title: Interaction between perfluorcarbon liquid and heavy silicone oil: risk factor for "sticky oil" formation.
abstract: OBJECTIVE
  To investigate in vitro the interaction between perfluorcarbon liquids (PFCLs) and heavy silicone oils (HSOs).
  
  
  METHODS
  Interactions between different kinds of PFCL [perfluoro-n-octane (PFO) or perfluorodecaline (PFD)] and HSO (either alkane or ether) were studied in vitro by incubating fluids for 7 days at regulated temperatures. The samples were divided into two groups: Group A, PFCL (PFO or PFD) + 5 ml of HSO (silicone oil + alkane or ether) and Group B, HSO (silicone oil + alkane or ether) without PFCL. Each sample was kept at 36°C for 7 days. HSOs were then removed with a 20 g, 7 mm-long cannula under 600 mm Hg of vacuum pressure at two different temperatures: 36 and 22°C. The time needed to remove the oils and the presence of opacity was recorded. Each experiment was repeated three times.
  
  
  RESULTS
  In vitro, interactions between PFCL and HSO oil led to the formation of hyper-viscous solutions with significative increase in aspiration time in Group A. (P = 0.006, Kruskal-Wallis test) Temperature was also found to affect HSOs' saturation, as a decrease in temperature determined an increase in opacity and shear viscosity of the solution (P = 0.02, Kruskal-Wallis test). No differences between alkane and ether (P = 0.74) and n-octane and decaline (P = 0.56) was found.
  
  
  CONCLUSIONS
  Interactions between PFCL-HSO and variation in temperature lead to the formation of hyper-viscous solutions that could be described as "sticky oil".
authors.affiliation: Department of Ophthalmology, Istituto Clinico Humanitas , Rozzano, Milan, Italy. romanomario@email.it
authors.forename: Mario R
authors.initials: MR
authors.lastname: Romano
authors.forename: Jose L
authors.initials: JL
authors.lastname: Vallejo-Garcia
authors.forename: Francesco
authors.initials: F
authors.lastname: Parmeggiani
authors.forename: Vito
authors.initials: V
authors.lastname: Romano
authors.forename: Romano
authors.initials: R
authors.lastname: Vito
authors.forename: Paolo
authors.initials: P
authors.lastname: Vinciguerra
mesh_terms: D004347:Drug Interactions; D004655:Emulsions; D005466:Fluorocarbons / Q000737:chemistry*; D012307:Risk Factors; D012827:Silicone Oils / Q000737:chemistry*; D012995:Solubility; D013696:Temperature; D014783:Viscosity
chemical_list: D004655:Emulsions; D005466:Fluorocarbons; D012827:Silicone Oils; C515608:densiron; C008805:perfluorodecalin; C073608:perfluorooctane