title: Expansion of intraocular gas bubbles due to altitude: do meteorological factors play a role?
abstract: BACKGROUND
  Intraocular gas bubbles expand as patients move up to higher altitude. This may cause an acute intraocular pressure (IOP) rise with associated vascular obstructions and visual loss.
  
  
  METHODS
  Two pseudophakic patients underwent a pars plana vitrectomy and 23% SF6 gas tamponade for a pseudophakic retinal detachment. During the immediate post-operative phase, the patients travelled daily up to their domicile, which was situated approximately 600 m higher than the level where they had been operated on. These travels were always without any pain or visual loss. However 1 week after surgery both patients developed severe ocular pain, and one patient had complete temporary loss of vision after ascending to altitude levels, which had previously presented no problem. Both episodes occurred in parallel with a change in barometric pressure.
  
  
  RESULTS
  Treatment with acetazolamide reduced the increased IOP to normal levels, and visual acuity recovered.
  
  
  CONCLUSIONS
  Although the post-operative size of an intraocular gas bubble decreases progressively over time, problems with bubble expansion may still occur even at a late stage if meteorological factors, that may increase the bubble size, change.
authors.affiliation: Jules Gonin Eye Hospital, University of Lausanne, Lausanne, Switzerland.
authors.forename: W
authors.initials: W
authors.lastname: Ferrini
authors.forename: J A
authors.initials: JA
authors.lastname: Pournaras
authors.forename: T J
authors.initials: TJ
authors.lastname: Wolfensberger
mesh_terms: D000531:Altitude; D005466:Fluorocarbons / Q000009:adverse effects*; D005740:Gases; D006801:Humans; D009798:Ocular Hypertension / Q000175:diagnosis* / Q000209:etiology* / Q000517:prevention & control; D012307:Risk Factors
chemical_list: D005466:Fluorocarbons; D005740:Gases