title: Development of emulsification resistant heavier-than-water tamponades using high molecular weight silicone oil polymers.
abstract: OBJECTIVE
  Developing new blends of heavier-than-water silicone oil tamponade agents containing high molecular weight polydimethylsiloxane polymer for use in vitreoretinal surgery.
  
  
  METHODS
  The viscoelastic properties of heavier-than-water silicone oil blends (30.5% F6H8 + 69.5% polydimethylsiloxane) containing high molecular weight polymer additive at increasing concentrations were measured using a controlled-stress rheometer (TA Instruments Rheolyst AR 1000 N). Emulsification of the blends was induced using a sonication device and a pluronic surfactant as a strong emulsifier. The percentage emulsion area was photographed and measured using ImageJ software. In a second in vitro emulsification assessment, silicone oil blends were dispersed using a high shear homogenizer and the oil-in-water droplets were counted using a coulter counter particle analyser.
  
  
  RESULTS
  The addition of the high molecular weight polymer increased shear viscosity and viscoelasticity of the oil blends, which were measureable and to some extent predictable. The in vitro emulsification models produced contradictory results. This demonstrates the difficulty of designing and using in vitro models to evaluate the emulsification tendency of tamponade agents in vivo.
  
  
  CONCLUSIONS
  Addition of a high molecular weight polymer to heavy silicone oil can increase the viscoelasticity. These findings might contribute to the development of emulsification resistant heavy silicone oils.
authors.affiliation: Department of Ophthalmology, University of Cologne, Cologne, Germany.
authors.forename: Albert
authors.initials: A
authors.lastname: Caramoy
authors.affiliation: Department of Eye and Vision Science, University of Liverpool, Liverpool, United Kingdom vkearns@liv.ac.uk.
authors.forename: Victoria R
authors.initials: VR
authors.lastname: Kearns
authors.affiliation: Eye Institute, University of Hong Kong, Pokfulam, Hong Kong.
authors.forename: Yau Kei
authors.initials: YK
authors.lastname: Chan
authors.affiliation: Fluoron GmbH, Ulm, Germany.
authors.forename: Nadine
authors.initials: N
authors.lastname: Hagedorn
authors.affiliation: School of Engineering, University of Liverpool, Liverpool, United Kingdom.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Poole
authors.affiliation: Department of Eye and Vision Science, University of Liverpool, Liverpool, United Kingdom Eye Institute, University of Hong Kong, Pokfulam, Hong Kong.
authors.forename: David
authors.initials: D
authors.lastname: Wong
authors.affiliation: Department of Ophthalmology, University of Cologne, Cologne, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Fauser
authors.affiliation: Fluoron GmbH, Ulm, Germany.
authors.forename: Wilfried
authors.initials: W
authors.lastname: Kugler
authors.affiliation: Department of Ophthalmology, University of Cologne, Cologne, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Kirchhof
authors.affiliation: Department of Eye and Vision Science, University of Liverpool, Liverpool, United Kingdom.
authors.forename: Rachel L
authors.initials: RL
authors.lastname: Williams
mesh_terms: D004655:Emulsions; D008970:Molecular Weight; D011108:Polymers / Q000737:chemistry*; D012212:Rheology; D012827:Silicone Oils / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D004655:Emulsions; D011108:Polymers; D012827:Silicone Oils; D014867:Water
keywords: Ophthalmology; emulsification; retinal detachment; silicone oil; tamponade