title: Experimental measure of retinal impact force resulting from intraocular foreign body dropped onto retina through media of differing viscosity.
abstract: BACKGROUND
  To evaluate and compare the perfluorocarbon liquid, silicone oil, and viscoelastic against standard saline, in their ability to dampen the impact force of a foreign body, dropped within the eye. In an experimental surgical model in where cohesive and adhesive forces of the substances are not enough to float heavy-than-water foreign bodies.
  
  
  METHODS
  A model of ophthalmic surgery was constructed. A BB pellet was dropped from 24 mm onto a force transducer through four different fluids: balanced salt solution, perfluoro-n-octane, viscoelastic, and silicone oil. The impact energy (force) for each case was measured and recorded by the force transducer. The mean force of impact for each fluid was compared using the Student t-test.
  
  
  RESULTS
  Silicone oil resulted in the lowest force of impact. Both silicone oil and viscoelastic dampened the impact an order of magnitude more than perfluoro-n-octane and balanced salt solution.
  
  
  CONCLUSIONS
  Silicone oil and viscoelastic cushioned the force from a dropped BB. They may be useful adjuncts to prevent iatrogenic retinal injury during vitrectomy for intraocular foreign body removal.
authors.affiliation: Department of Ophthalmology, University of Colorado School of Medicine, Rocky Mountain Lions Eye Institute, Aurora, USA.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Ernst
authors.forename: Raul
authors.initials: R
authors.lastname: Velez-Montoya
authors.forename: Damir
authors.initials: D
authors.lastname: Kujundzic
authors.forename: Elmira
authors.initials: E
authors.lastname: Kujundzic
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Olson
mesh_terms: D000085:Acetates; D004338:Drug Combinations; D005129:Eye Foreign Bodies / Q000175:diagnosis*; D015807:Eye Injuries, Penetrating / Q000175:diagnosis*; D005466:Fluorocarbons / Q000737:chemistry*; D006112:Gravitation; D006801:Humans; D008903:Minerals; D008954:Models, Biological; D012160:Retina / Q000293:injuries*; D012827:Silicone Oils / Q000737:chemistry*; D012965:Sodium Chloride; D013046:Specific Gravity; D014160:Transducers, Pressure; D014783:Viscosity; D055675:Viscosupplements / Q000737:chemistry*
chemical_list: D000085:Acetates; C030660:BSS solution; D004338:Drug Combinations; D005466:Fluorocarbons; D008903:Minerals; D012827:Silicone Oils; D055675:Viscosupplements; D012965:Sodium Chloride; C073608:perfluorooctane