title: The evaluation of a humidifying device for vitreoretinal surgery.
abstract: OBJECTIVE
  To study the feasibility of humidifying air during vitreoretinal surgery and measure the water content of air before and after intraocular transit.
  
  
  METHODS
  The absolute water content of air was measured in a series of six eyes undergoing fluid-air exchange during macular hole surgery. Infrared absorption spectroscopy was used to determine the water content of the air infusing and exiting each eye. After baseline measurements for each eye were recorded, a second fluid-air exchange was performed and the effect of humidifying the air infusion was documented. The humidifying device used in this study was a prototype adapted from a commercially available respiratory humidifier and enables humidified air to be delivered at a controlled temperature.
  
  
  RESULTS
  The water content of air increased following intraocular transit, implying dehydration occurs from the intraocular surfaces. For a standard airline infusion the mean increase in water content of air egressing from an eye was 13.4 mg/l. Humidifying the air reduced the rate of water loss by nearly 90%.
  
  
  CONCLUSIONS
  Significant water losses can occur from eyes undergoing fluid-air exchange. Humidifying the infused air can substantially reduce the dehydrating effect during an air exchange. This outcome may have a beneficial effect in reducing cataract formation and visual field defects associated with macular hole surgery.
authors.affiliation: Department of Ophthalmology, and Auckland Eye Department, Auckland Hospital, Auckland, New Zealand.
authors.forename: B J T
authors.initials: BJ
authors.lastname: Vote
authors.forename: M K
authors.initials: MK
authors.lastname: Russell
authors.forename: A
authors.initials: A
authors.lastname: Newland
authors.forename: P J
authors.initials: PJ
authors.lastname: Polkinghorne
mesh_terms: D000388:Air; D003681:Dehydration / Q000503:physiopathology; D005069:Evaluation Studies as Topic; D005123:Eye / Q000503:physiopathology; D005240:Feasibility Studies; D006801:Humans; D006813:Humidity; D013508:Ophthalmologic Surgical Procedures / Q000295:instrumentation* / Q000379:methods; D012167:Retinal Perforations / Q000503:physiopathology / Q000601:surgery*; D014867:Water / Q000032:analysis
chemical_list: D014867:Water