify and study the behavior of complex materials, fluids and fluid surfaces. His work led to a variety of innovations in areas ranging from the processing of plastics and improved optimization of droplets in ink-jet printers to creating new solutions for dry-eye syndrome and improving tear film stability.
Prof Fuller received prestigious awards including the Bingham Medal from the Society of Rheology, Cox Medal for Excellence in Fostering Undergraduate Research and the NSF Presidential Young Investigator Award. He was named one of the "One Hundred Engineers of the Modern Era" by the American Institute of Chemical Engineers (AIChe). He is a Member of the US National Academy of Engineering and AIChe, and a Fellow of the American Physical Society.
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