title: De-misting condensation on intraocular lenses.
abstract: BACKGROUND
  Condensation occurs rapidly on intraocular lenses (IOLs), particularly silicone IOLs, after vitrectomy and fluid-air exchange in the presence of a posterior capsulotomy and severely limits the surgeon's view of the retina. This study investigated the value of heating contact lens irrigation fluid to prevent condensation on IOLs.
  
  
  METHODS
  An experimental in vitro study and a noncomparative interventional case series.
  
  
  METHODS
  Five control eyes had temperature measurements during fluid-air exchanges. Two patients with silicone IOLs and posterior capsulotomies underwent a vitrectomy involving a fluid-air exchange with heated contact lens fluid.
  
  
  METHODS
  An in vitro model allowed monitoring of temperature and humidity changes during condensation formation on four different IOL materials. Adjusting variables to promote evaporation rather than condensation was achieved in vitro. In vivo, intraocular temperatures were measured at various stages of five vitrectomies involving a fluid-air exchange. Finally, in two in vivo cases a blood warmer was used to heat the accessory contact lens irrigation fluid during the vitrectomy and fluid-air exchange.
  
  
  METHODS
  Successful prevention of condensation on the silicone IOL during the fluid-air exchange.
  
  
  RESULTS
  Anterior segment temperature influences the IOL temperature, such that when it is higher than the posterior segment temperature, condensation does not form and evaporation is promoted. In vivo the temperatures in the eye are hypothermic throughout the vitrectomy. At fluid-air exchange the posterior segment heats rapidly as irrigation ceases and low specific heat gas enters. Finally, in two in vivo cases with silicone IOLs, condensation was predicted then prevented by our intervention for the duration of the fluid-air exchange.
  
  
  CONCLUSIONS
  Heating the anterior segment by conduction from warmed irrigation fluid flowing through the irrigating contact lens represents a cheap, noninvasive, and safe means to prevent condensation on IOL materials.
authors.affiliation: The Royal Brisbane Hospital, Ophthalmology Department, Herston, Australia.
authors.forename: R G
authors.initials: RG
authors.lastname: Porter
authors.forename: J D
authors.initials: JD
authors.lastname: Peters
authors.forename: R D
authors.initials: RD
authors.lastname: Bourke
mesh_terms: D001831:Body Temperature; D006358:Hot Temperature; D006813:Humidity; D007431:Intraoperative Complications / Q000517:prevention & control*; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008768:Methylmethacrylates; D011102:Polyhydroxyethyl Methacrylate; D019904:Polymethyl Methacrylate; D012826:Silicone Elastomers; D007507:Therapeutic Irrigation; D014786:Vision Disorders / Q000517:prevention & control*; D014821:Vitrectomy / Q000009:adverse effects; D014835:Volatilization
chemical_list: D008768:Methylmethacrylates; D012826:Silicone Elastomers; D011102:Polyhydroxyethyl Methacrylate; D019904:Polymethyl Methacrylate